Danger in the Air – Anatomy of an Occupational Hazard

When flying as a passenger in a commercial jet aircraft is there any danger in breathing in the air?  Although you will be told aircraft air is pretty clean – cleaner than the air in your home and office, is this always true?

Except for the Boeing B.787 Dreamliner, commercial aircraft pump all the air we breathe from a place deep inside each jet engine, only separated from hot jet engine oil by seals that get worn and should be replaced at regular intervals but owing to the cost of doing so these intervals in maintenance have tended to become longer and longer.    When these seals become worn, toxic contaminant particles and gas can now get from the oil into the aircraft air in increasing number.

The poisonous gas carbon monoxide, certain other potentially toxic compounds including organophosphates in small amounts, and finally ultrafine particles are found in aircraft air – unfortunately, none of these are large enough to be stopped by filters. The airline industry appears not to have investigated these issues nor has it provided reliable evidence.

The poisonous items in the aircraft air vary in concentration according to how worn the sealing systems have become.  On occasion, so many contaminants enter the air, a ‘fume event’ occurs – here the air may have started to smell and can become visibly hazy. The only way to find out the true state of aircraft air is to fit equipment that can continuously monitor and record the presence of these toxic items in real time.  This is urgent, as a growing number of people (passengers, flight attendants and pilots) have been and are getting ill.

They present with a number of unusual but distressingly persistent complaints that affect many parts of their body in particular the brain and nervous system.  Many affected staff have been told officially they must be imagining this.  Meanwhile in 1999, this group of illnesses was published as Aerotoxic Syndrome.

In order to alleviate this state of affairs, medical protocols designed by experts should be in place, and equipment such as oxygen and other remedies should be provided to sufferers both in the aircraft and when they land.  Those patients who have suffered should not be discounted.  They should be offered what medical support there is both for them and their families.  Meanwhile the design fault that allows incoming air anywhere near hot jet engine oil needs to be re-designed in all aircraft jet engines in the future.

Abstract published in the public interest on 18 June 2022 @ 1100 UTC by: ‘A Group’ Flight Attendant Deanne DeWitt Freise with 30 years of experience investigating and advocating for improving cabin air quality in aircraft. Captain John Hoyte, Chairman Aerotoxic Association The Charity (2007) Former BAe 146 Training Captain A Group spokesman john.hoyte@aerotoxic.org  & Captain John Lind former US Aviation insurer assessor & A Group spokesman & Advocate crewadvoc8@yahoo.com 


AIR CONTAMINATION in the Air Transportation Industry. A Concise History

Presented on behalf of ill and disabled crewmembers and those who continue to be exposed to contaminated cabin air.

In Association with Aerotoxic Association Ltd The Charity (2007) Aerotoxic Solutions Consultancy Ltd. (2021)


July 2022


We in the USA, live in a nation that is afraid of itself. Our nation was founded on checks and balances to keep dangerous influences at bay, but contrary forces and a badly interpreted economic theory have overpowered our historical culture. Today we see up front and center, problems with polarized politics, innovative banking and finance, overpriced pharmaceuticals, toxic herbicides and insecticides, groundwater pollution, atmospheric warming, guns. We give lip service, but the power of big money has come to rule and silences these issues. The case presented today might be thought less important than these examples. However, it runs parallel. If we don’t face it head on, like guns and global warming, illness, injury, and disability among airline crewmembers and passengers will persist.

Our group of injured and disabled crewmembers and their advocates has studied the issue for almost 30 years. Arriving now with facts and possible solutions, we present the case for evaluation as a first step toward a satisfactory conclusion. On one hand, elimination of the problem seems at present to be economically impractical. Suggested solutions in that regard will be offered, but hope eludes. Mitigation of the deleterious effects causing injury may be much more practical and could carry the issue forward until the ultimate solution can be embraced. Peer-reviewed literature defines the method to be applied to minimize injury, disability, and death by carbon monoxide poisoning or by carbon monoxide-influenced suicide.

Victory over this pervasive occupational hazard and by common locale, a public health hazard, is the immediate goal. Access to treatment as soon as possible using 100% oxygen will arrest injury progression. This is the prime objective. Elimination of the hazard when feasible is the ultimate goal.

John M. Lind CPCU ARM     Spokesperson for the ‘A’ Group

 In alliance with 

Spokesman for the ‘A’ Group – Former BAe 146 Training Captain John Hoyte

Founder and CEO Aerotoxic Association (2007)

& Aerotoxic Solutions Consultancy (2021)

October 24, 1978

An Act of Congress


  1. 2493 – The Airline Deregulation Act of 1978, promulgated by the 95th Congress, was signed into law. This law did little more of substance than to mandate and impose upon the air transportation industry a questionable economic theory called “market competition” when heretofore the industry membership had never before in its 40-year history actually “competed”. What followed was a self-flagellation that nearly destroyed the entire industry. Only four (4) of perhaps twenty-four (24) major air carriers survived.

January 1, 1985

“Now they are on their own”, stated the last administrator of the Civil Aeronautics Board, “Free markets do a better job than government”. His falling gavel placed a period behind a history of airline regulations and micro-managerial protectionism that had governed the airline industry since its formal inception in 1938.

Chaos ensued when the air carriers of the day clashed over ticket prices in a survival-of–the-fittest contest for market share. Facing ever-decreasing revenue from the new low fares necessary for survival, aggressive cost cutting ensued. Among early cost cuts were wages, employee benefits, and customer services. Important maintenance was postponed; then curbed because of insufficient funds. State of the art evolution in high bypass turbojet engines multiplied overhaul costs to such degree that historical maintenance protocols had to be abandoned. Digital recording and communication of engine performance data gave birth to new, engine health management protocols. This set a dangerous precedent at the exact point where human health and safety began to be compromised.

The PROXIMATE CAUSE of Contaminated cabin air

1985 – 2000

Prior to the Deregulation Act of 1978 and closure of the CAB on 1/1/1985, we assume aircraft engines continued to be operated mostly within the manufacturers maintenance guidelines of approximately 5,000 hours since new or between overhauls (TBO). Exceptions would be made for the large, new generation engines powering the ‘wide-body’ Boeing 747, Douglas DC10, and Lockheed L1011. Assumedly, manufacturers would have recognized the greatly elevated overhaul costs for these large, new engines and their heavy lift airframes. New protocols for engine maintenance had been in development throughout the 1970s. The result: engine health management (EHM), condition-based maintenance (CBM), and predictive maintenance protocols. Supported by arrays of sensors monitoring engine vibration and performance, then feeding data to a collection point on the aircraft, and communicated by satellite to land based stations, these new engines could be operated safely as long as the data confirmed operation “in the green”.

Some turbojet and low bypass turbine engines might have continued to be overhauled regularly as long as funds were available to pay the cost. These costs ran approximately to $250,000. However, we speculate that high-cost journal entries of this type soon became more and more difficult to support as ticket prices fell ever lower. Aggressive cost cutting across the entire management landscape became the industry norm.  We assume also that:

  1. a) All engine maintenance gravitated toward EHM as funds became scarce.
  2. b) Engines entered the new maintenance protocol era at various logged hours of operation.
  3. c) Wear on engine parts continued uninterrupted under the new protocol.
  4. d) Seals in engine bearing compartments are located within the most dynamic gradients of temperature and pressure anywhere in the engines except the burner section.
  5. e) Engine oil leaks, and fumes were not included in the sensor array designs in the new engine monitoring systems or by sensors in the aircraft itself. Investigation of the purity of cabin air has been historically prohibited.
  6. f) The human nose and eyes were selected by default to become the early warning systems for cabin contamination.

Engine Hours On-Wing

30,000>40,000>50,000 on-wing hours 6.25 > 9.375 > 12.5 > 15.625 on-wing Years ” v:shapes=”Text_x0020_Box_x0020_9″>

Illnesses begin to appear

Symptoms begin to appear among flight attendants and some passengers.  Headache, nausea, vomiting, dizziness, deep fatigue, numbness, tingling, tremors, eye/nose/throat irritation, chest tightness, cognitive/concentration difficulties cover most of the common sensations. This list was collected from among aircrew experiences. They exactly parallel symptoms of carbon monoxide victims.

2000    –   2019

Experience among BAe 146 aircrews in Australia, the United Kingdom and elsewhere confirmed primary design problems. The aircraft was taken away from passenger services. Production halted in 2001.

Other makes and models of aircraft with bleed air served environmental control systems are not exempt from oil leaks and related toxic fumes in the cabin and flight deck. All from time to time can potentially and unpredictably impose hazardous fumes upon unsuspecting passengers and fumes do repeatedly and chronically affect crewmembers. Contaminated air in airliner cabins has progressed at a less aggressive pace but a more insidious and persistent pace than that found in the BAe 146 aircraft.

A persistent and insidious pace.

Throughout the years before deregulation up to 1980 there were no fume events at all. No work-related fumes causing employee illnesses and injuries occurred. No fume-related workers compensation claims were filed. Being Director of Safety and keen to watch for trends in injuries and illnesses on the job, I personally combed the cases over a nearly ten-year period.

Fume events began to appear after 1985 and became slightly more common by 1995. In the beginning, lawmakers, manufacturers, and airline operators were taken aback. These executives must have become concerned about discovery and probable negative public opinion. Their response was swift. They became silent. They denied and deflected. They would not openly investigate fume events. The FAA must also have investigated but to this day no opinion about contaminated cabin air has ever been offered. They continue to remain silent or otherwise deny the issue.

Early injury claims for workers compensation were declared compensable. Testimonials from those early casualties confirm payments although diagnoses and proper medical response was lacking. Again, to this day the medical response has been off target. There are no standard response procedures, no accurate diagnoses, and no proper treatment protocol.

Regulators joined the effort to deny and deflect. The FAA and NTSB hid behind Federal Air Regulation definitions by categorizing fume events as incidents. Incidents involving aircraft are not investigated because aircraft damage and physical injuries are not involved. In this way they avoid responsibility. They fail to consider that incidents precede accidents and accident prevention has never been an FAA embraced responsibility. They falsely try to assure the public and employees that nothing of concern was or is now happening on airliners. “The air in aircraft cabins is more pure than the air in your home” is the go-to explanation. “HEPA filters clean the air to operating room purity” – untrue, but good oratory all the same.

Fume incidents have increased in frequency and severity throughout the years as equipment maintenance continues to languish.  Reports are required by regulators, but compliance is weak and the rule is not enforced.

Flight attendants have gradually became more and more exposed to CO fumes on many of their flights. They remain unaware that they, above all other air travelers, are susceptible to CHRONIC EXPOSURE to the contamination – CARBON MONOXIDE CONTAMINATION.

Contamination in engine oil

Tricresyl phosphate (TCP), used in insecticides, chemical warfare agents, fire retardant, and as a friction reducer in lubricants, is listed as a warning on synthetic turbine engine oil containers. Investigators thought this must be the problem contaminant. From my personal, professional viewpoint, the industry truthfully asserted that TCP in extremely small concentrations present in engine oil could not cause illness among aircraft occupants. Such “excuse” has not been accepted by many of our associates. Nitrous oxides are also present but in still smaller quantities that need no qualification. Twenty years of investigation, crewmember testimonials, and research finally determined the toxic contaminant of most concern is carbon monoxide (CO). Simply stated, the aircraft engines and APU are prime producers of this most dangerous of gasses.

Researchers are also concerned about chemical reactions among a mix of various compounds in oil, which, although relatively benign in original forms, could interact synergistic to form increased toxic qualities, stay the same, or antagonistically to become less toxic. Such issues would need to be researched at length under many variants of chemical concentration, temperature, pressure altitude, and combination and permutations within the mix. Perhaps such a project has never anywhere been completed.

Symptoms of Carbon Monoxide

Very many crewmembers have become incapacitated by toxic fumes in aircraft. As seen previously, overhaul costs grew significantly with powerplant innovation. Unfortunately, this state-of-the-art growth in engine sophistication and performance accompanied lawmaker-mandated airfare competition between air carriers. As a direct result, the very high cost of equipment maintenance and overhaul became unaffordable. Overhauls delayed by engine health management procedures have left crewmembers the primary cost-bearers of consequential health problems. Everywhere in business, money talks. Big business is deaf to human health and safety.

Symptoms visit exposed people differently according to their unique physiology. Here listed are typical symptoms in rough order of occurrence among air travelers.











Breathing difficulty

(chest tightness)

Eye, nasal irritation

Extreme fatigue


Cognitive dysfunction






Chemical sensitivity


Death – soon or late

Suicide – soon or late

Flight attendants and pilots interviewed for this project have demonstrated and expressed all of the symptoms listed here. First occurring as undetectable carbon monoxide fumes in the late 1980s, many months and years of exposure within the aircraft environment began to compromise immune systems. Long-term, low-level (LTLL) exposure to CO induced toxicant induced loss of tolerance (TILT) among a large number of susceptible flight attendants and pilots. No one noticed. Today medical testing may be hard-challenged to prove this allegation beyond doubt. Circumstantial evidence, however, is very strong.

2010 – 2019

Seal wear increases as engines continue in revenue service with little attention by major maintenance. Increasing olfactory and visual evidence – dirty socks/no smoke, haze, localized smoke, heavy smoke – it is possible to infer a degree of damage within the main powerplants and, by virtue of time and place of occurrence, deterioration of the APU using the same subjectively visual yard stick.

Dangerous incidents and accidents occurred in the first two decades of the 21st century, some claiming lives. These cases have never been investigated and therefore we have no reference from which to estimate future accidents. Investigators need a yardstick because, without regard for injuries and disabilities, we have no hard evidence to share with regulators. Regulators everywhere then continue to support the airline industry against the “allegations” of ill employees. We have called the FAA to report these dangerous “incidents”. We have provided evidence of injuries and disabilities. The regulators have seen fume event aircraft filled to capacity with passengers nearly crash when both pilots became incapacitated at the same time. The regulators continue to ignore our evidence and these cases. They do not respond to emergency whistleblowers.

In 2019, just before the Covid 19 pandemic, fume events and injuries appeared to peak. Reportedly one airline had 60 pilots on fume-injury recovery time off. We wonder why the FAA did not ground these pilots. Is it because in the current pilot shortage a neurologically impaired pilot on the flight deck is better than no pilot at all?

Air travel then slumped. Scheduled flights were and continue to be cancelled. Fume event contingencies continue amid covid-related contingencies. Now, in 2022 normal operations strive to recover to pre-pandemic levels, but many pilots and other crew are not returning. The aircrew workspace has become much more unsafe.


Carbon Monoxide Poisoning

Suggestions for reducing toxic effects

This emergency document recognizes S.1626 – Cabin Air Safety Act of 2017. Passage into law is Imperative.

29 March 2022 proposed USA legislation Cabin Air Safety Act:


§ 45405. Air quality monitoring equipment

“(a) Requirement To Include On Aircraft.—Not later than 180 days after the date of the enactment of this section, the Administrator shall promulgate regulations requiring an air carrier, after 90 days for public comment and not later than 1 year after the regulations are finalized in the Federal Register—

“(1) to install and operate onboard detectors and other air quality monitoring equipment that—

“(A) are situated in the air supply system to enable pilots and maintenance technicians to identify the location of the source or sources of air supply contamination in real time, including any concentration of carbon monoxide that is dangerous to human health;

“(B) continuously monitor any relevant marker compound consistent with engine oil and hydraulic fluid fume concentration in the aircraft cabin and air supply system; and

“(C) alert the pilot and flight attendants to poor air quality that is dangerous to human health;

To minimize illness and disability likely to arise from carbon monoxide exposure, oxygen must be provided as soon as possible after aerial flight or encountered at or contiguous with the contaminated location.

Establish procedures and locations from which 100% oxygen can be distributed among airline employees, passengers, and ground personnel who have been exposed to carbon monoxide fumes.

Standard Procedures – an FAA responsibility to establish and enforce.

Forty years of cabin air incidents, accidents, and casualties do not lie. The task now is to recognize individual health emergencies inflight and at departure and arrival gates. Here listed are some possible response options:

FAA Standards of performance with respect to toxic fumes in aircraft

  • FAA to develop standard operating procedures for all airlines to follow during fume events. Response commences upon discovery of fumes and includes – First, establishes the captain as sole decision-making authority. Absent the captain, first officer becomes sole authority. Then, isolation of fumes, go/no go decision making, alternate landing options, request for first response emergency medical, and as may be necessary.
  • Procedures essential to differentiate toxic from benign fumes. Consider that exact identification of toxic compounds may not be possible, practical, or necessary. Carbon monoxide fumes dominate and are relatively easy to detect within the cabin air space or from an exposed individual’s exhaled breath. Relate appearance of illness symptoms. See CO – breathalyzer in appropriate attachments.
  • The standards should consider unique physiological characteristics of exposure symptoms to assure necessary and sympathetic response by appropriate specialists.
  • Recognize the response immediacy demanded by CO fumes and other contaminants, if any. For instance, CO is life threatening. Priority response is imperative.
  • Procedures should be international and developed in association with ICAO.
  • Participating parties could include representatives of airline safety departments, labor unions, airport services, and emergency response personnel.
  • General procedures to assure exposures are recognized and treated where necessary for the health of passengers as well as flight and ground employees.


Symptoms collected from casualties of so many fume events among our friends are expected to convincing. Illnesses and disabilities caused as a result of these symptoms should indicate an overpowering need to respond in ways that will prevent others from suffering into the future. The options as we see them include:

Mediate the hazard by managing the effects of the unsafe condition

This option leaves the unsafe condition untouched. Instead, using guidance found in scientific research, take steps to interdict the deleterious effects by detoxifying the blood and tissues of injured employees and passengers.

Oxygen is the one and only method of available to provide this service.

Eliminate the unsafe condition:

  • Redesign environmental control systems using non-bleed air systems. Ideas include:
  • (1) Retrofit modern turbocompressor fed ECS systems.
  • (2) Perfect an innovative idea using high bypass air as the clean air source.
  • (3) Combinations of (1) and (2).
  • Facilitate bearing seal replacement by redesigning low and high bypass engines to make disassembly at the forward compressor bearing station easier and less expensive to accomplish. This must be accomplished while the engine is on wing. Similar redesigning will be necessary for the APU.


Attached Documents

Testimonials – Media Reports – Aircraft Accident Reports.

The international airline industry, which includes its regulators, has never confirmed that any injuries have been caused by contaminated cabin air on aircraft. Therefore we must provide that evidence ourselves. Individual victims made ill and disabled tell their tails of suffering. Their histories and medical records confirm preponderantly the evidence needed to establish the truth of this public and occupational health hazard.

BBC 25 February 2020: Fume events: The toxic gases that may be harming aircrew and passengers

LA Times 31 March 2022:  After Times investigation, Congress is moving to curb toxic fumes on airplanes.

Internet 9 July 2022:  All passengers on most commercial flights are exposed to dangerous levels of carbon monoxide according to a report to be released by the Aerotoxic Association Thursday – July 14th 2022.

The Root Cause of contaminated Cabin Air

This attachment an objective view of the specific time separating the eras before and after the appearance of cabin air contamination in the airline industry. It discusses the politics of the day and discusses a dangerous 18th century economic theory, which has arguably caused great pain and suffering in the world. It questions free market enterprise and the fall of morality.

Closure of the Civil Aeronautics Board on January 1, 1985 threw the airline industry into an immediate tailspin, which resulted in the actual free market scourge that continues today.

The proximate cause of contaminated cabin air

Replacement of manufacturers time between overhaul (TBO) maintenance with the modern digital communication system of engine health management (EHM) that monitors engine performance while in flight. Possible reasons for the change and the deleterious effects it has imposed upon human health and flying safety is discussed.

Results of condition based maintenance and predictive maintenance placed into airline service without concern for health and safety is presented.

Airline industry response to competitive market forces.

Ticket prices created as intended by Congress’s mandate led to aggressive cost cutting and upside down balance sheets. A extreme lesson in very bad managerial accounting, which ended in systemic fraud. See workers compensation attachment.

Bloody warfare.

Engine and APU seals, wear, tear, engine oil, pyrolysis, particles and gasses.

Toxic fumes result. A short discussion of perpetual airline secrecy and silence about the contaminated air issue.

Era 1985 – 2000

Creeping increase of fume events – 5 attach 6

Evidence of the slow onset of cabin fumes, crewmember and airline management response, and who knew what when. Increase in disability among flight attendants. The pilot and speculative differences in the fume experience front to back.

Carbon monoxide in detail. Symptoms and their association with CO exposure levels.

Diagnosing carbon monoxide poisoning. TCP as an early suspected toxicant. The potentiality of NOx.

Era 2000 – 2019

Accounting, cabin sensors, culpability of regulators.

Conspiracy of Silence, Ethics, Morals,

Workers Compensation.

Options supporting total elimination. (of aerotoxic syndrome).

Attach #1

Root Cause

Airline industry response to competitive market forces.

  1. 2493 – The Airline Deregulation Act of 1978.

We have hinted at the roll of the U.S. 95th Congress having too hastily and with little foresight ratified the deregulation act. Why did Congress settle upon free enterprise as the savior of the airline industry?

The very first sentence of the Act states: “To amend the Federal Aviation Act of 1958, to encourage, develop, and attain an air transportation system which relies upon competitive market forces to determine the quality, variety, and price of air services, and for other purposes.” (Emphasis is mine.)

Competitive market forces”! All the rage in the 1970s, even Dr. Paul Samuelson, author of the primary text, “Economics”, fell into line with the popular interpretation that the very best economic outcome for all of society was to remove all government oversight from business enterprise. In this fashion the world’s economies could benefit from Scottish father of modern economics, Adam Smith, and his late 18th century theories. Smith’s still-influential work, “Wealth of Nations” (1)   states that regulations on commerce are ill-founded and counter-productive. He then explains the theory based upon his personal ethics and “moral sentiments”. He explains that when a businessman pursues his own self-interest (2) , An “invisible hand” acts to assure that everyone, including society, benefits.

The airline industry at deregulation

Ticket prices began to loosen somewhat and the when the CAB closed, fell drastically as the newly-released airlines began to compete. Revenue that had been available at CAB fares and that were set so as to finance and service debt and the costs of those regulated times. Then of a sudden the costs were there, but the revenue was no longer available. Nowhere in the deregulation literature are costs of airline operations mentioned. From lawmakers to executives, no one thought about it. For the air carrier executives it was swim or sink.

The airline deregulation act threw air carrier executives into a passionate obsession with corporate survival. From 1985 to deep into the 21st century, survival was the only option, the only goal. If we consider the histories of 24 air carriers from a 1970s list of major air carriers, we soon realize that five-sixths, 83%, failed through acquisitions, mergers, or liquidation. The last important merger, U.S. Airways (Survivor)/ American airlines (acquired), occurred in December 2013. Upon merging the victor, U.S. Airways, changed its name to American Airlines. Today only four (4) airlines from the old days survive. (3)

Reference, “The Good, the Bad, and the Ugly, 30 Years of US Airline Deregulation”, tells a portion of the story. (4) What this document does not mention is the Really Ugly. The Really Ugly (5) has evolved since CAB closure on 1/1/1985 – toxic air slowly began to enter occupied areas of airliner cabins where pilots and flight attendants spend their careers; where unsuspecting passengers enjoy low fares to travel.


The Airline Deregulation Act of 1978 imposed a very foreign environment upon air carrier executives. Micromanaged by Civil Aeronautics Board officials for 40 years, competition between carriers was forbidden. Airline executives had no experience with competition. They did suspect unfettered competition would reduce ticket prices, which was the one and only goal of U. S. lawmakers. They didn’t fully anticipate the aggression that would soon develop into a survival-of-the-fittest war on each other.

Zealously cutting costs in an effort to align expenses with depressed income from falling ticket sales they soon created balance sheets that were upside down . . .  cost over revenue . . .  expense over income. We cannot view these old profit and loss statements, but we can accurately understand why bankruptcies soared. One consequence was the necessity to avoid expensive engine overhauls. This created slow deterioration of engine oil seals. It was and remains a long-term process of unmitigated wear and tear that would create the cabin contamination problem.

How would members of the air transportation industry react:

Executives and Senior Managers:

  • Did not at first believe that oil leaks would occur in a way that could affect occupants inside the aircraft. They denied all allegations. Because of the curtain of silence, we can only surmise that manufacturer design and build personnel would have told them the truth. Assuming that carrier executives were truthfully briefed, that is where the truth stopped. That is where truth resides today.
  • Spin untruths (to deny, rebuff, deflect, falsely assert) that have and continue to be spoken in response to employee pleadings, workers compensation claims, and media fume reports.
  • Bewail when because of fumes a captain must divert to an airport short of destination. The cost: a spare airplane with crew, passenger inconvenience, crew injuries or illness, passenger illness, another landing fee, connecting flights missed or delayed. $$$$$$
    Some carrier managers are now prohibiting diversions. Their orders: fly to destinations; work through the fumes; fumes are not dangerous, if you feel ill it will soon pass.

Yes, fumes are dangerous. These kinds of procedures are dangerous.

On June 17th 2022 I received a report from a flight attendant saying that at her airline flight attendants are required to be at work regardless of whether they (a) have been made ill by fumes, (b) need time to recover from respiratory or neurological injuries from fumes, (c) have contracted Covid-19 and are ill from the virus. Failure to be at work flying their schedules results in punitive demerits on their employee record.


  • Do not wish to speak of the cabin fumes problem. Their jobs are their lives. As they age and grow experience, alternative employment options decline. Nearly all purchase loss of license insurance. More than a few file claims against this insurance from time to time. One airline captain specifically would not chat about fumes because, he said, “I’m afraid I’ll lose my job.
  • Some of them, defend their positions of responsibility as captains. They make inflight decisions, especially emergency decisions, according to their education, training, and experience with the risk. To them safety and health is paramount. Safety and health inflight is their responsibility and they accept it willingly.
  • Some captains, do as their employer demands. At one airline a senior management directive prohibited the flight crew from diverting to an airport short of destination. The assertion was that fumes are not dangerous. If illness results you will soon recover. Fly through it!

Serious health issues can result when (a) pilots are not told the truth about toxic cabin air, and (b) when directed to disregard a dangerous situation on an aircraft.

Flight attendants

normally love their job. The last three decades have not been normal. Today they:

  • fear being injured. Injured they need recovery time off, forfeiting wages. Injured by fumes, many are denied workers compensation benefits. Their “self-insured” employer has authority over compensability, which is a conflict of interest. The employer’s effort to support corporate profits, can impose debt upon the employee.
  • have shared with me their bankruptcy experiences. Some have become destitute and unable to continue to fly. Some resign without benefits.  Attachment 8 to this report will discuss workers compensation and the fraudulent cases being imposed upon airline employees.
  • are being intimidated by punitive demerits upon their work record. This is retribution, which is illegal under OSHA rules. The Memorandum of Understanding between the FAA and OSHA does not contribute to aviation health and flying safety. Among the work rules infractions are:
  1. i) Refusing to fly while ill or suffering from certain injuries.
  2. ii) Taking time off to recover from illness and injury from fume events. These periods of incapacitation can be short term, temporarily incapacitating, permanently disabling, and life threatening.

iii) allegedly, at some airlines flight attendants are required to work while positive for the Covid virus.

Working while ill from Covid-19 while also recovering from CO poisoning.

This allegation is new and unique. It must be researched as soon as possible. Unable to leave the environment a flight attendant exposed CO fumes, which by statements in the research literature could be in the air in small quantities at all times, plus currently active symptoms of Covid 19 in combination, is an exposure of serious concern.

Could it be extremely damaging to the lungs, hemoglobin, tissues, immune system health? A vaccine needs strong immune system support in the battle toward recovery. An anoxic circulatory system could neutralize or seriously inhibit the vaccine.

The FAA:

  • By supporting industry defenses against contaminated cabin air, the FAA is complicit. FAA authorities deny and generally dismiss toxic issues alleged in cabin air. The FAA and NTSB do not investigate incidents of cabin contamination.  **

But for the Memorandum of Understanding, 6) OSHA could investigate and would easily uncover the toxic problem on aircraft. The MOU prohibits OSHA from involving itself with any airline issue other than hazard communication, bloodborne pathogens, and occupational noise.

Silence prevails around all aspects cabin fumes both inside and outside of the industry.

** An incident confirms FAA and NTSB unwillingness to investigate:
The premise – Incidents are precursors of accidents as defined in the Federal Air Regulations. The FAA says it investigates “incidents’, but it does not.

U.S. airways flight 1041, January 16, 2010, the return leg of service between Charlotte and St Thomas, was the final leg of a three part schedule in the same aircraft. (7) The crew did not notice the insidious onset of fumes on the first two legs. We speculate at some physiological impairment as the cycles and flight hours increased.

Slight fumes were noticed just after departure St. Thomas. At cruise flight attendants noticed red eyes of both pilots. The pilots did not notice any flight deck odors. Unaware of fume incidents and feeling no illness, the pilots continued to destination. Upon descent and approach both pilots had become incapacitated. They could not discern the need for their ready and available oxygen. They managed somehow to land the aircraft at Charlotte without becoming unconscious. Both lost their medical certification. The captain took his own life six years later.

The event was reported to the FAA where it was assessed as an incident not requiring investigation. Only one crewmember among the seven ever returned to work. In 2017, upset by the FAA’s decision not to investigate, the crew petitioned the FAA to reconsider. Since the flight had nearly ended in catastrophe, they thought “incident” should be changed to “accident” and case investigated. The crew collected their recorded histories including health records. Senior FAA authorities invited the crew to present their case in person, which they proceeded to do.

The interview went well. Officials were to discuss their request, review the documents, and reply with their decision. Several months elapsed when they received their documentation returned unopened. No reply was ever made. No investigation was made. To this date, fume events have never been investigated.

Airline Ground Safety Departments

  • Appearance suggests that the old-time concept of a ground safety departments at each air carrier had faded away after deregulation. For certain, such a department with its professional safety manager would have been a drain on essential revenue; revenue the carriers could no longer muster.

Appearances again suggest that the safety departments that continued after deregulation are managed by employees selected from within; flight and ground safety being always independent from the other.

An Alliance

between the

  1. S. Department of Labor, Occupational Health and Safety Administration

and the

Airline Ground Safety Panel (AGSP)

Through the OSHA and AGSP Alliance, both organizations are committed to providing AGSP members and others with information, guidance, and access to training resources that will help them protect the health and safety of workers, particularly by: 1) reducing and preventing falls; 2) addressing issues related to small businesses, motor vehicles, and hazard communication; and 3) understanding the rights of workers and the responsibilities of employers under the Occupational Safety and Health Act (OSH Act).

Signed May 20, 2008; renewed October 10, 2012; and April 08, 2015; concluded April 24, 2018.

Apparently the airline industry saw a need once again in 2018 for ground safety. The airline Ground safety panel alliance with OSHA was concluded in 2018, now reinstated in 2022 – for two years. The alliance will concentrate on ground safety issues such as slips, trips, falls, ground equipment, and classification and labeling of chemicals. These are the usual sources of accidents that traditionally swell the frequency and severity statistical records in the airline industry.

However, no mention is made of help for flight attendants and the many occupational issues that occur while serving the airborne public. Airline executives for decades seem not to have been adequately concerned with the inflight, passenger cabin side of the business. Accident trends can be just as problematic up there as on the ground. Clearly OSHA still has not been granted access to the passenger cabin. The Memorandum of Understanding (MOU) between the FAA and OSHA blocks access to aircraft, firmly establishing and enforcing the barrier. Only the FAA has safety jurisdiction over the flight attendants in the passenger cabin. Since 1985, the FAA has done nothing significant to improve safety in aircraft cabins.

Cost cutting

Cost cutting qualifies within the ‘Fear’ category. Fear of failure to be sufficiently frugal and aggressive against cost was and to some degree remains a significant part of raw survival in the airline industry. In the beginning wages and benefits were drastically cut along with inflight services and other passenger comforts. So cornered by insufficient funds were some airline executives that they offered workers voluntary furloughs “for the good of the company”. Loyal flight attendants among others stepped up. My daughter served her employer without reward by taking a six-year voluntary furlough. Her sacrifice was a contribution to her employer, U.S. Airways, as it navigated its bankruptcy reorganization that began in August 2002. That sacrifice may also have helped American Airlines avoid bankruptcy, the only U.S. airline that did not file for court managed reorganization. (8)

Workers compensation insurance in the USA is governed under individual state oversight. This means that 50 different plans must be reviewed to understand how on-the-job injuries are addressed. Commercial insurance policies required by law at every airline were cancelled all at once in 1980. For years they had felt that relinquishing claim management to insurance companies, premium and claim auditing by outsiders, and our built-in 1% profit margin were not in their best interest. That decision by carrier management ended my one and only executive career path, so I guess I’m a victim of deregulation, too.

Those most hurt by abandoning commercial workers compensation were the employees. Flight attendants especially, all of whom receive no assistance to recover from carbon monoxide poisoning and other injuries that are no longer covered for medical and wage indemnity, must accept the cost on their own account. Work-related injuries, incurred and uncompensated at no fault of their own, employees are at risk of developing lifelong health problems.

(See Attachment 8 – Workers Compensation).

Perhaps the largest expense to be avoided or ignored by carrier executives is major maintenance of high cycle, high time engines, auxiliary power units (APUs), and the environmental control system (ECS) of aircraft. The cost of engine overhauls is seen as a big reason behind the onset of oil seal deterioration, oil leaks, and cabin fumes. It is the exact point where lack of lawmaker knowledge allowed this prohibitive situation to become established at the risk of human health and safety. Inadequate maintenance of APUs is a significant contributor to the problem. Some of our most debilitating injuries are caused by inadequately serviced and maintained APUs.

From 1994 to 2004, maintenance problems have contributed to 42% of fatal airline accidents in the United States. Maintenance-related accidents and incidents are caused by a breakdown of organizational processes, decisions and culture. (9)
(TBO –> EHM)** Maintenance operations are also affected by human input that shows up as weaknesses in organizational processes leading to

  • EHM and toxic cabin air has never been admitted by the airline industry. To admit and pay the cost of essential aircraft engine overhauls at as much as $3,000,000 each would be to disregard the Airline Deregulation Act’s low-fare goal. (JML)” v:shapes=”Text_x0020_Box_x0020_15″>Lack of motivation
  • Fatigue and stress
  • Time pressures
  • Misperception of hazards
  • Inadequate skills (10)

**  TBO –> EHM – Manufacturer recommended time since new or between overhauls, suspended in favor of, engine health management, condition based maintenance, and predictive protocols and no set hourly recommendations for maintenance.


(1) https://www.adamsmith.org/the-wealth-of-nations/

The Invisible Hand and the post-deregulation modernized airline industry.

(2) https://corporatefinanceinstitute.com/resources/knowledge/economics/what-is-invisible-       hand/

(3) https://www.airlines.org/dataset/u-s-airline-mergers-and-acquisitions/

(4)https://www.researchgate.net/publication/223075818_The_Good_the_Bad_and_the_Ugly_30_        Years_of_US_Airline_Deregulation

(5) “Hard Landing” by Thomas Petzinger, Jr., “The Epic Contest for Power and Profits the Plunged       the Airlines into Chaos”

(6) https://www.faa.gov/sites/faa.gov/files/about/initiatives/ashp/FAA_OSHA_MOU_2014.pdf

(7) https://avherald.com/h?article=425f6a41

(8) The Last Merger – “Twelve Years of Turbulence”, Gary Kennedy with Terry Maxon

The Inside Story of American Airlines Battle for Survival.

(9) Podcast https://hbswk.hbs.edu/item/cost-cutting-leads-to-turbulence-in-the-airline-        industry

(10) https://www.baumhedlundlaw.com/aviation-accident/why-planes-crash/aircraft-        maintenance-negligence/
(11) https://beyondphilosophy.com/cost-cutting-airlines-headed-trouble/

(12) ) https://beyondphilosophy.com/cost-cutting-airlines-headed-trouble/

https://www.fiixsoftware.com/maintenance-strategies/condition-based-            maintenance/

(13) https://www.poentetechnical.com/aircraft-maintenance/costs-reduce-in-aircraft-     maintenance/

CO Attach #2

Aircraft, Powerplants, Repair and Service

An Evolutionary Miscalculation

Leading to the

Proximate Cause of Contamination in Cabin Air.


Aircraft designers and engineers of the day were considering technical aspects of the world’s first airliner, the De Havilland Comet. As the storytellers at magazine “Flight International” would write, “the comet enjoys a great advantage over all other pressurized airliners.” (1)

This was a new concept aircraft intended for commercial passenger services. They were concerned about the cabin environment and its effect upon air travelers’ years into the future. Compressed air extracted from the engine compressor at 2000 C (3920 F) would be cooled, then sent through an air processing unit before entering the aircraft interior where occupants would find it comforting and pure for breathing.

Bleed air, it came to be known. Cheap and plentiful, it would assure rapid and affordable public transportation while flying over two-thirds of the earth’s atmospheric cocoon. The experience would be worry free for the air traveler.

Or would it? The air conditioning system was working very well. Designers, engineers, manufacturer and air carrier executives at the time had no definite reason to be concerned. But these technical experts appear to have been not entirely sure. As “Flight International” goes on to state: It was at one time feared that contamination of the compressor air within the engine might prove a problem, but this has fortunately proved unfounded. In the few cases where an engine oil leak has occurred, the affected engine has immediately been shut off from the air supply.”

 How did they know, “immediately”, that an oil leak had occurred? Had designers provided sensors that would alert the flight crew? Was the oil quantity gage of a vernier scale design? Why do not the aircrews of today have that information? Did oil leaks from our modern engines become so frequent that warning devices were removed?

For years the Comet and its successor aircraft operated to the best of this common-sense ideal without a hitch. Supported for safety by “engine manufacturer recommended time between overhaul (TBO) strongly suggesting turbine engines be overhauled each 5,000 hours of operation, seals, we presume, were regularly replaced. We suggest that by air carrier executive order, this was routinely accomplished. These were the years of airline dictatorial oversight by the Civil Aeronautics Board (CAB). All aircraft and engine maintenance costs would have been built into the ticket price formula and regularly paid. During the TBO era, which spanned the decades from 1938 to1978, no engine oil fumes of consequence leaked into areas inhabited by air travelers. We knew, then, of no civilian illnesses or injuries arising from chemical fumes or particulate matter.

The U.S. Air Force had some problems with fumes-related injuries, mostly related to the J-57 engine.

We cannot verify the truth of the previous statement; however, I was responsible for monitoring air carrier operations in support of workers compensation insurance programs. My employer, U. S. Aviation Underwriters, Inc., New York, N.Y., insured half of the major airlines of the day for hull insurance, liability insurance, and workers compensation. Reviewing current accident and incident cases throughout the 1970s, no cases of oil leakage into occupied areas of aircraft ever came to my attention. No claims were ever made to cover the cost of work related environmental illnesses. Jet engine fumes were everywhere. Passengers had to walk across the tarmac at many airports, but no official complaints were brought to insurance companies.

The same can be said about the other half of the industry. Our competitor’s workers compensation department manager was a friend, and we would have discussed cabin fumes if any had been rumored.

In addition, The Hartford and Travelers Insurance Companies employed a few aviation-savvy safety engineers. They provided field safety services to airlines (workers compensation) and airports (general liability) respectively. Neither brought any environmental complaints into our discussions.

The Proximate Cause of Contaminated Cabin Air

Engine Health Management

Manufacturers of aircraft and engines prepared for the revolutionary new industry in advance of deregulation. They appear to have been aware that the new model engines and airframes would be expensive to maintain. Multitudes of sensors were placed in and around the new low and high bypass turbofan engines destined for new models of highly reliable aircraft. The old engine TBO protocol in place since at least 1950 was discontinued. The engine health management scheme would provide maintenance only when necessary according to performance data recorded and transmitted by satellite to monitoring stations. Operators and manufacturers would have real time control over equipment efficiency into the future.

It should have been the best of all worlds. It is hardly arguable that these new jet engines are the most highly engineered and reliable mechanical tools ever built. But the original assumption about engine oil leaks remains. No one considered the value of TBO over Engine Health Management and Condition Based Maintenance. In fact, engine manufacturer sales departments had sold new engines at a premium discount expecting to recover some of their cost when they were returned for overhaul. Manufacturers were unaware that their airline clients would take advantage of removal of the 5,000 hour TBO protocol by operating engines continuously for 30,000, 40,000, and even more hours without significant maintenance. No one thought about deteriorating compressor bearing seals, oil leaks, and cabin contamination. (2)


As time passed and fumes became noticeable, the industry failed to have air quality sensors installed on aircraft. By then authorities must have been aware, yet associated internationally, they determined not to act. They apparently did not even investigate, or if they did investigate, they may have found the information too sensitive to follow-up.

They might have become “willfully ignorant”. For if they knew they would need to act: if any one country lawmaker, one airline official, one regulator, had acted responsibly, all would need to act responsibly.  They would need to act to protect their reputations and their dwindling market share.

Clearly, the courage to act ethically and morally to protect public and occupational health is insufficient throughout the industry.


Flying safety takes a back seat

A disturbing fact – Engine Health Management systems contain no sensors for engine oil leaks; no sensors for cabin fumes; no indications to warn pilots of toxic conditions aboard their aircraft; conditions that could threaten their health, the health of their cabin crew associates, and the health of their passengers.


  • (1) Flight International – 1 May 1953, pg. 554.  Air Conditioning – Ref. pdf. included https://www.flightglobal.com/pdfarchive/view/1953/1953%20-%200560.html – Located in Archives closed due to covid restrictions.
  • (2) https://www.reuters.com/article/us-air-show-engines-idUSBRE95F0F220130616
    But high reliability that has become industry standard is hampering that spare-part business. CFM said that CFM56 engines delivered nearly a decade ago were due to come in after six years but are just now coming in for service. The revenue is thus arriving later than predicted and a “bow wave” hasn’t materialized in the way it was expected.
    “We have a pretty substantial population of engines that are at around 40,000 hours” before their first shop visit, CFM spokeswoman Jamie Jewell said. In one case, an engine stayed on the wing 14 years before coming in for its first major repairs.   While that affects CFM’s revenue, it is doubtless appealing to airlines.

General references:

Engine cost and reliability –
a)  https://www.fiixsoftware.com/maintenance-strategies/condition-based-maintenance/
Fatigue or uniform wear failures are not easily detected with CBM measurements
b) https://run.unl.pt/bitstream/10362/8792/3/TEGI0308.pdf

  1. c) https://www.scribd.com/document/388464482/2576825
    Aircraft Scheduled Airframe Maintenance and Downtime Integrated Cost Model Table 2

Typical maintenance check intervals for different aircraft types, adapted from Eurocontrol [4]. Multiple sources, including Aircraft Technology Engineering & Maintenance, Aircraft Commerce and Boeing AERO.

A typical fume event

As I write this on 20 June 2022, a 17 June 2022 report arrived of an Allegiant Airlines Airbus 320 flying from Orlando to Tulsa having a fume event.

Fumes allegedly entered the cabin as the pilot reduced power for descent from cruise altitude. This is common. Reducing power causes a change in sealing air pressure in the #1 compressor bearing sump. The sump, or bearing compartment is where hot, pyrolyzed oil first encounters oxygen. As they mix a process of combustion begins. The encounter is rapid, a matter of seconds before the air is vented out of the sump toward the internal oil separator.

But now with sealing air pressure remaining low during descent, products of partial combustion of the hydrocarbons that make up the total volume of oil produce carbon monoxide (CO). instead of being vented internally, a portion of the CO leaks out through the bearing seals and into the compressor stream of new air. A portion of that CO in compressor air is then bled off for use in the cabin. The flight attendants began to feel ill, coughing continuously. Passengers too must have been affected. Emergency medical responders with respirators boarded that aircraft to begin treating those affected.

About this Airbus, the Allegiant fleet operates fifteen A320-200 aircraft. The list does not show a registration N230NV. It does show an N203NV.

N203NV was delivered to Allegiant in November 2021. The aircraft is posted to be 9.6 years old. Its first flight was on 9/11/2012. It had a private owner apparently in Singapore, was traded to Spirit Airlines in 2021 but never delivered. Stored under its Singapore registration from January 2021, it apparently sat idle during the pandemic for 10 or 11 months.

No information is available about the private owner in Singapore or about logged engine hours. The engines are likely to be original. Also likely to never have been overhauled. How effective was the post storage maintenance service? How long have oil fumes been leaking?

The event as reported by Avherald:

Accident: Allegiant A320 at Tulsa on Jun 17th 2022, fumes on board

By Simon Hradecky, created Monday, Jun 20th 2022 16:00Z, last updated Monday, Jun 20th 2022 16:00Z                     https://avherald.com/h?article=4fa8b79b&opt=0

An Allegiant Airbus A320-200, registration N230NV performing flight G4-2397 from Orlando Sanford,FL to Tulsa,OK (USA), was on approach to Tulsa when flight attendants noticed an odour and began to feel unwell. The flight crew, while maintaining routine communication, continued for a safe landing on Tulsa’s runway 18L.

Passengers waiting for the return flight reported that after the aircraft arrived at the gate suddenly emergency services surrounded the aircraft, emergency responders with respirators arrived and boarded the aircraft. The emergency responders were told that during the descent the flight attendants had become ill and coughed excessively. The return flight was cancelled.

Tulsa Airport reported their fire department responded to a call when Allegiant flight attendants felt ill after reporting an odour on board of the aircraft. No hazardous substances were found on board of the aircraft.


Attach 3          Carbon Monoxide – how it forms in aircraft engines

                                    An assertion without an alternative.


Carbon monoxide (CO) is a poison. It kills and disables more people than any other toxic compound. It is the most studied. As long as a victim’s feet are on the ground, someone, somewhere has studied it. Peer reviewed literature addresses every instance of its occurrence from every angle imaginable. But once a person leaves the ground as, perhaps on an airplane, the literature stops. No information at all exists to help us understand the why and how of CO at high flying altitudes. We must sort it out for ourselves.

CO poisoning hypoxic. 1 Affinity of red blood cells (hemoglobin) to bind with CO is about 240 times stronger than that for oxygen (O2). When a person becomes surrounded and breathes into the lungs the odorless, tasteless and colorless fumes, O2, which is also inhaled is shunted aside in favor of CO. Until the victim escapes the toxic environment, blood carries the poison throughout the body depositing it in skeletal muscle tissues, organs, especially the heart muscle, and the nervous system, especially the brain.

When the flight attendant closes the door on a commercial airliner prior to departure, the aircraft becomes an air conditioned pressure vessel. Arguably, clean air can be expected on most flights; it is, after all, the #1 requirement for an enjoyable trip. Thirty years of experiences reported by crewmembers and passengers confirm that clean air is not always available.

How Is Carbon Monoxide Produced in aircraft?

Until now, investigators from outside of the airline industry have never written about production of CO on aircraft nor contemplated how it can occur. If engineers within the industry have investigated this phenomenon, they retain the data as proprietary. They and their mangers also do not act to bring the process under control. Complete combustion of flammable carbonaceous material gives non-toxic carbon dioxide and water. When internal temperatures are high enough to begin the combustion process but not high enough to assure complete combustion, CO is formed.

Production of CO

Two units exist on aircraft where CO can be produced: the auxiliary power unit and the engines. Within each unit there are two areas where the process can occur:

  • (1) The wing mounted engines – Please see video explaining how bleed air works and how contaminants from engine oil can invade the cabin. Link: “Bleed Air System Explained”. 2
  • (2) The tail mounted auxiliary power unit 3

The APU is a turbine engine driven system that uses the same oil and supplies compressed air in much the same fashion as the main engines. The APU is used primarily on the ground to provide air conditioning, electric power, and compressed air for starting the engines. High above the tarmac, the APU is unhandy for regular maintenance inspection. When uninspected for extended periods of time oil leaks can occur unnoticed. Ducting leading from the APU into the main distribution duct can become fouled. When this occurs, which may be more common than we know, oil residue including contaminants can continue to taint cabin air while airborne. Whether this type of contamination includes carbon monoxide gas is unknown.

Our investigations discovered many serious illnesses caused by faulty APUs. Some of them are listed in the testimonials from aircrew.

Creation of carbon monoxide in turbine engines

Where is the point of CO generation and how does it occur:

Sealing air first contacts oil in the bearing compartments (sumps). This is the first and best opportunity to produce carbon monoxide.

Bearings support the rotating stages of the and the turbines. Although the seals located throughout the engines can wear, crack, fail, and leak oil, we are concerned only with the foremost bearing sump of the forward-located compressor section. This sump is closest to the air intake upstream from the bleed valves. This is the bearing section where sump air seal integrity is essential. (See CFM engine schematic in this section.)

Oil exists for the sole purposes of lubricating and removing heat from the few mechanical parts of the engine. The sumps contain the highest temperatures and pressures in the engine except for the combustion section itself.

The Engine Lubricating System

In this schematic, imagine a molecule of oil as it travels from the bottom of the oil tank through the amber route through the oil pump and supply filter directly to the compressor bearings, turbine bearings, and the accessory gearbox – the light brown oil lines to the blue inside the engine silhouette. After the lubricating job is done, oil is scavenged through boost pumps, a filter, the fuel/oil heat exchanger and back to the reservoir.

Bearing sump schematic.

Oil is sprayed through the oil jet directly onto the spinning roller and ball bearings that support the rotating core shaft. Temperatures are said to be less that 17000 C in this, the #1, or front bearing compartment or sump. Oil temperature approximates continuous 2180 C. Sealing air, shown at point X in this schematic, will be the heat of compression temperature at the 5th stage bleed valve, about midway along the 9 stage compressor, assuming the CFM 56 engine. The inward moving air meeting the spraying oil in the bearing inner compartment establishes the first and best point where combustion of carbon material can occur. Considering the constant, very dynamic environment here, combustion time will be very short. Weighing the combined temperatures of bearing sump, oil spray, sealing air and the seconds available for combustion before air is vented out the top of the sump and oil is scavenged from the bottom, production of carbon monoxide would seem to be reasonably good. 4

We have followed the oil to this point in the forward compressor bearing sump. Here is where seal integrity counts the most. When seal wear, deterioration, and the occasional failure occurs as the seal fails or is utilized beyond its designed useful life, we can imagine carbon monoxide gas forming by incomplete combustion in the high heat located here. The gas can then leak outward through the four banks of labyrinth and face seals into the plenum area outside of the sump. We might also imagine oil sliding upstream of air entering the inner sump compartment when the pilot reduces power at top of descent. We are told this happens but we have no visible evidence.

Once outside of the sump, gas laden air will exit the plenum and enter the compressor airstream, which speeds aft as it is compressed to supply hot compressed air for the burner section and production of thrust.

CFM 56 high bypass turbine engine.

Visualizing the above narrative, number 1 compressor bearing is located on the left in the schematic below. The plenum (empty compartment) is shown above and before the #1 bearing. Carbon monoxide gas will enter the empty plenum and escape from between the compressor rotor disks into the front stages of the compressor air stream. This airstream is flowing very fast, accelerating and compressing through the 9 stage compressor. From the location of the first four, low pressure compressor stages (hash lined blades) to the intermediate, 5th stage, bleed valve located half-way through the high pressure compressor stages, some of the CO must cross the gap from the inside diameter of the compressor core to the outside diameter, shroud, where the bleed valves are located.

Some of the contaminants, including carbon monoxide gas, will complete the crossing at the 5th stage bleed valve. We are solidly assured that enough CO gas does cross the airstream to be extracted through the bleed valve. Once extracted, the route to the cabin and flight deck is assured. Cabin occupant exposure to CO gas will be assured.

Passage of CO from the 5th stage (at cruise) and the 5th plus 9th stage (from top of descent to approach altitude) for landing.

Bleed air enters through the 5th stage bleed valve at “I”. This valve serves the cabin’s need for pressurization throughout taxi, takeoff, and cruise. When at top of descent when the pilot reduces power to start downward for landing, the compressor section spools down to a slower RPM. 5th stage bleed air becomes insufficient for cabin pressurization needs. The 9th stage bleed air valve then opens automatically to supplement 5th stage air. The ninth stage bleed stays open until power is added to level off at approach altitude in preparation for landing.

We can infer that when both the 5th and 9th stage bleed valves open, more CO can be extracted than through the 5th stage alone. This inference is supported by reports and testimonials of fumes becoming noticeable at top of descent with increasing inability of flight attendants to accomplish prelanding preparations. Several cases of pilot incapacitation are recorded from this actual occurrence. Threat of pilot incapacitation from odorless CO as the aircraft approaches ground level must be seriously contemplated as the airline industry considers how to cope with the carbon monoxide hazard on aircraft.


  • (1) Hypoxia / Anoxia – what is the difference? MedicineNet
    By this definition, with carbon monoxide we are dealing with hypoxia.
  • (2) Bleed Air Explained – You Tube

(3) What do auxiliary power units (APUs) do on aircraft?

(4)  Is a Cumulative Exposure to a Background Aerosol of Nanopar­ticles Part of the Causal                Mechanism of Aerotoxic Syndrome? PDF

Carbon monoxide poisoning

Introduction 1

At present, carbon monoxide (CO) poisoning remains a leading cause of unintentional poisoning worldwide [1]. In Italy, the estimated incidence is about 6.000 cases per year, resulting in more than 350 deaths per year [2]. The clinical symptoms range from headache and confusion to coma and death, with mortality rates reaching up to 3%. CO is a nonirritant gas generated during the incomplete combustion of carbon-based compounds. Upon exposure, CO binds to hemoglobin with an affinity known to be 200-300 times greater than oxygen, generating carboxyhemoglobin (COHb). It decreases both the oxygen carrying and oxygen-delivery capacity of blood, inducing tissue hypoxia (COHb) theory) [3]. While the hypoxemic hypoxia suggested by the COHb theory is undoubtedly a key component of CO poisoning mechanisms, it is not enough to account for some of the neuropathological manifestations of CO poisoning. In recent years, researchers have demonstrated CO interaction with soluble guanylate cyclase, ion channels, nitric oxide, nitric oxide synthase, mitochondria, cytochromes, NAPDH oxidase, and xanthine oxidase. Direct effects of CO poisoning on separate organ systems are well explained by these extra-hemoglobin effects, with the most important being the effects upon nitric oxide and on reactive oxygen species (ROS). In addition, a direct effect on cardiac ion channels has been established [4].

General symptoms

Symptoms immediate during fume exposureSymptoms long-term or chronic






cognitive impairment (2)

tremor (2)

motor function (2)



high blood pressure


loss of equilibrium

rapid heartbeat

red eyes

seizures (2)


Death incl. suicide

Immediate symptoms plus:

memory loss

sensory deficits

vision disorder



Parkinsonism & essential tremor

nerve demyelination

muscle pain


emotion unstable

mentally unstable

shallow breathing

muscle spasm




(2)    CO competes with O2 in the lungs; at affinity 210 + times stronger than O2 . In a standard atmosphere of 21% oxygen and .1% CO, the blood will leave the lungs at 50% saturated with oxyhemoglobin and 50% saturated with carboxyhemoglobin. 2
This chart of carbon monoxide symptoms was garnered both from many peer reviewed documents and also verified with and augmented by personal interviews with ill and disabled crewmembers.

Carbon monoxide is called “the great imitator”. Among a long list of symptoms, it can manifest as symptoms resembling:


Angina – chest tightness, pain, palpitations

Fatigue – chronic fatigue syndrome


Parkinson’s disease-like tremors

Epilepsy-like muscle twitching and seizures

Concussion – chronic traumatic encephalopathy

Mountain sickness

Jet lag disorder – jet lag 3
Evidence suggests that disturbed circadian rhythms may not always be the cause. Reports from Bleed-free B787 travelers after long flights compare very favorably against reports from similar flights in bleed aspirated aircraft. San Francisco to Sydney – three days recovery seems usual after flights in conventional ECS environments. Bleed free evidence suggests arrival feeling fresh with little or no perceived fatigue. Reference: my daughter’s & son-in -law’s flight to Sydney, Australia, plus other incidental comments.

Hydrocarbons make up the full complement of synthetic engine oil. When present, an acrid odor offers a warning, not a timely warning, but incentive for the captain to act. By refusing to install CO sensors on aircraft pilots must rely on human olfactory evidence, the sense of smell, to advise of problems pending. Odorless early exposure cannot be sensed making the pilot vulnerable to the insidious onset of unconsciousness and his job significantly more difficult.

How often do aircraft fume events occur?

Engine time on wing

Common sense suggests that fume events will vary directly with engine time on wing since new or since major overhaul (SMOH), and the apparent lengthy time between critical inspection of APU performance. We have shown in our lead document (Anatomy of an Occupational Hazard) how the larger, more sophisticated engines of today remain on wing over periods of 20,000, 30,000, 40,000 hours or more before transmitted sensor data tells maintenance that overhaul is needed.

Fumes can be generated by any engine at any time, even new engines. Without access to aircraft logbooks or maintenance records, we cannot assure that more fumes events happen more frequently on high time engines. We challenge regulators and carrier managers to correlate fume-incident records with engine time SMOH. If found to be true, preventive maintenance on high time engines should emphasize the trend and replace bearing seals as fleet performance dictates.

No one knows for sure the frequency and severity of toxic conditions on aircraft. We do know that crewmembers, especially flight attendants, become ill and injured every day. Passengers too. Should we accept carbon monoxide exposure as part of air transportation service; a cost of doing business? That decision is left to you. Although the FAA and other regulators require contamination to be reported, it is mostly not reported. Regulators neither enforce the requirement nor maintain records of cases that are reported. This encourages us to speculate:

(a) Concentration of contamination

  • Small oil leaks cause mild, low level fumes undetectable by smell.
    Reportedly, seal designers say that a small amount of leakage oil is designed into the seal to extend seal life. 4 Seals leak a small amount always, they say. Age related deterioration and loss of designed tolerances of seals can be expected to cause leakage, increased evidence of contamination to be sensed, and the threat of low-level accumulation of CO in cell myoglobin (“cell hemoglobin”), which can result in muscle dysfunction. Tremors can result in tissues; the heart muscle; the brain.
  • Chronically weakened immune systems can lead to multiple chemical sensitivity. Flight attendants are candidates for MCS.
  • Repeated low level exposure to fumes can lead to accumulation of CO in blood and tissues of crew and passengers that increase throughout a crew duty day, or over several days in the same aircraft.5,
  • Moderate oil leaks may be steady or come and go throughout a flight.
    Pilots can become concerned when fumes are first reported, then concerned but wary as fumes clear away, only to return later in a flight. They may try to isolate the offending engine by deselecting one bleed air source then the other to learn if the condition ceases. Confusion and uncertainty can last for an entire flight.
  • Fumes may be constant and build throughout a flight. When over water or when pilots do not divert to emergency landing, unhealthy exposure to crew and passengers increases. Entire crews of flight attendants have been seen to become incapacitated, unable to rise.

6, 7

  • Continuous exposure throughout a flight can result in pilot incapacitation at landing. This possibility increases when the pilot reduces power to begin the descent for landing. Sealing air pressure in the engine bearing sump may reduce. Oil pressure in sumps remain the same. We suggest this might cause increase of CO production and leakage as less oxygen is available to produce complete combustion, plus the possibility that effectiveness of air seals decline allowing more fumes to pass through the seal.
  • Moderate to heavy smoke and fumes in the cabin and flight deck.
    Without question, this occurrence is caused by a seriously impaired seal.  Inflight emergency procedures should begin. Land as soon as possible is the one and only proper response.
    As with all levels of toxic exposure, emergency medical personnel must be requested before landing. All affected aircraft occupants must be treated with oxygen or bear the risk of long term illness or disability; common consequences of untreated CO poisoning.

(b) To what comparative degree are occupants affected?

  • Flight attendants:

Evidence confirms that flight attendants are far more susceptible to cabin fumes than all other occupants. Up and working throughout a flight, attending to passengers needs and desires, flight attendants breathe the most cabin air. When contaminants are present, especially carbon monoxide, they are by far the most affected. They display symptoms readily: mild headache and dizziness to falling unconscious in the isle. Headache, nausea, dizziness, trouble breathing, tremors for weeks and months afterward.

  • Pilots:

Similarly, pilots remain immobile for most of the flight. They are working, however, and may endure strains that impose some mild but increased respiration. Contrary to some industry suggestions, pilots do not panic; they do not hyperventilate.

Pilots have immediate access to aviator’s breathing oxygen, which they use throughout a fight if necessary.

  • Passengers:
    Passengers are relatively the most relaxed among aircraft occupants. They read, use electronic devices, sleep. They respire the least among occupants and by remaining relaxed will be least affected by fumes.

An historical perspective. Insurance data forgone.

In the 1970s, before deregulation and airline cancelation of commercial workers compensation policies, insurance companies maintained accurate records of all incidents, accidents, and claims made of on-the-job injuries. It was required by state law. Statistics were built around this data. I used the data to identify accident trends to be used in our airline accident prevention programs. That data is now 100% lost to the public. Comprehensive industry-level accident prevention data is unavailable today.

Concentration of carbon monoxide as altitude increases.

No research above that equivalent to the last camp on Mount McKinley is available to help. Evidence suggests greater concentrations of CO as altitude, and, incidentally, reduced partial pressure of oxygen in air increases as height above sea level increases. CO is generated in engines in the front bearing sump on the compressor section. Cabin altitude of the aircraft does not affect the process. Temperatures here will approximate less than 1,7000 C near the bearing in the sump, steady oil temperatures 2180 C, and generally, the adiabatic lapse rate. These high, medium, and low temperatures in combination conceivably could combine to create just the right environment for large amounts of carbon monoxide, only some of which are syphoned through the bleed air valves and into the ECS system.4

Some additional CO might occur from heat of compression in the early stages of the compressor, but the likelihood is not firmly understood.

We would like to theorize what could happen as man breaks from the bounds of earth, but il-equipped and without sufficient parameters of CO concentration, internal bearing sump temperatures, and a scale of altitude partial pressures to work with, we stand on positive speculation that the risk of CO is actually greater as altitude increases. 8, 9, 10, 11


General reference – every subject – “Carbon Monoxide Toxicity”, David G. Penney, Editor

  • (1) CO IDNS.pdf – A Case of Carbon Monoxide-Induced Delayed Neurological Sequelae Successfully Treated with Hyperbaric Oxygen Therapy, N-Acetylcysteine, and Glucocorticoids: Clinical and Neuroimaging Follow-Up
  • (2) “Carbon Monoxide Poisoning” – https://patient.info/doctor/carbon-monoxide-poisoning-pro,
  • (3) Jet Lag Disorder:  https://www.mayoclinic.org/diseases-conditions/jet-lag/symptoms-causes/syc-20374027
  • (4) “Is a Cumulative Exposure to a Background Aerosol of Nanoparticles Part of the Causal Mechanism of Aerotoxic Syndrome?” Howard, Johnson, Michaelis, & Co.
  • (5) S. Airways flight 1041, January 16, 2010 – Summary at appendix hereto.
  • (6) NWA SFO Narita – Summary at appendix hereto.
  • (7) XLA120 – Summary at appendix hereto.
  • (8) “Carbon Monoxide Toxicity at High Altitude”- ResearchGate, Wilderness and Environmental Medicine
  • (9) “Alveolar O2 and Altitude” – PFT Blog
  • (10)“Physiological Hazards of Flight ate High Altitude” – Pilmanis, USAF Research Laboratory.
  • (11)https://www.nfpa.org/-/media/Files/News-and-Research/Fire-statistics-and-reports/Detection%20and-signaling/RFImpactAltitudeCOToxicology.ashx


Recognize that these accounts of fume events are happening at all airlines

and in all makes and models of aircraft that rely on bleed air

for air conditioning and pressurization.

Summaries of Testimonials pertinent to this document.

Note: These fume event cases occurred as the progressive deterioration of engine and APU compressor bearing seals wore on since deregulation and cessation of CAB oversight of the airline industry. Aircrews were unaware what was happening. They were not prepared to recognize toxic fumes or possible sources. Everyone was confused, it would appear true also for regulators and carrier personnel, including maintenance and pilots. Manufacturer awareness is suspected but not confirmed. Much time had passed.

(5) U.S. Airways Flight 1041, January 16, 2010 – Source Avherald – From court documents.

Flight departed Philadelphia for Charlotte. Next sector flight departed CLT for St Thomas, Virgin Islands. Both flights apparently uneventful. On return, STT – CLT, fumes were noticed shortly after takeoff. Headache, nausea symptoms among cabin crew. During cruise altitude, flight attendant entered flight deck with refreshments noticing also pilots both had red eyes. Puzzled, pilots now recognized slight headache, sore throat, neck stiffness. Flight attendants report “random”, slightly acrid, dirty socks odor in cabin. Over duration of flight no noticeable odor occurred on flight deck.

Pilots recall feeling fatigue, woozy, groggy. Pilots sent message to dispatch requesting medical examination for crew upon landing.

From personal discussion with pilot, my interpretation of the approach and landing, J.M.Lind:  During descent, pilot capabilities deteriorated. Unaware pf their illness and together through mutual assistance they were able to land, apparently fighting against unrecognizable, pending unconsciousness. After landing, both pilots needed assistance to rise from their seats. Strapped onto gurneys they went by ambulance to emergency hospital services. Flight attendants also went for emergency medical help.

Medical examination. All suffering headache, nausea, etc. crewmembers were placed on oxygen for 2.5 hours after which they all received COHb tests. Results showed elevated CO among every member of the crew. Symptoms lasted for more than a week. Pilot neurological performance remained substandard for years afterward; both pilot medical qualifications were cancelled. First officer could not differentiate among highway signs and signals for a long time post-event and could not safely drive a car. All flight attendants became seriously disabled. Only one returned to work. Both the first officer and the returning flight attendant have become important friends in the aerotoxic battle.

Passengers were also ill. Separated from crew for medical help, almost no information is available. One nurse remained in contact with crew. Doctors at her hospital of affiliation were unable to diagnose her illness. Upon contacting the airline for details of what happened on the aircraft, airline authorities declined to cooperate. The doctors insisted. Authorities relented only after all attending medical personnel had signed non-disclosure agreements. At that point, crew contact with the nurse ended. Aerotoxic syndrome retreated behind the airline industry conspiracy of silence.

(6) NWA, B-747, SFO – NRT – December 2000. Aircraft not airworthy because of oil leaks. Four trans-Pacific flights, fumes repeatedly, illness, failing ozone converters.

Pilots write-up fumes and ozone converters. Converters changed on third flight. R=Engine oil leaks are not repaired. Line maintenance foremen refused to release aircraft. Management signed off. Maintenance foreman advised all passengers and crew drink much water. All passengers plus children very sick during flight. Reporting flight attendant’s second flight on this aircraft, became badly injured, disabled, never able to resume work. Now has multiple chemical sensitivity (MCS). Other flight attendants ill, subsequent condition unknown.
Notable: Normal useful life of ozone converters is 11 years – many thousand hours. When oil is present in bleed air, ozone converters fail in 4 hours. This happened twice in 4 consecutive cycles on this aircraft.

Reporting flight attendant’s symptoms became chronic; multiple chemical sensitivity.

No oxygen services offered or taken.

(7) XLA120 – 1 February 2007 Gatwick, UK – Orlando, USA

Twenty – forty passengers seriously ill. Acrid dirty sock smell. Symptoms severe headache, nausea, incontinence, skin blisters, extreme fatigue, and more. Long legal battle results in

2017 among passengers – Long-term, chronic symptoms: severe respiratory and neuronal, memory loss, insomnia, fatigue, mood swings, cognitive difficulties, joint/limb pains.

Narrative:           Mrs Samantha Sabatino and her family flew from London to Florida in February 2007. During the flight some 40 passengers became ill, including herself and three members of her family. Upon arrival to Florida she was hospitalised suffering from wheezing and crackles in her chest. No infection or viruses were found either in Florida or upon her return home. Her family were still experiencing ill health including violent nausea, stomach cramps, blisters on arms and hands, chest pain, severe headaches, vertigo, insomnia and loss of balance. She had complained to the carrier, XL Airways, who had denied that other passengers had complained of ill health. The Environmental Health Department have not carried out an investigation into the issue. She received unsatisfactory replies from the Health Protection Agency, the CAA and the Air Transport Users Council. She complained of being swept aside and questioned the effectiveness of these organisations.


  • (1) 2007 HOUSE OF LORDS Science and Technology Committee 1st Report of Session
  • (2) 2007 Documentary film: ‘Welcome aboard toxic airlines’.
  • (3) 21 April 2008 BBC Panorama ‘Something in the air’.
  • (4) 3 May 2010 Stewarts Law legal case – ‘Great victory’.
  • (5) 13 December 2013 ABC Australia 60 minutes ‘Toxic Flyer’

Full details of Flight XLA120 can be seen at the end of this paper under ‘References’.


Recovering from carbon monoxide poisoning. 1

Crew members usually do not have access to oxygen after landing. When ill they need medical help immediately. They may be transported via ambulance to emergency facilities, their employer may agree to send them, or they pay their own way after employers refuse to help. These incidents cause delayed access to emergency help during which time CO resides in blood and tissues. It flushes from the body at the half-life rate of 4 to 5 hours whole breathing ambient air. Depending upon

  • concentration level,
  • time exposed while remaining airborne, and the
  • depth of saturation of myoglobin in muscle tissue,

enhanced invasion of tissues as predicted by increased exposure factors at altitude, detoxification recovery time after landing can be lengthy.

From reference (1)
“The treatment of CO poisoning rests on the rapid restoration of oxygenation to bodily organs. The elimination half-life of CO is 4 to 5 hours; however, with the administration of 100% O2 via a tight-fitting face mask at normal atmospheric pressure, the half-life can be reduced to 1 hour.4 Use of 100% O2 increases the conversion of COHb and carboxymyoglobin to hemoglobin and myoglobin, thus increasing the oxygen saturation of the plasma and the end-organs.17

Lack of oxygen treatment and delayed detoxification response after landing will assure increased injury among affected aircraft occupants! Any extended time lag in the effort to locate and deliver 100% oxygen treatment cannot be tolerated.

Education and training for medical personnel at all levels:

Exposure of air travelers to carbon monoxide in the pressure vessel of an aircraft is a threat never before contemplated. It is unique, has never been investigated, and is neither understood nor recognized by healthcare personnel at any level. This imperative is included as prerequisite to this request for recognition and response by medical emergency and recovery healthcare personnel.

The Center for Disease Control has been kept informed of our effort to prevent injury from airline exposure to carbon monoxide. They will have a copy of this presentation. If they wish, we will try to work with them to provide a standard for all airline employees and passengers to guide the service when they arrive at any airport that has available resources. 2

Acute Care Testing

Effects of Carboxyhemoglobin (COHB)

Saturation in blood (%) with associated symptoms


In-blood %



No appreciable effect except shortness of breath on vigorous exertion, possible tightness across forehead
20Shortness of breath on moderate exertion, occasional headache
30Headache, easily fatigued, judgement disturbed, dizziness, dimness of vision
40 – 50Headache, confusion, fainting, collapse

60 – 70

Unconsciousness, convulsions, respiratory failure, death if exposure continues
80Immediately fatal

Half-life Scale 3

  • Elimination half-life of CO is 4 to 5 hours breathing ambient air,
    Breathing 100% oxygen, half-life is lowered to about 1 hour,

100% hyperbaric oxygen at 2.5 atmospheres reduces half-life to about 20 minutes.

  • In addition to restoring tissue oxygenation, hyperbaric oxygen therapy appears to:
  1. i) Improve cell function,
  2. ii) Alter CO induced inflammation,
  • iii) Reduce brain damage after oxygenated blood supply returns to normal.
  • If here is evidence of severe CO poisoning all patients may be at risk of subsequent development of long-term neuropsychological sequelae. They should be treated aggressively with hyperbaric oxygen.

Options for access to oxygen after-landing – emergency basis. 4

The airport locale will be the first reasonable option for urgent access to oxygen. Minimum service availability must include:

  • Facility within the terminal or adjacent thereto. Transportation to a remote facility wastes precious time and threatens increased tightness and depth of CO binding within muscle, heart, and brain tissues. At deplaning from the flight, access to oxygen is urgent for all who are affected.
  • Until permanent facilities are established, local emergency responders could set up temporary mobile triages to treat victims. Access to temporary triage should be as close as possible to the disembarkation point to assure rapid access and to minimize public awareness of an emergency in progress.
  • Since the urgency is acute, other options requiring any delay are not suggested.

Testing for carbon monoxide  in the process of identifying and evaluating need for oxygen treatment.

(1)    Test options:

  • (a) Invasive COHb testing is best left with those qualified to do so.
  • (b) Pulse CO oximeter 5– Pulse CO-oximeters estimate carboxyhemoglobin with a non-invasive finger clip similar to a pulse oximeter.
  • (c) CO breath monitor 6 – device similar to an alcohol breathalyzer.

Very little is written about carbon monoxide in the breath, however. Units are designed for anti-smoking treatment and for workers in industrial environments.

  • (2) Oxygen facilities affording both normobaric and hyperbaric treatment options as required.
  • (3) Records must be maintained to develop statistical data for risk evaluation purposes as well as fair and accurate cost allocation.
  • (4) (eCO) – exhaled carbon monoxide. (From an internet source.)

The eCO levels in exhaled breath are most commonly measured with electrochemical (chemiluminescence) technology [24, 7476]. The values thus obtained correlate with parallel gas chromatographic analysis and these sensors are sensitive in the 1-500 ppm range. Current analytical devices are portable which makes them ideal for clinical use [77]. More recent CO detection systems suitable for clinical measurements include a gas sensor adapted from a controlled potential electrolysis method, which is sensitive to 0.1 ppm [77]. At the experimental stage, several novel techniques based on infrared laser spectroscopic methods have been recently developed which report enhanced sensitivity for CO in the parts per billion (ppb) range. Variations on these techniques include cavity leak out spectroscopy (CALOS), integrated cavity output spectroscopy (ICOS), cavity ring-down spectroscopy (CRDS) and quantum cascade laser absorption spectroscopy (QCLAS) [7884].


  • (1) Complications of Carbon Monoxide Poisoning: A Case Discussion and Review of the Literature. gov
  • (2) Carbon Monoxide Poisoning Prevention Clinical Education (Web On Demand) CDC webcast.
  • (3) Internet Book of Critical Care. Carbon Monoxide Poisoning
  • (4) Causes and clinical significance of increased carboxyhemoglobin. Higgins, Acute Care Testing
  • (5) What is the role of pulse oximetry and carbon monoxide (CO)-oximetry in the workup of smoke inhalation injury? Medscape 2021.
  • (6) Why a carbon monoxide test is an essential part of a GP and practice nurse’s kit, Noel Baxter

Attach 6

Workers Compensation

In the airline industry


The airline industry with its lack of financial flexibility due to anemic revenue opportunities imposed by low airfares has been forced to downgrade issues of health, safety, and certain important maintenance functions. Dependability of modern equipment plus crewmember and maintenance professionalism to a considerable degree have combined to avoid catastrophes. Beyond that, stress from hazardous jobs, cabin fumes, and punitive rules of conduct exists in day-to-day operations.

We find deregulation to be the causative background. Deregulation removed oversight and imposed a style of survivalist competition that too often shortcuts reasonable business decisions. A large and vibrant industry, demanding ever-evolving sophisticated equipment, indispensable but expensive maintenance routines, depending upon highly trained professional aircrews and mechanics, high costs of fuel and supporting services, susceptible to many day-to-day operational uncertainties in service to the public, cannot be left to the corporate managerial staff alone. Across the scope of air transportation services, oversight is the missing factor that antagonizes the deregulation experiment.

This article examines:

  • Airline workers compensation
  • Accidents and Incidents left uninvestigated
  • Employees injured and poorly served by a hijacked work-injury indemnity system.
  • Conflict of interest
  • Punitive incentives.

By the time this document has presented the story, perhaps a seed of responsible action will have been planted. We are here to expound further, and to assist as necessary.


Airline operations present risks of loss that exceed those found in the usual commercial business environment. One insurance company’s financial capacity to provide insurance to cover an airline’s exposure is insufficient. As the aviation industry grew after World War I and prospects for a role in public service became apparent, entrepreneurs formed two managing general agencies (MGAs) each with a membership of several general insurance companies. These companies dedicated a portion of their established underwriting capacity which, when added to the capacities of their associates within the group, would add up to sufficient monetary strength to cover airline risk. Companies signed on to insure aircraft hull exposures, aircraft and airport liability exposures, and workers compensation.

The two MGAs were Associated Aviation Underwriters (AAU) in New Jersey and U. S. Aviation Underwriters (USAU) in New York City. I worked through most of the 1970s for USAU.

Aviation workers compensation is administratively intense, frequency of accidents is high. Most accidental injuries are minor requiring only medical services and involving no time lost from work. Some airline job descriptions include exposures not found in other industries or exist with higher probability among airline workers. Here are some cases:

  • Catastrophe potential, although very low, is real and unique to air operations.
  • Air turbulence is truly unique, can be very rough, and is often unanticipated by pilots. Flight attendants up and working are very exposed. When the pilot announces turbulence and turns on the seatbelt sign, too often flight attendants cannot get strapped in before being thrown to the ceiling or across rows of seats.
  • Strains and sprains inflight by pushing and pulling food and beverage service carts.
  • Lifting to assisting passengers with overhead luggage.
  • Galley hazards – hot coffee, burns.
  • Lift equipment, maintenance stands, their use and maintenance – very hazardous.
  • Aircraft maintenance hazards of fuel and fluid splash, fuel service accidents, high electrical exposure, fuel tank cleaning, aircraft flaps, brakes, tire changes, and other heavy systems repair exposures can be fatal.
  • Baggage handling strains may be usual but is much more strenuous in tight areas of aircraft cargo compartments.
  • Aircraft parking areas at busy terminals with continuous bustle of service vehicles.

MGA and Insurance Company Management and Services. – pre-deregulation.

Frequency and severity of airline losses are many and entirely predictable from year to year. Administration requirements are intense. Administrative services by professional insurance companies are necessary.

Underwriting: Loss costs being so predictable, standard rating procedures are not required. As such, being “self-rated” and virtually risk free, annual premiums are paid in installments on a cost-plus-expenses, reinsurance, boards and bureaus fees, taxes, and a small margin for manager’s profit. Risk of loss from catastrophe is reinsured separately with other specialty insurers.

Claims management: Compensability was determined by licensed and experienced claims managers employed by the member company insurers. Managers and adjusters of commercial insurance companies must and did comply with the established intent of the labor / management covenant – “in exchange for employer immunity from lawsuit, employee injuries incurred while performing the duties of the job will be accepted for compensation without regard to fault”.

Claims adjusters manage individual claims in compliance with state laws for the state in which a loss is filed.

Auditing: State bureaus provide periodic auditing of businesses to monitor statutory compliance, rates identification and procedures, payroll-based rate allocation, claims services, and much more.

Loss control services: USAU provided loss control services for several of our insured airlines. Services were provided by me and the special aviation loss control department at The Hartford Insurance company.

This arrangement performed smoothly and with rarely a complaint during the regulated decades.

Post-airline deregulation

(No dependable references exist. The following information is drawn from personal experience working beside airline management and insuring workers compensation programs.)

In mid-1980 every major airline in the USA cancelled their commercial workers compensation insurance at about the same time. We surmise that flush with revenue from C.A.B. dictated ticket prices, they were able to service all operating expenses leaving excess balance to prove financial responsibility. They then adapted to a brand of self-management of their workers compensation risk that suited themselves and seen to be  suitable to the bureaus in various states of operation.

Underwriting: Since airlines were accustomed to paying all medical and indemnity costs plus expenses, underwriting, per se, remained unnecessary. They would pay claims as determined “in-house”.

Compensability: No information is available from any airline on just how this is accomplished and whether statutory requirements are considered. Interviews and testimony from injured flight attendants suggests little or no compliance.

Elaborating: We know that in1985 when the Civil Aeronautics Board closed for business, air carriers fell upon each other to grab city pairs, routes, airports, gates, and schedules sufficient to establish competitive advantage each against the others. Although anticipated, aggressive cost cutting ensued that saw many expenses of benefit to employees and passengers stripped from the balance sheet. Termination of regular maintenance of engines and APUs are thought to be the most damaging of avoided costs, perhaps with one exception – Workers Compensation.

Injured flight attendants, every one of several dozen I’ve spoken with, attest to total denial of their injury claims or at best, some coverage that lasted until their files were closed, often prematurely. Since the buck stops in the chief executive’s office suite, we assign compensability decisions to the office. Not only are statutorily compensable claims being denied, the covenant of no fault acceptance of employee claims has been abandoned. The employer’s freedom from lawsuits, however, remains in place.

Conflict of Interest: From this evidence we conclude that when a corporate executive is responsible for the corporate bottom line; while always under pressure to appease shareholders, he becomes torn with conflict when faced with large obligations to pay for employee health issues. When bona fide claimants are denied statutory compensation, the executive is transferring the cost of its corporate obligation onto the personal accounts of employees. I have presented this case to the Chief Fraud Investigator of a state workers compensation bureau. He understands.

Claims management: Managing workers compensation and the more demanding claims administration burden is beyond an airline’s corporate business description. Perhaps airline staff were incapable of accomplishing this tedious work professionally. Airlines soon contracted with claims management specialty companies. These companies are not affiliated with the insurance industry. Several such companies have come and gone over the last 40 years. Some appear to be out of business. Most have departed airlines for reason unknown.

Sedgwick: Sedgwick Claims Management Services appears now to be managing claims for all or nearly all of the seven major carriers in the USA. Sedgwick manages claims by telephone and by email as follows:

Dealing with Sedgwick claims adjusters is a frightful experience for airline flight attendants. When a “first report of injury” is filed, the automatic response is to deny (At least this is so at American Airlines, although other airlines experience a similar initial responses). Thereafter, the injured employee must make her or his case directly by telephone or electronically. This often leads to:

  • he-said-she-said telephone tag that makes the process extremely frustrating.
  • allegations suggesting the claimant did not respond to requests for information even though the documents were sent.
  • Recorded telephone requests by Sedgwick for documents are alleged but no such calls were received or recorded.
  • Unending requirements for independent medical examiner (IME) review usually in a city far removed from the injured employee’s residence.
  1. a)   One such case on file involves a permanently fumes-disabled flight attendant to fly from Florida to Boston for the IME. During the return trip, the aircraft had a fume event (carbon monoxide) causing crew fatigue and the flight attendant and her husband to go to sleep. When they awakened, both were groggy and ill. They managed to drive home where the flight attendant could access her personal oxygen system. Her husband needed a week or more to feel well again.
  2. b) Similarly, a flight attendant friend who is partially crippled was made to travel to another city to a specific doctor. The doctor turned out not to specialize in the injury that he was supposed to evaluate. (Auditors of workers compensation programs might be watchful for questionable alliances between claims adjusters and favorite medical examiners.)
    Sedgwick assigned a “special investigator” to shadow her for days. He almost ran her off the road while driving.  She finally reported him to the police who then intervened.

This treatment is always applied to fume injury claims where virtually all are permanently denied.  It seems also to apply to physical trauma where medical and lost time from work will be expensive.

  • A flight attendant with a serious back injury incurred while working was made to wait more than a year for the necessary operation.
  • A flight attendant from another airline suffered a seriously torn rotator cuff as she tried to get seated and into her seatbelt and shoulder harness before expected turbulence occurred. The harness wasn’t quite secured when the aircraft lurched. Her injury would require surgery.
    The airline had installed a rule stating, “When the captain turns on the seat belt sign and announces passengers should remain in their seats, flight attendants not seated with seat belt and shoulder harness securely fastened who become injured will be denied workers compensation benefits.” The injured employee filed for compensation, was honest in reporting how her injury occurred, and was denied workers compensation. Cost to her family for medical services was approximately $60,000, as confirmed to me by her husband.

(In the 1970s we accepted many similar injuries and the airlines were able to cover them. Is this cost now so high that a corporation is not expected to comply with rules of workers compensation?

For a flight attendant who is up an working and may be the length of the cabin away from her assigned jump seat, such a rule is unfair and operates in defiance of the no fault covenant that is the underpinning foundation of workers compensation.

  • Still another: on a trans-Atlantic flight where fumes were apparent before or shortly after takeoff, flight attendants displayed illness symptoms. One soon became unusually incapacitated. Seeking rest in a below deck compartment, she continued to worsen. The captain on this flight was dismissive of flight attendant concerns and continued the flight. During the crossing, reports from her friends confirm unconsciousness on four occasions. Onboard physicians and other medical specialists revived her each time but could not diagnose her illness, which was simply, carbon monoxide poisoning from the combination of hot engine oil meeting with warm sealing air in the engine compressor bearing sump. The resulting CO leaks from the sump and into the Environmental Control System that serves breathing air into occupied areas of the aircraft. The captain now burdened by ill passengers and cabin crew landed at a remote airport in Canada from where the victims needed to be bused to a larger town for medical help.

The flight then continued to destination where most occupants were by this time also ill.

The seriously ill flight attendant was denied workers compensation, became destitute., and has been rescued by her family. Suffering from multiple chemical sensitivity (MCS), she lives the life of a semi-recluse trying to recover alone from her experience.

Last and perhaps most important, some airlines have not only denied indemnity for all cabin fumes-related injuries, they have also forced crewmembers to work in cabins with known fumes telling them the fumes are not dangerous. Management either doesn’t know or doesn’t tell employees these incidents are dangerous carbon monoxide fumes. They also charge punitive points against employment records if ill employees take time off to recover from fume injuries. Employers do not provide oxygen for detoxification of CO from their circulatory systems. Ill, injured, and disabled crewmembers, and possibly airline passengers, exist in society today as the icebergs exist in the sea.

The Federal Aviation Administration

When the C.A.B. closed for business on January 1, 1985, it emphasized that FAA responsibility for safety and health oversight of the airline industry would remain in force. Officially, FAA responsibility has remained. Actually, FAA oversight has been missing for the last 37 years. This may not be the fault of FAA officials. In 2012, a soon-to-retire FAA official was awaiting the new fiscal year allocation from the Congressional Budget Office (CBO). Our telephone conversation confirmed that inadequate congressional funding had hamstrung for decades the ability of the FAA to meet its responsibilities. This person was beginning to consider which services could be continued and which would have to be curtailed.

It is commonly known that airlines contract with foreign maintenance and overhaul facilities where labor costs are low. The FAA is mandated to assure all such facility operate in compliance with related repair and service regulations, FARs. Funds are not available.

Reports of aircraft fume events and the illnesses, injuries, and disabilities that result are categorized by the FAA as defined in FARs – “incidents”. As such, investigation of fume events need not be investigated. Incidents are accidents waiting to happen. I have never seen or heard of a fume event being investigated. I have personally investigated more fume events, however remotely, than the FAA. Since prevention is, or should be a primary responsibility of the FAA, Congress is derelict for not allocating funds. Case in point:

The U.S. Airways crew of flight 1041 made its January 16, 2010 approach to Charlotte, N.C. with two fumes-incapacitated pilots at the controls. The crew has long been keen to assure their story is told, the nearly catastrophic situation investigated. Seeing no concern from the FAA, in 2017 they consolidated their considerable medical and experience records confirming the flight, their trauma, and disabilities caused by diagnosed carbon monoxide poisoning. Granted an appointment with FAA officials, they went to Washington, D.C. taking the boxed-up records along. their purpose was to ask the FAA to redesignate the “incident” as an “Accident” under the FARs so that they FAA could investigate their case. The meeting went fairly well. The authorities agreed to review the document and respond with their decision. At least three months went by with no response.

Finally, their box of records was returned without comment – unopened

Goals and Objectives

This project petitions Congress and the airline industry to change, primarily for CO detoxification purposes using 100% oxygen.

First and Foremost

Oxygen will start the process ridding hemoglobin and myoglobin of carbon monoxide.
Affected employees and passengers will be spared most if not all short and long term illnesses that follow untreated carbon monoxide poisoning.

In addition, and by association, we affirm and ask that:

  • Government oversight is guaranteed in support of sound business practices. Oversight must be brought back to the industry with sensitivity for those conditions that affect human health and flying safety.
  • FAA work diligently to find cost-effect solutions to the contaminated cabin air issue.
  • Workers compensation auditors survey airlines for standard issues and by questioning employee groups of aircrew members, labor union members, and others to arrive at a reasonable assessment of accident causes, frequency, and severity of accidents.
  • Re-affirm airline financial responsibility to be allowed to continue to be self-insured. If any one airline fails financial responsibility tests, all airlines must return to commercial workers compensation programs. Allowing some to proceed with self-insurance while others return to statutorily sound programs will be competitively unfair.
  • Investigate Sedgwick Claims Management Services. Emphasize injured worker interests over and above that of the employer. Come together with other states to form a unified front against substandard workers compensation claims services.


Sedgwick is blatant in its defiance of state laws. Sedgwick Claims Management Services is the industry’s fraud enabler.

Please refer to Sedgwick Complaints Board websites. This evidence is not airline specific but the complaints mirror the tales herein.


Perhaps the best documented of much recorded evidence of ‘Aerotoxic Poisoning’ on a single, one way ‘non fume event’ flight to a large (40) group of unknown passengers (including young children) with elements of possible CO exposure ever recorded over six years:

Flight XLA 120 1st February 2007 – 20 plus group of UK passengers ‘seriously injured’.

  1. HOUSE OF LORDS Science and Technology Committee 1st Report of Session 2007–08 Air Travel and Health: an Update. Page 53.
  1. Mrs Samantha Sabatino and her family flew from London to Florida in February 2007. During the flight some 40 passengers became ill, including herself and three members of her family. Upon arrival to Florida she was hospitalised suffering from wheezing and crackles in her chest. No infection or viruses were found either in Florida or upon her return home. Her family were still experiencing ill health including violent nausea, tummy cramps, blisters on arms and hands, chest pain, severe headaches, vertigo, insomnia and loss of balance. She had complained to the carrier, XL Airways, who had denied that other passengers had complained of ill health. The Environmental Health Department have not carried out an investigation into the issue. She received unsatisfactory replies from the Health Protection Agency, the CAA and the Air Transport Users Council. She complained of being swept aside and questioned the effectiveness of these organisations.
  1. Documentary film 2007: ‘Welcome aboard toxic airlines’.
  1. 21 April 2008 BBC Panorama ‘Something in the air’:
  1. 3 May 2010:

Stewarts Law +44 (0) 207 822 8000 (London)
+44 (0) 113 222 0022 (Leeds)

Boeing 767 Flight Number XLA 120 Aerotoxic Poisoning

03 May 2010

The Stewarts Law Attorney Group represents 20 British passengers who were seriously injured by aircraft toxic fumes exposure on 1 February 2007. The incident occurred when they were flying on board an XL Airways Boeing 767 from London Gatwick to Sanford International, Florida.

The dangerous toxins were released into the cabin through the bleed air system which (as on most airliners) draws high pressure air from the core of the engines to pressurise the aircraft with breathable air. It has long been known that this design can result in the cabin air becoming contaminated with toxic oil vapour when the engine oil seals leak.

The toxins were detected by passengers as they began to notice and odd smell similar to ‘smelly socks’. The cabin seemed more ‘stuffy’ and ‘hot’ than any previous flight they had been on and the air severely their eyes, nose and throat. The passengers quickly became ill, suffering respiratory symptoms, severe headaches, vomiting, bowel problems, skin blistering and extreme fatigue. The toxic air also caused long term chronic effects such as respiratory problems, memory loss, sleep disturbances, chronic fatigue, mood swings, cognitive difficulties, infections, and joint/limb pains.

In order to put pressure on the US manufacturers to deal with these known cabin air problems and to obtain fair compensation for the passengers, on 29 January 2009 specialist litigation firm Stewart’s Law filed the case in Illinois, the state where the Boeing has its Headquarters. In addition to Boeing, the case was filed against Hamilton Sundstrand (which manufacturers air systems components), United Technologies (which manufacturers the Pratt & Whitney engines) and the owners of the aircraft – AAR Parts Trading Inc.

This is an out right US product liability case against US defendants. However, the defendants were intent on having the case sent back to the UK courts (which are much more expensive for claimants and award much lower compensation) so they filed a forum non conveniens motion arguing that the UK is the most convenient place for the litigation.

After the prolonged legal battle, on 3 May 2010 Judge Quinn decided in favour of the passengers and dismissed the defendants’ forum non conveniens motion. Stewart’s Law has achieved a great victory for the passengers. Securing US jurisdiction along with the prospect of a high profile jury trial is a wake up call for US manufacturers – unless they take measures to improve the quality of cabin air now, they will face the credible prospect of expensive and public US litigation for future incidents where there is an identifiable toxic fumes leak that causes injury.

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  1. 3 December 2013 60 minutes ABC Australia TV documentary. ‘Toxic Flyer’. https://www.youtube.com/watch?v=bM5Ht5v6c8g

How did the legal case for 20 UK passengers who were seriously injured conclude?



Foundation material for this document and all documents in this project are based upon statements made to us personally by ill, injured, or disabled aircrew members and passengers. Supporting material is provided by lists of fume events at airlines where such information could be requested of crewmembers. Local media reports of fume events are included.

This much supporting documentation is too bulky to be provided initially. Accommodation will be made upon request.

Posted 14th July 2022

John M. Lind CPCU ARM

crewadvoc8@yahoo.com or



John G. Hoyte

Chairman Aerotoxic Association Ltd. The Charity – 2007
Aerotoxic Solutions Consultancy Ltd. – 2021

Former BAe 146 Training Captain



FUCKING CAA!!! Lying bastards & All lawyers….

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