Contaminated Aircraft Air and Aviation Industry

Source: Aviation Contaminated Air Reference Manual

Aviation Industry Could Have Acted © 10th April 2008
by Susan Michaelis

When the first reports of contaminated air were presented to the airline industry it could have acted as it has in other areas of aviation where serious flight safety issues have become apparent. In some cases the aviation industry has acted with great success and should be applauded for doing so. Mid air collisions have occurred repeatedly since commercial aviation came about. These were invariably due to Air Traffic Control (ATC) or pilot error but when they occurred fatalities where usually high. In the 1970s there were several big events such as on 5 March 1973 when an Iberia Douglas DC9-32 had a midair collision with a Spantax Convair 990 near Nantes, in France. All seven crew members and 61 passengers were killed on the DC9 died but miraculously the Convair 990 landed safely. On 10 September 1976 an Index Adria Douglas DC9- 32 had a mid air collision with a British European Airlines Trident 3B near Zagreb in Yugoslavia resulting in 176 deaths. On 25 September 1978 a Pacific Southwest Boeing 727-200 had a mid air collision with a single engine Cessna near San Diego in California, the crash resulted in another 150 deaths. [48] What these three events and others like them previously did was to force the aviation industry to act and act they did.

The US FAA had been looking into these issues for many years and in 1981 decided to deal with them by developing an in-flight anti collision system. [49] The solution which came out of the need for an improvement to flight safety is now fitted to every large commercial jet aircraft in the world and is known as TCAS or the Traffic Alert and Collision Avoidance System. TCAS is a clever electronic system that scans the vicinity of an aircraft by interrogating the transponders of other aircraft. It then uses the received transponder signals to compute distance, bearing and altitude relative to the aircraft. The evaluated traffic information is displayed as symbols on the pilots flight instruments usually the navigation display. When TCAS detects that an aircraft’s distance and closure rate is becoming critical, TCAS generates aural and visual annunciations for the pilots to enable them to manoeuvre their aircraft safely out of each others way. If two aircraft were at the same height heading straight for each other, one pilot would be told to climb and the other descend. TCAS has saved thousands of lives since its introduction.

Many say the difference between dealing with mid air collisions and contaminated air exposures is the obvious. Mid air collisions claim lives immediately which the media are quick to highlight. If contaminated air exposures result or play a role in a hull loss it will be put down to pilot error anyway. The reason for this is that without evidence from contaminated air detection systems or appropriate blood tests (neither of which exist), fumes will not be investigated as a major factor. Another reason for the industry not tackling the problem as they should is that the link between the contaminated air events and immediate health effects are frequently misdiagnosed. Passengers rarely make a link between ill effects and contaminated air as the industry fails to highlight these risks. The consequences are that there is clearly little incentive to get to know the scale of the problem or to rectify it. Others claim that the industry is reluctant to address a problem which has already left its impact on those previously exposed.

If a passenger or crew member gets sick it’s very easy to blame it on something else. But what the airline industry certainly cannot say, is it never knew the risks of exposure to contaminated air containing pyrolised synthetic jet engine oils. In 1977 a 34 year-old navigator on a US Air National Guard Lockheed Hercules transport aircraft was incapacitated and a paper was then written by the head medical doctor for the Air National Guard, Dr Wier and colleagues. Dr Weir had treated the navigator and clearly realised that this person had been exposed and suffered effects from exposure to contaminated air on the aircraft and that such fumes characteristic with synthetic jet engine oils, were not infrequent. Dr Weir and his team in this 1977 paper stated: [22]

  • Disturbance in the mental and neuromuscular function of aircraft flight personnel by any influence is of obvious concern and significance. This report documents the incapacitation of an aircraft navigator during flight. This situation resulted from an inhalation exposure to aerosolized or vaporized synthetic lubricating oil.

    • And most importantly that:

  • Further investigation into the potential hazards from inhalation of synthetic oil fumes that are generated by these circumstances is definitely warranted.

    • This call for proper investigations into the potential hazards of inhaling synthetic oil fumes was never met for the synthetic engine oils used in commercial aviation. All these years later we do not know how these toxicity mechanisms work, we just know the effects. However, the airline industry is relying upon this by ignoring the effects as the toxicity mechanisms are not fully understood, instead of recognizing that a serious health and flight safety issue is occurring and then working out the mechanisms to rectify the problem. As will be seen later on, the research that has been undertaken by most Governments and industry to date to determine what is going wrong has been woefully inadequate and in many cases very misleading.

    While most within the airline industry were quick to state that these incidents were outside the expertise and responsibility of the aviation industry, their actions, as will be seen shortly, clearly showed these events clearly were major safety concerns. CASA clearly stated that contaminated air events were not its responsibility and did not see them as a serious safety issue and if it did it would have to take serious actions such as grounding aircraft. [50][51] While airlines such as National Jet Systems in Australia advise that their aircraft meet all the aviation regulations, [12] they do so knowing the regulators and the manufacturers are saying the same. British Aerospace advised the Australian Senate Inquiry in 1999 that its aircraft was certified in 37 countries with 350 aircraft operating with 52 airlines. It advised that in 1998 in light of the cabin odour reports, CASA and the UK reviewed the air conditioning standards and its compliance with certification and that it understood CASA was satisfied with the review. [52] Qantas advised likewise that, ‘the aircraft meet Australian certification requirements for cabin air’. [53] CASA actually went a step further and advised that it had reviewed, ‘the certification of the BAe 146 aircraft and is satisfied that the aircraft meets the standards applicable at the time of introduction of the aircraft into Australian service.’ [54] CASA went on to advise that it actually went back to ensure the documents had actually been produced at the time of the aircraft certification. [14] However, Richard Best, a former CASA airworthiness officer advised that when he issued the first ever type rating for the BAe 146-300 aircraft in Australia, they only reviewed CO, CO2 and ozone. [55]

    The UK Government made the point very clear that it reviews cabin air standards only at the time of initial certification of the aircraft by way of answers in the House of Lords including the statement: [56][57]

  • Commercial aircraft ventilation systems are designed to supply air of an acceptable standard. This is confirmed at initial certification and, thereafter, each aircraft is subject to scheduled maintenance actions to ensure those standards are maintained. Where problems are encountered in service these are investigated and changes or repairs are introduced as necessary.

    • By reviewing the contaminated air events that are occurring globally, the examples listed above and in the appendices, the frequency of events chapter and sample investigation reports, in no way could it be said that the system is working and that there is not a major flight safety issue. It is clear, based upon the type of events, the frequency of events and the recurring nature of events, that checking the air conditioning and air quality systems at aircraft certification, which might be as far back as the early 1980s, is not addressing the problem. To suggest that scheduled maintenance will detect such problems is clearly not happening either. For example, major checks of the air conditioning system may only occur at every ‘C check’ which will take place between every 12-18 months or more and may take between 10,000 - 30,000 man hours. [58] It is clear from the ongoing contaminated air events that maintenance is not adequately addressing such events in service. There is a blind refusal to recognize the severity of the effects of contaminated air. The aviation industry way of dealing with these events is to severely downplay or ignore many contaminated air events.


    Flight Safety Aspects of Contaminated Air


    References

    12. National Jet Systems (2000) Hansard Evidence by National Jet Systems to the Australian Senate inquiry into air safety (1999–2000) BAe 146 cabin air quality. Parliament of Australia, Canberra.

    14. Civil Aviation Safety Authority (1999-2000) Hansard Evidence by CASA to the Australian Senate inquiry into air safety (1999–2000) BAe 146 cabin air quality. Parliament of Australia, Canberra.

    22. Montgomery MR, Wier GT, Zieve FJ, Anders MW (1977) Human intoxication following inhalation exposure to synthetic jet lubricating oil. Clinical Toxicology 11:423–426.

    48. Available at: http://www.airsafe.com/events/midair.htm.

    49. Available at: http://www.aviationtoday.com/cgi/av/show_mag.cgi?pub=av&mon=0402&file=0402prodfocus.htm

    50. Australian Broadcasting Commission (ABC) Radio, News in science, 11 December, 2000: Possible solution to toxic aircraft cabin air- CASA. ‘We don't regard fumes as an immediate threat to aviation safety… …Obviously if we did we would have to ground flights.’

    51. Civil Aviation Safety Authority (1999) Toller, M. Hansard Evidence by CASA to the Australian Senate inquiry into air safety (1999–2000) BAe 146 cabin air quality. Parliament of Australia, Canberra. ‘When you start talking about the general subject of toxins in atmospheres, and specifically in this case in the atmosphere within an aircraft, then it is outside CASA’s area of expertise. We are responsible for aviation safety. I think we are now getting into occupational health and safety issues which I think you need an expert in occupational health and safety to consider rather than an aviation safety authority.’

    52. British Aerospace (1999) submission by British Aerospace to the Australian Senate inquiry into air safety (1999- 2000) BAe 146 cabin air quality. Parliament of Australia, Canberra.

    53. Qantas (1999) submission by Qantas Airways to the Australian Senate inquiry into air safety (1999-2000) BAe 146 cabin air quality. Parliament of Australia, Canberra.

    54. CASA (1999) Submission by CASA to the Australian Senate inquiry into air safety (1999-2000) BAe 146 cabin air quality. Parliament of Australia, Canberra.

    55. Best R (2001) Certification of aircraft in Australia. Aviation air quality. In: Winder C, Michaelis S, Weber RO (eds) Proceedings of the Aviation Air Quality Symposium, Australian Defence Force Academy/University of New South Wales, 7 December 2000, University of New South Wales, Sydney, pp 78–82.

    56. UK House of Lords written question. Lord Tyler [HL 1938] 7 November, 2005.

    57. UK House of Lords written question. Lord Tyler [HL 2312] 1 December, 2005.

    58. Available at: http://www.aa.com/content/amrcorp/corporateInformation/facts/fleet.jhtml.


    The Airline Pilots Forum and Resource