Contaminated Aircraft Air and Crews

Source: Aviation Contaminated Air Reference Manual

When Change Was Needed It Did Not Occur © 10th April 2008
by Susan Michaelis

There are three main reasons why the FODCOMs, SBs, ADs and AOMs failed to rectify the problem.

Firstly, the BAe 146 checklist was changed to add the word ‘Fumes’ although the initial BAe 146 2001 AOM Ref 01/004V actually stated the requirement for the pilots to use oxygen, ‘any time that unusual smells indicating the presence of fumes are detected, as there is a possibility that these may be associated with incidents of suspected crew incapacitation.’ The checklist change was not adequate. The checklist should have been changed to add the phrase, ‘Suspected Contaminated Air or Fumes.’ Many crews will have interpreted the information as requiring them to positively identify that the air was contaminated, rather than merely suspect this to be the case. Additionally, they could assume they were only being advised to use oxygen under positive identification associated with incapacitation only. This on the face of it could advise the pilot that adverse effects and impairments are to be disregarded. Some crews will view fumes to mean a non visible smell, while others may still view that a fume has a visible component to it as well, as seen below in the dictionary definitions of ‘fume.’

Compact Oxford Dictionary On-Line [69]:

Noun: fume: A gas or vapour that smells strongly or is dangerous to inhale.

WordWeb On-Line [70]

Noun: fumes

Gases ejected from an engine as waste products - exhaust, exhaust fumes

Noun: fume: A cloud of fine particles suspended in a gas - smoke

Verb: fume: Emit a cloud of fine particles - ‘The chimney was fuming’ - Smoke

The word ‘fume’ will mean different things to different people, some will understand fumes to mean smells but others will expect a visible element like misting rather than smoke. The unusual smells part was key for change to occur and was not given the emphasis it should have. Additionally, the term ‘suspected unusual smells / fumes’ or ‘contaminated air’ should have been included. In fact, some current checklists for other aircraft types now are headed as, ‘Air conditioning, smoke fumes and suspected contaminated air.’ [71] The Airbus A320 checklist refers to the, ‘smoke / toxic fumes removal’ requiring actions to be taken for, ‘dense smoke or toxic fumes.’ [72] An interesting point is that the aviation industry to this day advises that the fumes are not toxic and therefore crews usually disregard advice given by the regulators and manufacturers. Why act when in Airbus terms you only need to act when ‘toxic’ fumes are present when you are told contaminated air is not harmful?

Secondly, most crews never saw either of these AOM messages despite the messages saying they should be informed on the front page of the notice. [73] Even cabin crew were meant to see AOM 00/030V but we have never met any who did. Most BAe 146 pilots will tell you the contaminated air smell was so extremely frequent and familiar to them that for any change in habit to occur they needed stronger guidance than an AOM few ever saw. [74] The ambiguity contained within the AOMs and the fact that the regulator and most airlines did not take any responsibility and push these important points resulted in little change in the way crews dealt and continue to deal with contaminated air. Crews on the whole simply continued the way things were.

Thirdly, and most importantly, there was no active education of crews. The BAe 146 as a BAe 146-100 made its first flight on 3rd September 1981 and yet these British Aerospace, All Operator Messages offering guidance on contaminated air were coming out nearly twenty years later. Twenty years of crews regularly being exposed to contaminated air on that aircraft type whilst simultaneously being told there was nothing to worry about means one thing for certain. It means that a massive educational program is needed to change the status quo. Apart from not seeing the AOMs, most crews would never have seen a SB or AD and few would read the CAA FODCOMS. Crews rely on their employers, the airlines, to tell them what to do or for the CAA to contact them if something was very urgent. Neither the AOMs, SBs, ADs or FODCOMs or the information contained within these documents was sent to all pilots, by any national regulator. Yet the national regulators such as CASA, the UK CAA or the FAA all have the mailing address of all professional pilots on their database. The national regulators also know exactly who holds a licence to fly each particular aircraft type, known as an aircraft ‘Type Rating.’ If they really wanted to overcome the complacency that existed and seriously educate crews, they could have written to all pilots or to all pilots who were specifically qualified to fly the BAe 146; however this did not occur.

The regulators turned a blind eye on airlines who did little to get the message across. When visible smoke is present in the flight deck we would say most crews would use oxygen as this has to be the sensible option. Everyone knows fire fighters go into burning buildings with breathing apparatus so it’s not a difficult step for crews to take and most would - they are professionals. All airlines would also want crews to use oxygen in serious smoke situations; however, by educating and telling crews to take contaminated air events more seriously they would have immediately increased their operating costs when contaminated air events occurred through increased maintenance costs and aircraft down time. Therefore, the airlines response was on the whole grossly inadequate with most airlines simply changing the checklist to comply with the regulations but not carrying out the much needed education process. The consequence of this lack of vital education is that the status quo pretty much continued. Crews continued not to take contaminated air seriously and also failed to report contaminated air events as they should. These last points cannot be overly emphasised.

Evidence of the operators resistance to the requirement to report all fume events on the BAe 146 as required by the 2001 AD was aired at the 2001 BAe 146 Operators Conference. The minutes report: [75]

  • John Lahart (Aer Lingus) is concerned that they’ll end up grounding the fleet due to crew upon the AD being released.

  • Roger Lien (Mesaba) expressed concern the crews will be writing up everything unnecessarily.

  • Comment from audience: Condition to inspect engines will ground aircraft. MEL is allowed, but pilot may refuse the continued use of aircraft. Inspectors may ground aircraft.


Flight Safety Aspects of Contaminated Air


References

69. Available at: http://www.askoxford.com/concise_oed/fume?view=uk.

70. Available at: http://www.wordwebonline.com/en/FUMES.

71. Major UK airline B737 non normal checklist. November 2005.

72. Airbus A320 abnormal and emergency procedures: Smoke toxic fumes removal. 3.02.26. rev 23.

73. UK BAe 146 crew advice to AOPIS. 2005.

74. UK BAe 146 health and exposure survey of BAe 146 pilots: 86% of pilots had experienced contaminated air smells on the BAe 146.

75. ALF 502R/507 Operators Conference. February 22, 2001. London. BAe 146.


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