Contaminated Aircraft Air
Aviation Safety and AirworthinessSource: Aviation Contaminated Air Reference Manual
Aviation Regulators Misinterpret Main Ventilation
Airworthiness / Safety Standard ©10th April 2008 by Susan Michaelis The denial that many contaminated air events are safety related can in many ways be traced back to the CAA’s incorrect interpretation of the main global aviation airworthiness ventilation regulations. These will be dealt with in greater detail in the Chapter 15. However, the main issues in relation to flight safety and contaminated air are partly contained within the primary regulation stating whether an aircraft is deemed airworthy or fit for flight. This is FAR / JAR / EASA 25.831. Part 25 Airworthiness Standards: Transport Category Airplanes. FAR 25.831- Ventilation, has been in existence since the early 1960s and requires that for an aircraft to be airworthy or safe for flight, that:
‘Each crew compartment must have enough fresh air… to enable crewmembers to perform their duties without undue discomfort or fatigue.’
‘Crew and passenger compartment air must be free from harmful or hazardous concentrations of gases or vapors.’ [98]
This major regulation clearly states that the air must not cause undue discomfort or fatigue and the air must be free of hazardous or harmful concentrations of gases or vapours in order for an aircraft to be airworthy and to therefore operate, especially with passengers onboard. However, by reviewing the contaminated air events collated from around the globe, as well as those listed in the UK contaminated air events database, this is clearly not occurring. Yet the aviation regulators refuse to acknowledge this.
In 2003, the CAA admitted that, ‘circumstantial evidence suggested potential contamination of cabin air by abnormal concentrations of noxious gases or vapours,’ but the safety risk was controlled by actions to date. [99] There are many other acknowledgements that the fumes are clearly related to oil lubricants and their pyrolysis products, as will be shown elsewhere. One such admission includes:
‘The ducts were contaminated with a carbonaceous material containing chemicals entirely consistent with the pyrolysis products of aircraft engine oil.’ [100]
However, failure to observe the main ventilation airworthiness requirements, 25.831 a/b continue.
What now follows is a review of the various reasons the Governments use supporting their denial, as well as the opposite view showing that contaminated air events are reportable and therefore safety related. What occurs in practice varies but in most cases supports the denial case and can clearly be seen in the contaminated air events appendices and frequency of events chapter.
Denial of Responsibility: Many Fume Events Are Not Safety Related and Not The Responsibility of The Aviation RegulatorAustralia: CASA
CASA completely ignores, ‘part ‘a’’ of the airworthiness / safety regulations requiring crews to operate without discomfort. This is apparent from the CASA statement on 25.831 of:
‘Aircraft design standards FAR and JAR 25-Ventilation - ‘Crew and passenger compartment air must be free from harmful or hazardous concentrations of gases and vapours. That is the only statement that is in there at present’.’ [14]
Somehow CASA only mentioned part ‘b’ of the regulation and conveniently forgot to mention part ‘a’.
CASA have also stated that:
‘Toxins in the cabin are an OH and S issue and not the responsibility of the aviation safety regulator.’ [14][51]
‘Fumes are not an immediate threat to aviation safety.’ [50]
‘Many contaminated air events are more of a health problem than an aircraft technical defect.’ [13]
CASA also misinformed the Government when they incorrectly stated that, ‘Prior to the issue of the AD by CASA, there was no specific requirement for National Jet Systems (NJS) to report to CASA on incidents of air contamination.’ [15]
UK: CAA / DfT
The Department of Transport (DfT) stated:
‘Air contamination would be considered to make an aircraft unairworthy if it was likely to incapacitate the aircraft's flight crew.’ [101]
‘The airworthiness design requirements… are limited in their scope in addressing health effects, and are almost exclusively confined to assuring environmental conditions that would not incapacitate the persons on board due to short term health effects and preclude continued safe flight and landing.’ [19]
To state that only incapacitation would make an aircraft unairworthy is complete misinformation as it fails to highlight that any contamination which caused any impairment would equally make an aircraft unairworthy. The DfT statement doesn’t even mention what the potential effects would be of exposing passengers to contaminated air.
In 2005, in the House of Lords, based upon previous answers given, the UK Government was questioned on its narrow view of whether an aircraft would only be deemed unairworthy in relation to contaminated air if incapacitation occurred. It was specifically asked if ‘undue discomfort and fatigue’ and ‘air fee of harmful or hazardous concentrations of gasses and vapours’ (FAR/JAR 25.831a/b) had to in fact be met for the aircraft to be airworthy / safe and the answer was the latter. By way of a one word statement, ‘YES’, the Government accepted that undue discomfort and fatigue and air free of harmful concentrations of gasses or vapours was indeed the criteria for aircraft safety or airworthiness. [102] This directly contradicts the CAA line that it is only incapacitation that is related to the airworthiness or safety of the aircraft and its occupants. It clearly demonstrates that the CAA and the Government have been using their own interpretation of what is a matter of airworthiness or safety in relation to contaminated air events while ignoring the actual aviation regulations or legislation.
Acceptance of Responsibility: Fume Events Are Safety Related and The Responsibility of The Aviation RegulatorAustralia: CASA
Fumes that adversely affect the air quality are considered a ‘major defect’ by CASA as confirmed by their statement:
‘All instances of smoke or fumes in the aircraft cabin that adversely affect the quality of cabin air on Australian registered aircraft operating domestically or internationally, are categorized by the Civil Aviation Safety Authority as a ‘Major Defect’.’ [16]
Interestingly, under the Australian aviation regulations, a ‘major defect’, ‘in relation to an aircraft, means a defect of such a kind that it may affect the safety of the aircraft or cause the aircraft to become a danger to person or property.’ [103]
This puts to rest the argument whether fume events are safety related or not or could be considered ‘lesser events’ as advised by the CAA and the UK Government.
UK CAA
Events affecting airworthiness of the aircraft must be reported to the CAA and are therefore safety related: e.g. contaminated air events that fall under FAR / JAR / EASA 25.831 ‘a’ and or ‘b’ showing undue discomfort or fatigue or harmful or hazardous concentrations of gases or vapours. To determine this it is necessary to look at the individual fume event report, the ongoing nature of similar reports as well as monitoring of the air and so on. While the CAA makes the following statements, it is clear they are not following it in practice as the ongoing nature of the reports as shown in Appendix 2, 6 and 7 and other reporting formats show undue discomfort is occurring, under and incomplete reporting is occurring and monitoring of the air during events is not happening:
‘The Civil Aviation Authority's Mandatory Occurrence Reporting scheme requires reports of contaminated air events where they are considered by the reporter to represent potential airworthiness concerns.’ [104][105]
‘The mechanism for the reporting of contaminated air events is well established through the Civil Aviation Authority's Mandatory Occurrence Reporting Scheme, the purpose of which is to receive reports of incidents affecting airworthiness.’ [82]
When questioned on whether FAR/JAR 25.831 ‘a’ and ‘b’ must be met for an aircraft to be airworthy and therefore, safety matters, the Government replied, ‘Yes.’ [102]
Any form of crew impairment that effects the efficiency of the crew to undertake their duties as required must be reported to the CAA and is therefore safety related: While this is what the regulations actually state as will be seen in Chapter 15 this is a direct contradiction to the incorrect CAA interpretation set out above that it is incapacitation only that is a safety issue or that the CAA is responsible for,
‘The Air Navigation (General) Regulations 1993 prescribe the mandatory reporting to the Civil Aviation Authority of any hazardous, or potentially hazardous, defects encountered during aircraft operations or maintenance. Specifically article 17(c) requires the reporting of any occurrence involving the impairment during a flight of the capacity of a member of the flight crew to properly undertake his or her functions.’ [97]
Contaminated air events are reportable occurrences to the CAA and are therefore safety related:
‘Incidents related to cabin air quality are among the list of examples of reportable occurrences.’ [106]
Worryingly the UK Committee on Toxicity Committee that is presently undertaking a review into this issue is oblivious to the fact that reporting of fume events is mandatory. While the CAA discreetly in some instances makes a comment that reporting is mandatory, by far the bulk of its information and communications do not support this. Therefore, the COT committee which has had numerous meetings and communications with the CAA is falsely under the belief that: ‘Fume reports are not required to be recorded in the aircraft tech log; Air safety reports and Mandatory Occurrence Reports are not required for all fume / contaminated air events and airlines are entitled to use discretion as to when fume events are reported to the regulator.’ [31] This position is not being corrected by the UK airlines or BALPA. While the IPA, TGWU, many crews, groups such as AOPIS and the newly formed GCAQE have clearly pointed out that the regulatory reporting requirements are not being enforced or followed, the COT committee, the CAA, BALPA (in late 2006 and 2007) and the UK airlines are allowing this misinformation to continue.
Flight Safety Aspects of Contaminated Air
Reporting Contaminated Air Events with Samples of Known Events
FODCOM (Flight Operations Department Communication) number 17/2000
FODCOM (Flight Operations Department Communication) number 14/2001 and 21/2002
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References
13. CASA , CCH Australia OH&S magazine, Feb-Mar, 2003, High on the flight deck, Helen Borger.
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.
15. Australian Parliament Hansard, Q 398, BAe 146 aircraft, 2 December, 2002.
16. Australian Parliament Hansard, Q3011: Air Safety - Cabin air quality, 29 March, 2004.
19. House of Lords, Select Committee on Science & Technology Report. Air Travel & Health, 1999-2000 – Memorandum by CAA SRG.
31. COT: Committee On Toxicity Of Chemicals In Food Consumer Products And The Environment (Cot). Update Discussion Paper (December 2006) On The Cabin Air Environment, Ill-Health In Aircraft Crews And The Possible Relationship To Smoke/Fume Events In Aircraft. Tox/2006/39.
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.’
82. Countess of Mar HL. Question in the UK House of Lords. Question number: 2311. 23 November 2005.
97. Countess of Mar. Question in the UK House of Lords. Question number: HL 1779 October 2005.
98. US FAR 25.831a – Airworthiness standard. Transport Aircraft - Ventilation. 1964.
99. CAA SRG 2003. Safety Initiative – Hazardous contamination of flight deck cabin air.
100. CAA cabin Air Quality paper, 2004.
101. UK House of Lords written question. Countess of Mar. [HL1763] 1November 2005.
102. UK House of Lords written question. Lord Tyler [HL 2911] 20 December 2005.
103. Australian Civil Aviation regulations 1988 (CAR) 2: definitions: Major defect.
104. UK House of Lords written question. Countess of Mar [HL 1637] 1 November 2005.
105. UK House of Lords written question. Lord Tyler [HL 1939] 7 November 2005.
106. UK House of Lords written question. Lord Tyler [HL 1940] 7 November 2005.
