The December 2000 Aviation Air Quality Symposium Statement

Consensus statement made by attendees at the December 2000 Aviation Air Quality Symposium at the Australian Defence Force Academy, UNSW, Canberra:

Symposium attendees:

1.                  Affirm and support the recommendations of the report of the Senate Inquiry into Oil Fumes on the BAe 146.

2.                  Urge the Commonwealth Government to implement all the recommendations in the report of the Senate Inquiry into Oil Fumes on the BAe 146 as fully and quickly as possible.

3.                  Deplore the absence of a representative of the Civil Aviation Safety Authority (CASA) from this symposium.  The reasons given by CASA for not attending, that is that the agency is too small to have technical specialists free and fumes are not viewed by CASA as immediate threat to safety are inadequate and unprofessional.

4.                  Consider that the mandatory reporting of odours and fumes as required under the current Civil Aviation legislation should be enforced more broadly than at present.  This reporting should be both internally to the respective airline, and externally to CASA and the Australian Transport Safety Bureau (ATSB) as required under existing legislation and to third parties (for example, by listing on a website).  This reporting should include recording of activities after the incident, such as relevant activity that identified and resolved the problem.

5.                  Consider that the presence of contaminated air in the cabin of airplanes in flight is a major defect as well as an airworthiness issue, as specified in the current regulatory framework.  Debate about this issue should not be centered on whether air is contaminated, but what to do when it is.  In agreement with a recommendation from the Senate Inquiry report, such airplanes should be grounded after such incidents until the defect that caused the problem is identified and fixed.  Information should be exchanged between the airlines, regulators and manufacturers so as to determine trends that may be occurring.

Regulatory considerations:

1.                  As noted by the Senate Inquiry in their report, the Civil Aviation Safety Authority should provide reasons why regulations relating to air quality on passenger airplanes appeared to be disregarded (or in any event, not enforced).

2.                  It is apparent that some officers of the Civil Aviation Safety Authority are of the opinion that occupational health and safety of employees in the aviation industry is not part of their responsibilities.  Because of confusion in (and outside) the aviation industry about who is responsible for occupational health of employees, the Civil Aviation Safety Authority should indicate those aspects of workplace safety that it considers are part of its responsibilities, with full references given to applicable Civil Aviation Regulations and legislation.

3.                  The terms “incident”, “major incident” and “safety deficiency” are defined in Section 19 of the Air Navigation Act.†  The Civil Aviation Safety Authority should provide written reasons why they do not consider that the presence of contaminated air in the passenger cabins of commercial aircraft sufficient to cause irritation and discomfort (as has been reported from a range of sources) is not considered an aviation incident under this legislation.

4.                  The Civil Aviation Safety Authority should provide a transparent definition of the term “contaminated air”.  If this definition includes such words as “hazardous” or “harmful” (or other similar terms), these terms should also be defined.  This definition should be published.

5.                  In the past, circumstances have arisen where the air of the passenger cabin of airplanes at ground and in flight has become contaminated sufficient to cause signs of irritation and discomfort in crew and passengers.  There should be enforcement of the already mandatory reporting of circumstances such as odours and fume incidents so as to ensure the regulations are adhered to.  Such reporting should not be kept within the airplane operator, but should also be subject to external notification to the regulatory authorities CASA and the ATSB, and published (for example, on a website).

6.                  The Civil Aviation Safety Authority should develop criteria that allow the recognition of circumstances when cabin air is contaminated sufficient to be considered a major defect.

7.                  The term major defect is defined under Section 2 of the Civil Aviation Regulations as “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.”  Superseded legislation described a major defect as: “defects causing or likely to cause smoke or gas contamination of any part of the cabin, cockpit or baggage compartment.”  Current CASA published examples of major defects include “smoke, toxic or noxious fumes inside the aircraft.”  The terms “toxic” and “noxious” should be defined. 

8.                  The Civil Aviation Safety Authority should also develop improved criteria that allow the recognition of circumstances when cabin air is contaminated sufficient to be considered a major defect.  Further, CASA should provide guidance for the defect categorisation of those events where the presence of sufficient contaminated air that gives rise to irritation and discomfort in crew and passengers is reported.  At present, these seem to be considered as “normal operations” or acceptable.

9.                  It is recognised that regulatory agencies, such as the Civil Aviation Safety Authority and the (former) Bureau of Air Safety Investigations (BASI) have resource limitations that, if overstretched, require priority setting in responding to matters for attention.  However, such limitations should not prohibit such agencies from the discharge of their responsibilities.

Engineering considerations: 

1.                  Any actions that will lead to a decrease (preferably a dramatic decrease) in engine oil and hydraulic leaks in engines in flight in planes being flown by Australian airlines should be strongly encouraged.  Options for such actions include better engines (it is recognised that the cost of re-engining planes is probably prohibitive), better seals, use engine oils with less toxic ingredients. 

2.                  There is a lack of information about the various options that have been considered and either adopted or rejected, and this leads to distrust.  Of those that have been adopted, there is a lack of information about why they were chosen over others, and what criteria will be used to assess their effectiveness.  CASA should provide a list of the options that it regards as being suitable for consideration as addressing the problem of engine oil leaks.†

3.                  The possibility of installing suitable monitoring technology, such as a sensor at the level of the bleed air inlet that could detect and warn about contamination of oil and hydraulics in bleed air needs consideration.

4.                  It must be recognised that once oil has entered the bleed air system, full cleaning downstream of the source as soon as practicable is required in addition to rectification of the leak.

Operational considerations:

1.                  An engine that is identified as leaking should be isolated and not used for bleed air purposes for the remainder of that flight.  Full rectification of the causes of the leak in such a manner to prevent a leak from the same source from recurring must take place as soon as is practicable, and in any event, prior to further flight.

2.                  Airplanes with known problems of engine oil leaks into bleed air should only be flown with air circulation in the fresh air mode only (that is, no re-circulation) to the next suitable landing point.  

3.                  Aircrew (either pilots or flight attendants) showing or reporting signs of intoxication after engine oil exposure should be required to sit down and be given oxygen through a respirator.

4.                  Aircrew (either pilots or flight attendants) showing or reporting signs of intoxication after engine oil exposure should be required to undergo medical evaluation immediately after landing, and as long as symptoms last after an exposure event.  Such personnel should have blood samples taken for cholinesterase testing as part of this medical evaluation (guidelines on collection and storage of such samples should be developed by CASA).  Samples should be made part of a chain of custody system, and analysed by a reputable laboratory, such as the NSW WorkCover Authority.

Worker health:

1.                  Steps or a procedure should be developed that allow concerned employees to come forward to discuss issues with management without penalty to career, seniority or benefits.  Notwithstanding assertions made by the airlines to the contrary, such a procedure does not yet exist in any airline at present.

2.                  Airline operators should review the medical literature to identify a test suitable that allows identification of exposure to airborne contaminants during oil leak events.  This test should be specific to the exposure (for example, the newer cholinesterase testing for organophosphate testing developed by the NSW WorkCover Authority).  The results of this review should be made public.

3.                  The airlines should develop a database of symptoms that arise in aircrew, or are reported as being associated with airplane flight.  Subject to suitable confidentiality requirements, this database should be accessible to third parties bodies (for example, by inclusion on a website).

4.                  A study should be carried out investigating the role of long term tissue hypoxia in aircrew during flight using pulse oximeters.

The attention of the aviation community should be brought the inequalities inherent in the uneven burden of proof required to establish health and safety matters (such as whether oil leak emissions can affect health), as compared with the trifling level of proof required that allows an existing practice (for example, a absurdly high level of engine oil leaks) to continue.  The level of proof in both cases should be on the balance of probabilities, and not the level of proof required by scientific and statistical conventions.


†    S19AC Meaning of incident: An incident is an occurrence, other than an accident or a serious incident, associated with the operation of an aircraft that affects or could affect the safety of the operation of the aircraft Or another aircraft.

             S19AB Meaning of serious incident: A serious incident is an occurrence associated with the operation of an aircraft that affects or could affect the safety of the operation of the aircraft or that involves circumstances indicating that an accident nearly occurred.

             S19AD Meaning of safety deficiency: A safety deficiency is constituted by any situation related to aviation that can reasonably be regarded as having the potential to affect adversely the safety of aviation

†           In the past, CASA has been accused of taking industry information and presenting it uncritically as its own.  This is unacceptable.  The list of options should be developed within CASA, and not by reference to the airplane manufacturers and operators.