AIRCRAFT AIR SUPPLY CONTAMINATION

IFALPA- International Federation of Airline Pilots

Submitted by
Australian Federation of Air Pilots (AUS-ALPA)

Contact:
Lawrie Cox
Senior Industrial Officer
Australian Federation of Air Pilots
132-136 Albert Road
South Melbourne Victoria
Australia 3205

+61 (0)3 9699 4200 Phone
+61 (0)3 9699 8199 Facsimile

Email: lacox@bigpond.com

SUMMARY AND RECOMMENDATIONS

IFALPA POLICY RECOMMENDATIONS

The aviation industry recognises that the problem of air supply contamination occurs, through service bulletins, defect statistics reports and other sources. IFALPA is concerned that the rates of occurrence of incidents are higher than the aviation industry admits, and for some models of plane are significant. IFALPA supports full reporting and follow up investigations in accordance with all Regulatory requirements as well as medical investigations for those exposed.

As indicated by manufacturer information and industry documentation, materials used in aviation such as jet oils and hydraulic fluids are hazardous and contain toxic ingredients. If such fluids leak into the cabin, toxic exposures are possible. IFALPA is concerned about such exposure events, and supports industry, Government and inter Government initiatives to reduce such incidents.

IFALPA regards the presence of symptoms commonly associated with exposure to airborne contaminants in crew and passengers as a flight safety and health issue.

Corrective actions regarding air supply contamination involving design, operational and maintenance procedures are few, with there being a clear need to review all aspects so as to reduce the intensity and frequency of future exposures.

IFALPA is also concerned that the health implications both short and long-term, following exposure to contaminants being reported by crew and passengers must be properly addressed.

For the reasons above, IFALPA policy recommendations are:

· All aircraft air supply contamination occurrences to be regarded as flight safety & health issue

· All aircraft air supply contamination occurrences to be seen as aircraft defect with all regulatory requirements to be adhered to including: defect report & occurrence Incident report

· All aircraft air supply contamination occurrences involving smoke and or fumes require the use of the emergency/abnormal checklist for smoke or fire & the crew to don oxygen masks at 100%

· Adoption of specific in flight fume/odour occurrence report listing crew effects, aircraft defect and log number, linked to ongoing health examinations

· IFALPA to urge National Regulatory Authorities to review all aspects of air contamination by oil lubricants and hydraulics and applicable Regulations and subsequent actions to ensure all are met

· IFALPA urges that suitable research is to be undertaken investigating: exposure to all air supply contaminants during abnormal oil/ hydraulic and other fluid leakages in aircraft environment, with multiple acute and long term low dose exposures, occupational health and safety aspects on short and long-term basis, medical testing to be undertaken.

· Precaution & prevention principle to be considered for air supply contamination

· IFALPA urges Regulator’s to work with industry to reduce the occurrence of exposure events

· IFALPA is urged to provide member organisations with overview of exposure to air supply abnormal leakages.

AIRCRAFT AIR SUPPLY CONTAMINATION

Introduction

Aircraft materials such as oil lubricants and hydraulic and de icing fluids while usually retained in the engines and equipment to which they have been added, sometimes find their way into cabin air supply through abnormal events such as oil leaks, seal and bearing failures as well as fluid ingestion by engines and APU’s. Crew and passenger exposure to such events via the aircraft bleed air supply as evidenced from defect, incident and fume reports is a growing concern and medical concern for crews and passengers.

This paper aims to raise the awareness of some of the issues surrounding these abnormal aircraft contamination events with the objective of developing strategies to be undertaken by IFALPA and industry.

Issues with regard to incidents of contamination of Cabin air

While concerns of the toxicity risks of cabin air contamination by hydraulics and lubricants extend back to at least 1953,[1] actual reports of crew inhalation exposure to synthetic lubricating oil go back to at least 1977.[2]

While reporting of fume exposure incidents is mandatory under defect and incident reporting systems there is evidence that these are not being utilised as required with little intervention from aviation regulators. The Australian Senate Inquiry into cabin air quality noted “… strong evidence of a tendency of pilots to under-report incidents”.[3] Additionally it can be seen that there are strong discrepancies in the number of fume/ odour reports acknowledged by the regulatory authorities as well as those reports being passed from the operator to the Regulator.

Appendix 1 lists some of the known fume and or smoke incidents/events and crew issues related to oil, hydraulic and other aircraft fluid contaminants from the following sources:

· CAA - Civil Aviation Authority, UK MOR (Mandatory Occurrence Reports) and general information provided

· CASA - Civil Aviation Safety Authority, Australia

· International Air Safety Investigators Bureaus

· Australian BAe 146 aircraft technical log defects - mandatory

· Australian BAe 146 odour Occurrence reports - discretional

· AFA - American Flight Attendant Association - fume occurrence reports - discretional

· International research

· Union surveys

· Industry documentation - service bulletins, service Information leaflets, engineering releases etc.

· Military reports

· Pilot medical certificates

· Air crew public submissions to Inquiries into aircraft cabin air quality

While the UK CAA has advised that air contamination from smoke or gas leaking into aircraft cabin air is rare at approximately one event per 22,000 flights (128 incidents out of 2.85million flights in 10 years to 1999), the DTLR recently advised that smoke/odours/fumes reports on UK aircraft numbered 81 in 1996 and rose to 156 in 1999 and 124 reports to November 2000.[4] The CAA Mandatory Occurrence reports list 50 reports of smoke and fumes related to aircraft contaminants from 1989 to mid 2001 for the BAe 146 and 31 such reports for the B757 from 1997 to 2001. These types of inconsistencies are common in this data.

CASA lists 20 defect reports on its web site related to smoke and/or fume contamination and related issues for the BAe 146 from 1996 to 2001.[5] The Australian Transport Safety Bureau lists 18 incidents of oil fumes for the BAe 146 from 1991 to 2001 with a total of 35 oil fume incidents on jet aircraft in the same period.^3,[6] During the same period, Ansett Australia acknowledged (mandatory) aircraft technical log defect reports of fume-odour occurrences every 66 flights BAe 146 flights in 1992 (418 reports), decreasing to one in every 131 flights in 1999 to June 30 (168 reports),[7] based on a fleet of 13 aircraft.³ At the same time there were over 700 BAe 146 discretional odour occurrence reports from 1991- 2000.³

The number of reports received by the Regulators and Aviation Safety Investigation Bureaus appears to be increasing, which may in part be due to increased awareness of the requirement to report fume and odour occurrences from the cabin air supply.

While the ATSB took two years to produce the occurrence report on a 1997 BAe 146 incident,[8] the Swedish Investigation Board and UK AAIB still have not produced reports into serious BAe 146 incidents in November, 1999 and November 2000 respectively.

Another very important source of information indicating the existence of the problem is industry supplied service bulletins, service information letters and engineering releases. While this information has not been readily available and was not supplied to the recent Australian Senate Inquiry looking specifically at the issue of air quality issue of the BAe 146 aircraft, it demonstrates that bleed air contamination and oil leaking into the air supply and related issues has been an issue since at least 1984, continuing through to 2001. This information may be available from the aircraft, engine and APU manufacturer and should cover ATA sections including ATA 21, 36, 49, 53, 71, 72, 75 and 79.

Additionally, there is a considerable amount of data available from independent research as well as union surveys reporting crew health problems associated with aircraft air contamination. This data has been available since at least 1983 with a growing number of more recent surveys showing very similar symptoms.

Based on various sources, it is estimated that at least eighteen pilots in four counties have either lost their medical certificates, had long-term time off work or are currently off work with problems connected to air contamination. Publicly available information is difficult to collect; many affected individuals are reluctant to provide information and maybe unaware where to provide such information six pilots and six flight attendants are publicly referenced in the Australian inquiry into air quality on the BAe 146 regarding health effects experienced. In one case all three flight attendants off a 1994 BAe 146 flight resigned due to illness.³

Issues with regard to air supply contamination

While oil lubricants, hydraulic fluids, de-icing fluids and jet fuel should be retained in the engines and equipment to which they have been added, they are known to find their way into the aircraft cabin air supply where crew and passengers are located. Exposures may be either short-term intense or long-term low level.

Sources of exposures include:[9]

§ Ingestion of exhaust from other aircraft or recirculation from the aircraft itself on ground

§ Hydraulic fluid leaks can introduce contamination into APU inlet in certain aircraft

§ Excessive use of lubricants

§ Oil and hydraulic fluid ingestion

§ Internal contamination by synthetic lubricating oil- during use of engines/APU

§ Contamination downstream of source of oil leaks –residual contamination

§ Pack burns

§ Engine combustion products

Other information indicates further sources of exposure

§ Leaking oil seals associated with bearings of jet engines[10] ^{[11], [12], [13]}

§ Exposure to thermally degraded oil and it’s by-products[14]

§ Exposure to engine components such as seals/bearings that have worn down into respirable particles containing toxic elements such as nickel, beryllium and copper entering bleed air.¹⁴

Some industry recognition of the sources go back many years and include the some of the following sources shown in Appendix 2.

Issues regarding toxicity of aircraft materials

The aviation industry has a specific need for specialised materials. These can be hazardous. Appendix 3 covers these issues in more detail, but covers:

· oils and hydraulic fluids used in airplane engines are toxic, and specific ingredients of oils are irritating, sensitising, neurotoxic and carcinogenic.¹⁴

· Information provided by oil manufacturers to airplane manufacturers understates the toxicity of their oil products, and this has been accepted uncritically by airplane manufacturers and airline operators and is used by them in a manner that understates risk.

· Specifically, publicly available information on the ingredients of the widely used synthetic commercial engine oil Mobil Jet Oil II:

§ discloses hazard information on one neurotoxic isomer of tricresyl phosphate (TOCP);

§ does not disclose information on the other five neurotoxic isomers, which are up to ten times more toxic and present in concentrations thousands of times higher than TOCP;

§ identifies the ingredient Phenyl-alpha-naphthylamine without disclosing it is a sensitiser.

· If oil leaks out of engines, this contamination may be in the form of unchanged oil, degraded oil from long use in the engine, combusted oil or pyrolised oil. If hydraulic fluids leak from where they are contained, this contamination may be in the form of unchanged fluid or degraded fluid from long use in the aircraft.[15] This contamination may be in the form of gases, vapours, mists and particulate matter.

· Prominent components of the types of contaminants reaching the cabin include: carbon monoxide, volatile organic compounds, organophosphate compounds, toxic combustion and pyrolysis products, and so forth. A number of these are associated with neurological and neuropsychological symptoms of toxicity.[16]

· Contrary to attitudes in the aviation industry, a leak of an aviation fluid into a passenger cabin is not a “normal condition”. It should be regarded as an abnormal condition[17], and treated accordingly.

· All studies that have been carried out to measure atmospheric contamination in airplanes by engine oil leaks or hydraulic fluids are sufficiently flawed on methodological inadequacies to render their conclusions invalid.[18]

· If oils leaks out of engines or hydraulic fluid is ingested into bleed air and is passed to the flight deck and passenger cabin, exposed crew and passengers do not have access to appropriate information that can advise them as to hazard, risk or control of exposure. Additionally exposure may occur to contaminants that can affect crew and passenger health and safety.[19]

· The use of exposure standards such as threshold limit values to conclude that exposures are acceptable is inapplicable in certain situations in the aviation industry. TLVs should not be applied at altitude,[20] or in situations where the possibility of escape to fresh air is lacking.[21] Acceptability criteria for chemical exposures at altitude must consider the interaction of reduced oxygen, skin exposure to mists, and interactions with other contaminant exposures.^20,21

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