The Airline Pilots Forum and Resource

THE AIRLINE PILOTS FORUM & RESOURCE

Contaminated Aircraft Air Flight Safety and Crew Report

Source: Aviation Contaminated Air Reference Manual

Reporting Contaminated Air Events © 10th April 2008
by Susan Michaelis

Crews should enter contaminated air events in the aircraft maintenance or technical log. Crews may also report problems through official regulator reports or national flight safety bureaus such as the following: in the UK an Air Safety Report (ASR) or Mandatory Occurrence Report (MOR) and direct to the UK Aircraft Accident Investigation Bureau (AAIB); in Australia an Air Safety Accident or Incident Report (ASAIR) formerly called an Air Safety Incident Report (ASIR); or in the USA through the National Transport Safety Board (NTSB), the Aviation Safety Reporting System (ASRS) or Service Difficulty Report (SDR). A problem that exists sometimes, is that the crew will file a report with their airline and expect it to end up on the regulator database but for whatever reason this never occurs. As an example a UK B757 pilot reported ‘toxic fumes’ in the flight deck in 1998 via the MOR system and requested his airline to submit it to the CAA. However, almost 8 years later it still had not been sent to the CAA as required. [40][41] Crews can also make internal company reports such as Flight Crew Reports, ‘BAe 146 odour occurrence report’ as was the case at Ansett Australia or, a ‘Safety Occurrence Report’ as used at National Jet Systems in Australia or an ‘Employee Accident Report’ as they had at Alaskan Airlines in the US. Crews can make oral or written reports to their unions, colleagues, anonymously through pilot internet forums such PPRUNE (www.pprune.org), through pressure groups such AOPIS (www.aopis.org) or through industry confidential reporting programs like The Confidential Human Factors Incident Reporting Programme (CHIRP) in the UK or Aviation Self Reporting Scheme (ASRS), formerly known as Confidential Aviation Incident Report (CAIR), in Australia. Data can also come from the media or published formal investigation reports of incidents by the National Air Accident Investigation Branch, such as the Air Transport Safety Bureau (ATSB) in Australia, US NTSB or the Transportation Safety Board of Canada (TSB).

Exposure to contaminated air has caused many significant incidents over the last 40 years. Chapters 8, 9, 10 and 11 look at some of the official inquiries and in the Appendices we list:

  • Appendix 2: Incidents on the UK database as of 1 August 2006;

  • Appendix 6: BAe 146 Contaminated air events given to the Australian Senate by the FAAA;

  • Appendix 7: USA Contaminated air events as of 18 August 1997 listed in a NIOSH HHE application.

However, these are just the tip of the iceberg as they will be just a small example of what is going on. This book is not large enough to list all the events we know of, and we only know of a very small percentage of the global picture. It is important to read the events listed closely, as there is a lot of pertinent detail in them that shows how the system is failing and how this is a major flight safety issue. Some sample known contaminated air events examples are given in List 1.


List 1: Sample Known Contaminated Air Events

22 January 1986
Australia - Inter office memo
British Aerospace BAe 146

Prior to departure crew advised of possible cabin smoke associated with APU bleed air for air conditioning… Cabin crew and passengers showed discomfort due to irritating smoke. Cabin filled with smoke again after engineering cleared aircraft fit for flight with MEL applied (long-term health effects advised).


29 July 1989
United States
MD80 (SEA / SNA)

Shaky / hands numb / pale / headaches / shortness of breath / disorientated / toxic exposure / not CO poisoning / routine until mid flight / cabin air was heavy.


28 September 1991
United Kingdom Air Safety Report / Mandatory Occurrence Report
British Aerospace BAe 146

Passengers and crew suffered nausea and headaches. APU found to be blowing oil.


6 March 1992
Australia - Ansett Australia internal engine defect report: Engine no.210, VH-EWS
British Aerospace BAe 146

Oil smell in cabin. APU removed with front compressor bearing seal carbon insert cracked… Oil filler cap locking pin was broken which cocked the cap, allowing oil to leak past the seal. Exterior of the APU was contaminated with oil that had leaked from the oil filler cap. The oil had been reingested into the inlet plenum combining with the oil leak past the compressor seal, causing the oil smell in the cabin. This is an ongoing defect with investigations continuing (long-term health effects advised).


18 November 1994
Ansett Airlines Odour Occurrence Report
British Aerospace BAe 146 - JJS 488

Fumes in cabin. Crew suffered burning eyes, shortness of breath, nausea, headaches, sore throat, swollen glands and fever. Flight attendants in the rear cabin on emergency oxygen (long-term health effects advised in all 3 cabin crew).


9 March 1995
United States
B737-400 (PDX / BUR / SEA)

Headache, nausea, lethargic / confused / inability to concentrate. Strong solvent like odour.


6 February 1996
US FAA
Airbus A320

Smoke and fumes in the cockpit and cabin. Air Cycle Machine replaced.


3 May 1997
United States
MD80

Confused / light headed / tired / headache


8 November 1997
Australia - General Flight Report
British Aerospace BAe 146 - VH-JJW - Ansett flight 407

On all 3 sectors the flight attendants complained of feeling waves of nausea and weakness after take off and on descent with change of pressurization and air selection. Nil fumes smelt. Engineering records for 9/11/97 show Number 2 bleed inlet duct and both sleeves on air cycle machine replaced. Duct cracked and hoses leaking. ATSB CAIR report notes oil fumes and adverse effects experienced by crew over 3 day tour of duty (6-8 November, 1997) including the following comment from the cabin Purser:

‘I took my seat for landing and I felt this heat come from the top of my head following down over my chest, followed by this intense pressure from above the top of my head following down over to my chest, then it felt like all my strength was being sucked out of my body through my head. I was having nausea waves and felt extremely tired… I was having trouble breathing and battling to stay awake. The heat and pressure happened 3 times. When I went to move my arm I was paralyzed, I couldn’t move anything, then we touched down and it lifted. When I finally felt I could use the P/A my speech was slurred and I couldn’t get the words out, my eyes were bloodshot and I was very pale and felt very exhausted… I had trouble walking to the terminal.’

Similar symptoms occurred on next sector from Ayers Rock to Perth. Passenger reports available from 3 passengers reporting adverse effects on same flight. [42]


24 November 1997
United Kingdom Air Safety Report / Mandatory Occurrence Report
British Aerospace BAe 146

Strong smell of fumes causing severe crew discomfort. All crew experienced strong stinging of the eyes and nose, dryness to the throat, headache and breathing problems. Source found to be oil from the Number 1 bearing oil seal entering the bleed air system.


30 April 1998
US Employee Accident Report
MD80

After landing smell of burning odour in cabin. Experienced burning sensation in eyes, throat, face and skin flushed with a lot of difficulty breathing - felt ‘out of it’.


1 June 1998
Australian Air Transport Safety Bureau
Airbus A320

Dirty sock odours reported prior to departure and during flight. Maintenance log had report also on previous sector. Two Flight Attendants had to sit down as faint and light headed.


21 January 1999
United Kingdom Air Safety Report / Mandatory Occurrence Report
British Aerospace BAe 146

Flight deck crew incapacitation - possibly due to fumes on flight deck. First Officer (FO) reported blurred vision, tingling in fingertips and a lack of concentration and requested that Captain assumes control. FO’s face was white with lips discoloured and pupils dilated. Capt felt light-headed with tingling in fingertips.


8 February 1999
Australia - Ansett Airlines maintenance log reference 959625
British Aerospace BAe 146 - VH-JJT

Odours detected in cockpit on 3 out of 4 sectors. Odours occurred after air changeover, after take off and on engine shutdown. Could not isolate source. Engineering: Engine no. 1 does emit oil odours. MEL applied to air conditioning system (cleared for further flight). BAe 146 ‘cabin log odour occurrence’ report notes that the Captain and First Officer both experienced headaches, nausea and slight dizziness.


9 February 1999
Australia - Ansett Airlines.
Maintenance log reference 959627
British Aerospace BAe 146 - VH-JJT

Odours detected on last 3 sectors especially during air changeover, on take off, on ground and during climb. Engineering: Cockpit filter found very dirty. Cabin filter found crushed and expanded due to excessive contamination allowing contaminated air to bypass deformed filter.


1999
Typical report to AOPIS

Crew reported an odour at the departure gate. The pilot turned off the APU and the plane departed. Odour persisted throughout flight. All attendants experienced symptoms including: burning eyes, disorientation, headache, difficulty breathing, dizziness, burning lips, drowsy, stomach cramps, rapid heart rate & hot & cold sweating. On landing all flight attendants released from duty. Pilots suspected contamination of # 2 pack.


12 February 1999
Australia - Ansett Airlines Odour Occurrence Report
British Aerospace BAe 146

Crew were hot, tight chested and light headed. Purser on Oxygen. Later nauseous. First Officer had to sit in terminal after flight to recover.


1999
Typical report to Author

Prior to departure, there was a dirty sock odour. The taxi, climb and initial cruise were uneventful, however in flight there was a strong odour and the F/As and some passengers were symptomatic. The F/As donned oxygen masks. All F/As went to the hospital on landing. Symptoms reported by F/As included: headache, burning eyes & nose, disoriented and shortness of breath, sleepy, confused, pale, tingling lips. Number 4 engine was believed to be leaking oil into the air supply.


September 1999
Canada (via AOPIS)
Passenger comment

Flight attendants and passengers complained of contaminated air smells. Symptoms reported were headaches, confused state and tingling.


10 November 1999
Canada - WCAT 2006-02748- AD
Dash 8

On the first of two flights the worker (flight attendant) worked on that day (on the same aircraft), she smelled a strange odour from the time of engine start-up. She reported this to the captain, who undertook to monitor the situation on the flight. As far as the evidence reveals, no one else (crew or passengers) was bothered by this odour on this first flight. On the return flight, however, other crew members are documented by an employer incident report as having experienced headache and light-headedness; no smoke was visible and the crew did not have problems with their eyes, throat or nose. This flight was cleared for a “short final” landing. On arrival, this worker reported a severe headache, dizziness, a racing heart, numbness of her upper lip and face and nausea. A hydraulic leak was suspected by the crew. When the airline had the aircraft checked, it was confirmed that the smell was coming from the number one bleed air system. The oil tank was found to have been “over-serviced” the previous night; on running the engine with “full hot selected” the smell dissipated after approximately 10 minutes. It was noted the bleed air duct had been replaced the previous day, and coating on the new duct was suspected as the cause of the fumes.


18 January 2000
Australia - Ansett Airlines Odour Occurrence Report
British Aerospace BAe 146

Noticeable oil fumes on 2 sectors including in the cockpit in the climb. Cabin crew advised feeling nauseous during descent on 2 sectors with several passengers vomiting on approach into Alice Springs. Maintenance log reference number 049046.


31 March 2000
Ansett Australia ATSB incident report number 200001175 - VH-JJZ and evidence given to Australian Senate Inquiry [43]
British Aerospace BAe 146

When switching air supplies from the APU to the engine air supplies, we got this odour in the cabin - I call it the dirty sock smell. I have smelled it numerous times in the past… about a minute later, I felt just a slight light-headedness coming about, so what I did was I took the oxygen mask. I did not actually properly don it; I just took it and held it up to my face - at that point the autopilot was already on - and just took a few whiffs to sort of clean my system out. It is pretty much standard procedure and it is there at the ready in case you need it. What happened, as I pretty much expected it would, was that the symptoms of this sort of lightheadedness went away pretty much straightaway… the light-headedness thing sort of came back again and a very, very dull headache transpired, so I started breathing the oxygen again. Lo and behold, it started to go away and, as the flight progressed - and once again I was not breathing oxygen the whole time - it went away and then it started coming back again. And then later I just had very dry scratchy eyes, a sore throat, that sort of thing, a taste in my mouth, and the only way I could describe it is it tastes like it smells. So at this point I am already saying, ‘There is obviously some sort of a problem here we are going to have to sort out but, once again, what engine is it coming from, what pack is it coming from?’ There was really no way of telling because there was no way to isolate it. So the flight continued and, on descent at the lower altitudes going into Melbourne, I then became aware that with the points of light, when you get down low at night - it was a very clear, brilliant night - there was some blurring in my long-distance vision… It was not until that point, in walking across the ramp at Melbourne, that I realised that I had a slight disorientation. I do not really know how to describe it - not staggering, falling over drunk, but it was very obvious that there was something wrong, that there was a minor incapacitation.


11 July 2000
United Kingdom Air Safety Report / Mandatory Occurrence Report
Boeing 757

Crew illness and incapacitation. Oily metallic smell evident on flight deck. Flight crew partially incapacitated, numerous Air Traffic Control (ATC) calls missed. Evident during previous sector – ATC reminded pilots to slow aircraft down at 3.7 miles from touchdown. Crew unaware they were becoming partially incapacitated.


11 and 13 December 2000
United States B747-200 Flight - SFO-NRT-SFO (North West Airlines)
Excerpts from Workers Compensation Deposition

About four hours into that 11-hour flight from San Francisco to Narita on December 11, 2000, the flight attendants started to experience dry burning eyes, bad headaches, and nausea. An unusual number of passengers were also complaining of nausea, vomiting, and headaches. The symptoms were documented in an incident report written by the lead flight attendant. During that flight, the Applicant recalls that she had felt well enough to complete her duties, but had felt unusually fatigued upon arrival. That night, aircraft #6635 flew from Narita to Seoul, Korea with a different crew. Crew advised that aircraft's ozone converters had failed. On the night of December 12, 2000, all three ozone converters were replaced in Seoul. During that December 13, 2000 flight from Narita to San Francisco, the flight attendants and passengers again reported symptoms. During her deposition, the lead flight attendant described "a lot of people throwing up." All of the flight attendants were reporting bad headaches, nausea, and very dry eyes. Mechanical records confirm that the ventilation ductwork had recently been contaminated with engine oil from an APU that had leaked oil. The mechanics had replaced the leaky APU 18 days prior to the December 11, 2000 incident, but according to the maintenance records, the oil-contaminated ductwork had not been replaced or cleaned.


25 January 2001
United Kingdom Air Safety Report / Mandatory Occurrence Report
Boeing 757

Aircraft refused for service due ongoing history of toxic fumes on the flight deck. Open technical log defect report regarding strong oil smell during last few sectors (both crew unwell some days before) with aircraft cleared for further service / report with a suspected intermittent oil seal.


29 April 2001
United Kingdom Air Safety Report / Mandatory Occurrence Report
British Aerospace BAe 146

Cabin crew incapacitation due suspected fumes from APU.


27 July 2001
Canada - Internal Company Incident Report
Boeing 767

Immediately after take off there was a very hot oil smell throughout cabin which lasted for 20 minutes but was very strong for 10 minutes.


29 July 2001
Australia - Internal Safety Occurrence Report
British Aerospace BAe 146

Very strong and noxious overwhelming fumes and symptoms reported in flight deck and cabin. Passengers disembarked. Request to change crews (pilots and FA’s) was denied as crew considered by airline to be ‘medically fit’ to crew the flight.


August 2001
Australia - CASA Service Defect report - ALF 502R engine (BAe 146)

No 1 engine No 9 bearing seal leaking. Suspect fumes entering cabin and causing crew problems.


4 September 2001
United Kingdom Air Safety Report / Mandatory Occurrence Report
Boeing 757

Metallic chemical taste and smell in flight deck atmosphere. Flight crew felt ill effects in flight but were incapacitated on ground. Captain felt slightly ‘euphoric’, ‘light-headed’ and ‘uncoordinated’ on final approach and taxi in. Both pilots felt unwell during turnaround and did not operate return sector.


22 September 2002
United Kingdom Air Safety Report / Mandatory Occurrence Report
Embraer EMB145

Strong smell of burning oil on flight deck and in the cabin from residual oil contamination following replacement of engine and APU. All crew had headaches, sore throats and coughing.


November 2002
Australia - CASA Service Defect report - ALF 502R engine (BAe 146)

No 1 engine fumes entering cabin. Limited information provided.


28 November 2003
United Kingdom Air Safety Report / Mandatory Occurrence Report
Boeing 757

Transitory fumes on flight deck. Slight fumes detected on start up. Both pilots used oxygen during descent as Captain was light headed and First Officer had tingling in fingers and lower arm.


4 October 2004
United Kingdom Air Safety Report / Mandatory Occurrence Report
Embraer EMB145

Fumes and grey / haze mist in cabin reported by cabin crew and passengers. Emergency declared and oxygen used. Precautionary medical checks for crew.


2 November 2004
United Kingdom Air Safety Report / Mandatory Occurrence Report
Boeing 747

Fumes and suspected contaminated air on flight deck and in passenger cabin. Aircraft diverted. 4 passengers hospitalised as a precaution.


8 December, 2004
United Kingdom Air Safety Report / Mandatory Occurrence Report
British Aerospace BAe 146

Flight crew incapacitation due to possible air quality problem: Co-pilot felt unwell (faint and breathless with shaking hands), oxygen given, Captain had headache with flu symptoms and was in a state of euphoria although successfully landed the aircraft while operating as single crew. Co-pilot sent to hospital and Captain suffered headache and flu symptoms for 24hrs. Incident not entered in aircraft tech log. APU exhaust may have entered air supply. Subsequent investigation found APU Bay covered in soot as were packs and ducting.


23 February 2005
United Kingdom Air Safety Report / Mandatory Occurrence Report
Airbus A320

Significant fumes and mist in rear cabin. Emergency declared. Crew effects in mouth and throat.


15 March 2005
United Kingdom - Report to pilot union
Airbus A319

Oil smell on climb and descent.


20 April 2005
United Kingdom - Report to pilot union
Airbus A319

Slight smell of fumes (burnt oil from air conditioning) was apparent in flight. Engineering found the APU generator oil seal leaking.


12 July 2005
United Kingdom Air Safety Report / Mandatory Occurrence Report
Boeing 737

Air contamination and odour in cabin and flight deck. Co-pilot, cabin crew (light headed dizzy and nauseous) and some passengers affected by fumes. Oxygen given to one cabin attendant with another noted to be distressed. Emergency declared. Co-pilot became light headed but recovered enough to carry out duties on descent. Crew hospitalized as a precaution. Faults found in hydraulic system.


4 August 2005
United Kingdom - Report to pilot union
Dash 8 - Q400

Oil vapour or chip fat fryer smell, oxygen used, priority landing, ‘fumey on previous sector’, Paramedics called.


8 October, 2005
United States - Maintenance records & workers compensation documentation
Airbus A320

Smell noticed on ground before departure that had been delayed 1 hour. Smell intensified after take off. Smoke and fumes stronger at front of cabin. Flight attendants experienced symptoms including gasping for air with difficulty breathing. Advised pilots were on separate oxygen supply. Emergency landing undertaken with fire fighters & emergency crews meeting aircraft upon landing. Maintenance records show pilots reported fumes on several occasions with nil fault found initially with APU starter then later found to be contaminated with oil & leaking onto APU intake. – see Chapter 21.


24 Aug 2006, US Airways Flight No 1025
United States
Boeing B737

Flight diverted from MHT to BOS after nine people sickened by "sulfur like" smell believed to be caused by mechanical/maintenance problems. Pilot, co-pilot, three flight attendants and four passengers experienced nausea and dizziness en route. Pilot, co-pilot, and passengers treated by paramedics. FA taken to local hospital. Crew reported to airline and media broadcast story.


11February 2007
United Kingdom
Boeing 777

Crew comment: ‘I have just returned from CCU this morning on G-YMMB (RR powered aircraft). During the descent into LHR there was a distinct 'oily' smell apparent on the FD, not visible and not strong (subjectively) but present nonetheless. My two colleagues were conscious of it as well. Interestingly, I noticed the same on this aircraft last Thursday on the way out to CCU during the descent on that sector. I made an entry in the tech log this morning to that effect. In some ways it seemed unnecessary but given what appears to be widespread under reporting of fumes events and the current uncertainty over the potential for serious health damage...’ (Oxygen not used) [44]

There are many other sources of data indicating that adverse effects are being experienced in flight. Therefore the association between adverse effects or symptoms and the effect on flight safety is obvious. Just a few such examples include:

  • 1983 study of 683 American flight attendants (95% response rate). Flight attendants flying the DC10-10 and B747 aircraft report high rates of symptoms (eye, nose, sinus & throat irritation / allergic or irritant rhinitis, headaches & chest symptoms…) related to airborne contaminants, including nitrous oxides as well as an unknown chemical mixture characterized as ‘dirty socks odour.’ [45] Clearly such symptoms in flight would prove distracting to a flight attendant in carrying out duties.

  • In the 1990s as reported in the Australian Senate Inquiry, studies undertaken by Professor van Netten and media coverage articles, showed that defects related to leakage of oils into the air supply system was not uncommon in Canada.

  • Allied Signal, the manufacturer of the BAe 146 engine, the ALF502R, experienced engine seal problems with seals 1,3,4,5 and 9 and also engine bearing problems. Many such events were linked by crews to in-flight and post flight health effects after exposures. [46]

  • Just the few basic examples above clearly show the alarming scenario that the aviation industry is currently faced with. A situation born out of a lack of will to rectify the route causes of ongoing engineering defects and much needed crew training. Crews forgetting to lower the undercarriage for landing, forgetting to slow the aircraft for landing, crews becoming incapacitated, passengers and crews suffering exposure symptoms and experiencing various degrees of impairment. While pilots have very strict rules about drinking and flying or taking any medication or substance which might impair their ability in any way to fly the plane, [47] the airline industry, however, fails to stop crews performance being impaired by contaminated air. Australian regulations are very clear that the pilots cannot absorb any substance which could impair their capacity, however, contaminated air is not even considered as such a substance. This impairment is not just a health issue but a serious risk to flight safety not to mention the effects on passengers. When contaminated air events occur, crews and passengers are being exposed like test animals in a cage by an airline industry that knows some will be harmed but seems quite accepting to risk their long term health by turning a blind eye. They should know that some crew and passengers will be harmed as they know for certain that some have lost their medical certificates or jobs already and can fly no longer as will be discovered later. The risks to the safety of flight are clear. The aviation industry claims that there are two pilots and therefore if one is affected, flight safety will not be compromised as there is the second pilot. However, the data in Appendix 2 clearly shows that there are numerous cases where both pilots are affected to varying degrees simultaneously. Additionally, commercial jet aircraft are two pilot aircraft and therefore both should be in a fit state to operate the aircraft at optimum safety levels. Any degree of impairment due to contaminated air is unacceptable from a safety point of view. The same argument is used for emergency use of oxygen. The aviation industry claims it is there and the aircraft is therefore safe during fume events, however, as will be seen later, oxygen is rarely being used.



    Flight Safety Aspects of Contaminated Air



    References

    40. UK House of Lords written question. Lord Tyler [HL 3078] 10 January, 2006.

    41. Email from Captain D. Hopkinson to G. Stockbridge of the DfT 18 January, 2006 & response from A. Ali of CAA division of the DfT to Capt D. Hopkinson, 6 February, 2006.

    42. Judy Cullinane (Ansett flight attendant) 1999. Submission to the Australian Senate inquiry into air safety (1999- 2000) BAe 146 cabin air quality. Parliament of Australia, Canberra.

    43. Captain R. Goulet (Ansett) 1 May 2000, Hansard Evidence to the Australian Senate inquiry into air safety (1999- 2000) BAe 146 cabin air quality. Parliament of Australia, Canberra.

    44. Comment from British Airways pilot seen by the author.

    45. Interim Report #1. Association of Professional Flight Attendants. Report to San Francisco General Hospital Medical Centre. Occupational Health Clinic. 6 September, 1983.

    46. Former UK based engineer communication with the author.

    47. Civil Aviation regulation 1988 (Australia) CAR 256 – Intoxicated persons not to act as pilots etc. or be carried on aircraft - ‘A person acting as a member of the operating crew of an aircraft, or carried in the aircraft for the purpose of so acting, shall not, while so acting or carried, be in a state in which, by reason of his or her having consumed, used, or absorbed any alcoholic liquor, drug, pharmaceutical or medicinal preparation or other substance, his or her capacity so to act is impaired.’


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