Contaminated Air Events and Flight Safety
Source: Aviation Contaminated Air Reference Manual
Are All Contaminated Air Events Safety Issues? © 10th April 2008 by Susan Michaelis Another issue of major concern is the CAA view that many contaminated air events are not safety related. This cannot be more clearly spelt out than in a response provided in the UK House of Lords in 2005. The Government was asked by the Countess of Mar what it intended to do about under-reporting of contaminated air events given that there was evidence that a 2002 UK survey showed that 96 % of events were not reported. The Government advised:
‘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. The survey carried out by the British Airline Pilots Association included events that were not safety-related.’ [82]
This response was unsurprising given that the CAA had stated the same thing a year earlier:
‘The Civil Aviation Authority compared the British Airline Pilots Association survey results with its mandatory occurrence reports. Much of the survey data related to low level events, often with inconclusive connections to contaminated air. Inclusion of the survey data in the Authority's database would not have advanced or improved the formal intervention action taken to mitigate the threat to safety posed by impairment of pilot performance through exposure to contaminated air.’ [89]
The CAA view is extraordinary given the following points which will be explained in greater detail in following chapters:
Major under reporting and incomplete reporting of contaminated air events is occurring - see Chapter 12;
Contaminated air events are reportable incidents – see regulations in Chapter 15;
The frequency of contaminated air events is not accurately known; however, the evidence available shows it is NOT low;
Any form of crew impairment (adverse effect) is an aviation safety matter;
Adverse effects are occurring other than just incapacitation – see Appendix 2;
Crews are failing to use oxygen during contaminated air events – see Appendix 2.
The following reports taken from Appendix 2 are assumed to be examples of what the CAA might consider are not, ‘safety related.’ Given that pilots are required to be in a fit, unimpaired state of health to be able to deal with normal operations or any abnormal situation that might arise, their view appears negligent and contrary to the actual aviation regulations. The events in Appendix 2 have been collated from various sources including but not limited to the CAA MOR database, AAIB reports, Crew reports (ASR/MOR, FCR, direct to union…). They are all reports that the crews felt sufficient to record in one format or another even if they represent less than 4% of all events as will be discovered in chapter 12.
4-Jun-2000 B757 - Fumes throughout flight - Tunnel vision, disorientation, dizziness on arrival - engineering reported long history of fumes - Crew declared sick on arrival and positioned back to LHR as no medical facilities available
27-Apr-2003 B757 - Oil fumes
19-Dec-2004 A319 - Perceptible oil smell in flight deck / oxygen not used
3-Jul-2005 BAe 146 - Complete oil loss - smelt by several crews - P1 said ‘normal BAe 146 smell' - P2 ill still weeks later - P1 suffered effects later - 3 engine ferry next day
4-Aug-2005 Dash8-400 - Oil vapour / chip fat fryer smell – Oxygen - priority landing - ‘fumey on previous sector’ - Paramedics (blood pressure and pulse only)
17-Aug-2005 BAe 146 - Flight crew effects reported yet no apparent fumes
26-Aug-2005 A319 - ASR / MOR - Perceptible oil smell in descent from 10,000 feet to touchdown only flight deck. Oxygen not used.
1-Sep-2005 BAe 146 - ASR - Abnormal Air Conditioning smells - engineer advised fumes smelt but could not find where from - Aircraft grounded - ‘Engineering inspections found no fault’ - During operations with the APU unserviceable, a smell, described as similar to 'damp socks' was intermittently evident in flight deck - Flight Crew discussed going onto emergency oxygen but decided that this was unwarranted - No defect was recorded after flight / similar circumstances during the subsequent flight with the same crew - low risk.
7-Sep-2005 BAe 146 - REF MOR 200507452 - same aircraft as following day - cabin crew experienced similar symptoms (light-headedness and slight confusion) and had found normal tasks difficult to achieve.
15-Sep-2005 B757 - Strong oil fumes - Oxygen not used as aircraft had a long history over several months and assumed must be safe or aircraft, ‘would not be flying.’ Pilot advised most pilots were not writing it up and just telling the engineers about the smells and told all OK. Captain had headache - muscular and significant gastrointestinal problems since event - Unaware of need to use oxygen in all cases of contamination or suspected contamination - ASR raised to cover medical effects.
6-Oct-2005 BAe 146 - Crew effects / no apparent fumes.
1-Nov-2005 B757 - Transient fumes in flight deck - Technical log signed off to report next sector.
29-Nov-2005 B757 - ASR / MOR - No Oxygen used - Cabin crew all suffering effects even with left pack inoperative. See previous sector.
Additionally, the CAA view is astounding given that it is acknowledged that monitoring studies of the air quality during contaminated air events have never taken place. Some of these important statements include:
UK Aircraft Health Working Group - ‘Air Sampling has never been done during a fume event.’ [90]
UK Government - ‘There is no requirement for air quality monitoring exercises to be carried out during contaminated air events in aircraft, and there is no record of any such measurements in the public domain.’ [81]
National Research Council - ‘No published reports include measurements of air quality during flights involving non routine events such as leaks of hydraulic fluid or engine oil into the bleed air.’ [91]
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
81. Countess of Mar HL Question in the UK House of Lords. Question number: HL 2312. 1 December 2005. ‘There is no requirement for air quality monitoring exercises to be carried out during contaminated air events in aircraft, and there is no record of any such measurements in the public domain. Air quality measurements are normally only made as part of the initial certification of each aircraft type.’
82. Countess of Mar HL. Question in the UK House of Lords. Question number: 2311. 23 November 2005.
89. Tyler P. MP. Question in the UK Commons. Question number: 191638, 18 Oct, 2004.
90. Summary report of the UK AHWG RSG meeting of 13/7/05.
91. National Research Council: The airliner cabin environment and the health of passengers & crew, 2002.
