Airline Pilot Central Forums - 757 Crews Are “Fuming” Over Poor Cabin Air Quality

[FONT="Lucida Sans Unicode"]Has anyone had this experience on a 757?
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Smoking Out Your Pilots
757 Crews Are “Fuming” Over
Poor Cabin Air Quality
The 757 is starting to stink again. Pilots are leaving freightcarrier DHL/EAT
(European Air Transport) in increasing numbers, citing the 757’s recurring oil-fumes problem and concern for their health as their prime reasons. The history of the cockpit fumes issue goes back several years. British Airways pilots were the first to evince health concerns, in 2003. By mid-2004, a dossier of safety reports filed by British Airways pilots appeared to reveal a disturbing catalogue of noxious engine fumes leaking into the flight decks of their passenger jets.
By October 2004, the problem was in the process of being made to “go away”. According to
BA, “Investigations carried out in conjunction with the Civil Aviation Authority found there were no health implications associated with these fumes.”
Similar problems were being cited on the BAe146 aircraft and were attributed to deteriorating
engine and Auxiliary Power Unit (APU) seals, allowing synthetic engine oils to enter the
cabin air compressors. Engine compressor bleed air is used to drive these compressors. When used for cabin pressurization, the air from the engine must first be cooled (as it exits the compressor stage at temperatures as high as 300°C), by passing the bleed air through an air-to-air heat exchanger cooled by cold outside air. It is then fed to an air conditioning unit which regulates the temperature and flow of air into the cabin, keeping the environment comfortable. The high temperatures of the bleed air and the partially burnt (i.e., pyrolyzed) oil are alleged to be the cause of the oil’s breakdown into its toxic aerosol
components. BA’s problem 757’s were sold off to DHL/EAT and converted to 757SF freighters). That ploy resolved the possibility of any passenger law-suits. At that point, the documentation listed 144 incidents in the past five years, a rate of one per fortnight.
The problems suffered by pilots and cabin crew during flights on Boeing 757’s included dizziness, disorientation, nausea, tunnel vision, slurred speech and incidents of becoming “incapacitated”. You can read about the alarming incident of flight BU925 when both pilots were overcome by fumes during an approach to Malmo Sweden at this link (tinyurl.com/3aromm).
In at least 35 cases, pilots had to don oxygen masks. Earlier, in 2002, 26 Alaska Airlines flight attendants who’d claimed bad cabin air on MD-80 jets made them sick, lost a court case. A jury found “no case to answer”.
A flight attendants group had previously settled a suit against Alaska Airlines for a reported $725,000, giving each plaintiff about $4,000. The remainder went on legal fees.
In July 2006, the U.K. government-appointed Committee on Toxicity (COT) held a public hearing on claims that hundreds of crew had been affected by fumes seeping into pressurized cabins mid-flight. These included a number of cases of pilot and flight attendant incapacitation. The British Airline Pilots Assn. (BALPA) had compiled a database of 770 contamination reports
over the past 20 years, including 262 between 2001 and 2005 alone. The union also believed that crews were “underreporting” incidents for fear of recriminations, while many were just unaware of the insidious effects of cabin air contamination. BALPA, claiming the fumes caused “significant flight safety issues”, is waging a campaign to have its findings taken seriously by the regulator.
The union had collected evidence of health problems among its members, including problems with skin, digestion, breathing and nervous systems. The symptoms range from short-term afflictions, such as headaches and nausea, to more chronic neurological disorders. The April 25 BALPA bottom line on the ongoing fumes inquiry is at tinyurl.com/ypdd5j.
The chemical name for the dangerous airborne ingredient is triorthocresyl phosphate, more commonly known as TCP. It is an additive of engine oil used in commercial aircraft. These oils are highly specialized synthetic lubricants. Research has shown that when they reach a very high temperature, as they do on takeoff or landing, they break down and give off hazardous compounds like TCPs.
These chemicals are part of the family of organophosphates, similar in structure to pesticides. For years, they have been linked to long-term chronic health problems. Crop-dusting pilots are known victims of such habitual exposure. DHL Air has the RB211-535C engines on their aircraft. British Airways had already had a lot of problems with these engines, a problem that continues with DHL Air and EAT. This is apparently compounded by the lack of spare engines of this type. It’s not known why lower levels of reservoir oil could be a solution, but it’s the only one being trialed. You get the impression that the issue is being “papered over.” It’s perhaps small wonder then that the 787 Dreamliner’s design will be addressing bad cabin air from the get go.
Dan Adamek, manager of Aerospace Engineering for Donaldson, states, “The Donaldson
Air Purification System removes gaseous irritants and odors from the aircraft cabin, as well as allergens, bacteria and viruses.”
Mike Bair, vice president and general manager of the 787 program, adds, “The airplanes will have very clean air thanks to HEPA filtration which removes particulates from the air. The 787 will be the first commercial jetliner to have this new gaseous filtration technology for even cleaner air.” The 787 system will feature:
• Bleedless turbofans, allowing elimination of superheated air conduits normally used for de-icing, aircraft power, cabin air and other functions. These systems are to be replaced with an all-electrical system.
• Cabin air will be provided by electrically driven compressors (i.e., no engine bleed air).
• Higher humidity will prevail in the passenger cabin because of composites (which do not corrode). Airbus has conceded that a problem exists with Volatile Organic Compounds (VOCS) in cabin air. In a December 1996 edition of the company’s magazine FAST, Airbus examined the air quality issue. In a later document (tinyurl.com/2asdf8), Airbus announced it was developing a new catalyst to remove both ozone and VOCs. The company’s justification? Health, being a potential liability issue, doesn’t get a mention. The motivation is merely to remove the unpleasant ingestion of taxiway fumes during the queuing for takeoff:
Talking about the problem won’t make it go away, but evolutionary design can. Meanwhile, those who are stuck in the fume “rut” will still have to make malodorous career-versus-health choices. .