Aircraft Engine Fumes

Incapacitation of the flight crew in any aircraft can have fatal consequences. This nearly happened on a Swedish commercial flight when 73 passengers were found deeply asleep and difficult to wake up. Had the first officer or captain not positioned their oxygen masks, literally seconds later they would have passed out.

Hundreds of reports of contaminated air have been filed in recent years and concern the effects of toxic fumes from the engines: aerotoxic syndrome. This potentially threatens all on board the aircraft and has been estimated to affect up to 200,000 passengers every year. This is possibly greatly underestimated, but has allegedly been known as a serious problem to the aviation industry for a long time and is an "open secret" amongst pilots and crews. Apart from the potentially obvious fatal outcome, long-term health issues are apparent from exposure. The publication "Aviation Contaminated Air Reference Manual (ACARM)" by Captain Susan Michaelis (formerly with Qantas) details all known incidents of, and studies into, aerotoxicity. Although the work is considered the leading database of factually sourced information it has allegedly been ignored by the Civil Aviation Authority (CAA) and government. A former pilot (David Hopkinson) had filed a report after a very bad flight on a Boeing 757 ("Toxic fumes on the flight deck") and requested it be sent to the CAA. The CAA claims that it never received it, blaming a 'clerical error'. His licence was taken away for medical reasons (which he blames on toxic air).

In the House of Lords, Lord Bassam (Transport) insisted that there was no cover-up and that only one in some 2000 flights are affected by "fume events". A small issue. But, of the 2.4 million flights in and out of Britain each year, this translates to almost 1200 incidents. Being in command of an aircraft travelling at 600mph and experiencing a sudden memory disruption is certainly no small issue.

And if two pilots are overcome simultaneously in the same cockpit, if such issues can be graded, it becomes

very, very BIG

The Department for Transport (DfT) says it is about to undertake "ground-breaking" research into incidents involving fumes and the Committee on Toxicity (CoT) has allegedly been commissioned to examine the issue.

"The CoT concluded there was (and presumably still is) a need to undertake research on cabin air quality involving a strategy designed to look for the largest number of chemicals. The results of this research would be informative for evaluating the potential adverse health effects associated with cabin air fumes."

Nothing that can be quoted or cited has yet appeared on either the DfT or CoT websites.

Nearly all types of aircraft have been affected by contaminated air, but records (CAA) show that the British Aerospace (BAe) 146, Boeing 757, Airbus A319 and the Embraer 145 seem particularly susceptible. Flybe cabin crew last November (2007) refused to fly on the BAe 146 after 10 leaks of contaminated air in just over a year. The company said it was "completely confident" that its aircraft are "operated and maintained to the highest industry standards" and added that none of its 700 pilots had refused to fly any of its aircraft, but was phasing out the BAe 146 "for green" reasons.

Links between contaminated air and health are not yet proven and "it always has been debatable and still is debatable whether contamination due to oil leaks affects a person's health" (BAe). Since 2003, according to BAe 70 per cent of the fleet had been fitted with a new design of oil seal and "since fitting, we have had no reports of any failures across five million hours of engine operation".

This says nothing of the 30 per cent that have not been modified.

In a patronising comment about flight and cabin crew, "there was an element of misdiagnosis and misreporting".

• Being overcome from fumes can cause death and that is not debatable. In the sealed environment inside an aircraft that is in flight, this is made all the more likely.

Susan Michaelis's research suggests that only four per cent of cases are reported. In 2005, her investigations have revealed that of 265 officially notified incidents of in-flight smoke and fumes on British aircraft, only 35 were claimed in a CAA report to the House of Lords. Over 1660 incidents, mostly thought to be associated with oil-contaminated air, were reported during the careers of 106 BA Boeing 757 pilots. A survey of 250 current and retired BAe 146 pilots found that 85 per cent believed they had breathed contaminated air while flying. Nearly 1 in 10 had to be retired on health grounds.

"There is no way that any working pilot is going to jeopardise his position, so the truth will only come out from retired pilots, crew, engineers and passengers," said Alan Carter, a British pilot of 22 years' experience, who has retired on health grounds. "It is one of the biggest cover-ups in history. If they [airline industry] admitted to this, it would just open the floodgates [for litigation]."

Potentially, without any postmortem examinations such a cause for a crash will never be uncovered, especially as the aircraft will almost certainly be destroyed and no post mortems possible. The downside of this (financially) is that the aviation industry will be harmed by any adverse safety issues. This is a classic case for being played down or even totally ignored. Safety will always come second when there is a cost overhead to consider. The aviation industry appears to be completely immune from climate control issues and the consumption of vast quantities of a petroleum product (kerosene).

A very specious (deceptive) argument could well involve the fact that kerosine is almost exclusively used in aircraft engines. The consumption of oil and the production of carbon dioxide would not enter this argument.

Passengers and crew are breathing air that comes straight from the engines, but little has been done to improve upon this. This system is known as "bleed air" and was installed in 1962. It draws air from the heart of the engine. The (original) alternative was too expensive: air is drawn out of the compression section of the engine and cooled. It then enters the cabin where it mixes with recirculated air that has passed through filters designed to remove bacteria and viruses. This does not remove any fumes or vapours that originate from the engine, so any leaks (faulty seals or over-filled tanks) can contaminate the air supply.

Wrong assumptions can mask the real causes of drowsiness, headaches, flu-like symptoms and nausea. Air can be laced with tricresyl phosphate (TCP), a toxic organophosphate, or other toxic mixtures of chemicals that have been linked to serious respiratory problems, memory loss, neurological illnesses and brain damage.

In the United States, blood testing on airline crews showing the specific antibody that confirms brain damage and cell death is ongoing. The crews had been exposed to contaminated air in airline cabins. Neuro-psychological impairment (related to working on an aircraft) has not been screened by the DfT in Britain. The Federal Aviation Administration (FAA) is worried about under-reporting and provided $2 million funding for further investigation. The US Association of Flight Attendants had recorded more than 800 cases on one airline of flight attendants being affected by contaminated air.

The DfT:

"Until we know what's in the air we can't screen the pilots. Once we have carried out air tests we can move onto monitoring pilots for anything that may affect them."

Screening for a specific 'unknown' is not practical, but looking for ANY chemicals that should NOT be in the air supply is possible. Whatever they may be. Analysis can then identify what they are. It's what analytical chemists and forensic scientists do all the time.