Clearing the air

But it seems for a relative handful of pilots and flight attendants nothing much has changed–except for the open window–with a spate of health claims being successfully pressed against airlines that are related in most cases to toxic fumes entering the aircraft cabin and cockpit from tiny oil leaks in engines and APUs. To date, most of the most publicized complaints have centered on a single aircraft type—the BAe-146–although others including the DC-9/MD-80 and 757 have also drawn complaints over air quality from flight crew.

Cabin air technology remains fundamentally unchanged over the last few decades and relies on bleeding air from the engines, cooling it and circulating it into the cabin through passive filters. The system depends on “HEPA” filter blocks and variants through which air is passed to remove particulates. These passive filters are dependant on air being dry-as is cabin air at cruise altitude– for maximum efficiency.

In Australia there have been several successful claims by flight attendants who alleged their health was damaged during their service on BAe-146s operated by defunct Ansett Airlines and East West Airlines in the 1990s.

In one case, settled in May last year, Joanne Turner a flight attendant with East West was awarded $137,757 ($126,736) by the N.S.W. Dust Tribunal. In another case, doctors said the attendant still has long-term health problems, including intermittent breathing difficulties, chemical sensitivity, dermatitis, disorientation and impaired memory, which have left her unable to work.

The BAe-146s entered service in Australia in 1983 with more than 30 in operation during the peak of operations in the late 1990s. The fume problem—which was attributed to leaky engine seals–was first reported in 1991 with a handful pilots and cabin staff saying they had been overcome.

The issue became the subject of a government inquiry in Australia which found that the BAe146 met all certification standards but the government responding to recommendation issued an AD requiring that inspections of oil contamination every 500 hours and established a Reference Group to follow progress and analyze outcomes of international research into the issue of fumes.

More than 60 Ansett flight attendants claimed they could not work on the 146 and were rostered on other aircraft. Interestingly, according to Ansett at the time, part of the problem was that some flight attendants simply did not care for the 146– which was the smallest jet in the fleet.

In 1996, Ansett sought outside medical advice and set up an independent panel, including safety regulators to evaluate air quality. The panel determined that toxic levels on the jets were thousands of times lower than international standards.
However, the problem was somewhat more serious according to one former National Jet System (now Cobham Aviation Services) executive. “It had the potential to ground the fleet,” he claimed.

“More than 60 Ansett flight attendants claimed they could not work on the 146 and were rostered on other aircraft.”

Cobham, now the largest BAe-146 operator in Australia, worked extensively with BAE Systems and the engine maker, AlliedSignal to rectify the engine seal problem. In fact it was NJS engineers that made significant contributions to the ultimate solution. Those new seals have been installed through the fleet since 2004 with over 95% of aircraft upgraded.

However seals were only part of the issue with misreporting by crews and fundamental cleanliness of the aircraft other factors according to BAE Systems. Perhaps the most interesting example of the latter was a Flybe 146 fume event in September 2007 which turned out to be overuse of bleach in the forward toilets. The BAe-146 was operating from Birmingham to Belfast on a repositioning flight and the crew felt lightheaded just after take-off and all donned oxygen masks. According to the UK Air Accidents Investigation Branch (AAIB) report “the origin of the fumes was traced to the forward toilet and was due to a chemical in the toilet.” A spokesman for the airline told British media that too much formaldehyde was used to clean the lavatory during maintenance at Exeter airport.

Although on the commercial side, the issue is most associated with the 146, fume issues have been reported by aircrews on a host of other aircraft including the 757, A320, 737 and ERJ-145, while in military service the C-130 has had its share of complaints. Gauging the extent and seriousness of the problem is as challenging as fixing it. The UK CAA’s database reveals that there were nearly 1,800 reports of fumes entering the cabin from 1985 to July 2006. While a few related to smoke most involved vapor containing engine oil constituents introduced through the engine or APU compressors.

In the first six months of 2009, 38 contaminated air events were reported in the UK out of 553,266 flights. None involved the 146, while eight involved the 757. A total of 97 UK events were reported in 2008 out of 1.2 million passenger and cargo flights. Twelve commercial pilots (out of 20,000 license holders) lost medical clearance for reasons that they attribute to poor cabin air. According to the government, out of 29,000 passenger complaints put to the UK Air Transport Users Council since January 2001, only one has related to air quality.

FAA believes that under-reporting of fume events is an issue, with Director of Flight Standards Service Jim Ballough telling the US/Europe International Aviation Safety Conference last June that, “FAA is becoming increasingly concerned by numerous reports of smoke or gasses on flight decks and in passenger cabins. Our analyses of the data indicate that a large number of such incidents are not reported.”

Last March FAA sent out a Flight Standards Information Bulletin for Airworthiness, requiring the introduction of new reporting routines for incidents involving smoke or fumes in passenger cabins and on flight decks. The emphasis was placed on maintenance personnel to determine whether airlines have adequate procedures for reporting, investigating and following up incidents. FAA wants follow-up and records on every to give the industry accurate data to investigate and monitor development trends.

Former captain Tristan Loraine who is co-chair and founder of the Global Cabin Air Quality Executive has authored a book called Toxic Airlines on the subject. His efforts were in response to a fume event he says occurred in 2006 while in command of a 757.

Former Australian based BAe 146 pilot Susan Michaelis has published an 844-page reference manual covering the issue of air quality called “Aviation Contaminated Air Reference Manual” which has been reviewed and highly commended by the Royal Australian Air Force. The RAAF went further and claimed that there was a “widespread prevalence of denial of the existence of the problem, particularly among the aircraft operators and aviation regulators.”

Michaelis’s work makes some interesting claims such as:
An FAA 2005 report indicates one fume or smoke event from engines for every 10,000 flights;
Less than 4% of contaminated air events are reported;
More than 20% of CA events result in pilot impairment;
More than 9% of CA events result in both pilots being impaired;

The body of evidence to support a problem prompted the UK House of Lords to launch an investigation which is being conducted by Professor Helen Muir of Cranfield University. Muir has told the BBC that “there will be organophosphates” on the flight deck but questions whether “they there in sufficient concentrations to potentially cause harm to people.” Her report is due this spring.

Last September, EASA issued a request for information from pilots and cabin crews and the industry regarding the presence of oil fumes in the cabin and flight deck air supply to assess whether regulations are required. EASA’s position however is that bleed air contamination is “relatively rare”, and “there is no scientifically proven case of serious illness attributed to exposition to cabin air contamination by engine/APU.”

Possibly providing a different insight to the issue will be a study being carried out by Professor Clement Furlong of Washington Univ. which is expected to be completed soon. Furlong is investigating the cases of 92 pilots who have allegedly been incapacitated owing to breathing contaminated air and is trying to discover the provable causes of their impediment. In an interview with CNN last August, Furlong, when asked why the problem was not more widespread, said that “a small percentage of people appear to be highly sensitive to the most toxic chemicals.”

He explained that these individuals may be genetically disposed to a strong reaction, possessing multiple genes of metabolizing proteins in their livers, or they may temporarily have high enzyme levels which can be triggered by prescription drugs that will act on the inhaled chemicals to magnify their toxicity. This is a condition similar to the one in which some people are hypersensitive to minute amounts of chemicals including perfume and fragranced products, cleaning and personal care products, vehicle exhaust and cigarette smoke.

Furlong added: “[And] if you happen to be taking a medication that turns on the protein that converts pre-toxin to very potent toxin, you’ve got an issue.”

Overlapping the question of the potential for toxic engine and APU fumes to enter the aircraft and cause harm is the much broader issue related to the risk that passengers will spread infectious diseases among each other during flights. This gained heightened international attention during the SARS outbreak a few years ago and has remained at a low boil ever since, with a number of widely-reported incidents involving highly-infectious passengers traveling by air.

Past studies have shown that the risk of catching an illness during a flight is not from the spread of contagions through HEPA-filter equipped cabin environmental systems but from actual physical proximity to a passenger with an infectious disease in much the same that disease spread in other close environments. Nonetheless, it is an issue that will not go away.
UK-based Quest International presented BAE Systems with an air management system five years ago with a view to mitigating the risks of cross infection and global spread of disease. The system dubbed AirManager had originally been developed for use within the health industry. The first commercial application was in nursing homes, remediation of buildings and properties post fire/flood, protection of food testing laboratories from cross infection of test samples and medical applications to protect patients from airborne contaminants and manufacturing operations such as pharmaceutical, ink production and solvent utilization.

Quest’s patented AirManager CCFT [Close Coupled Field Technology] generates a ‘contained’ electrical field which has a huge destabilizing effect on all compounds and materials in the air passing through it. “Any resulting residues are then trapped by electrostatic media which have been designed to be disposed of in an environmentally friendly manner,” AirManager inventor and Quest director David Hallam says.
Testing was undertaken which was later expanded to include pyrolised oils, hydraulic fluids and de-icing fluids at BAE Systems’ suggestion that then led to the development and certification of versions of AirManager for 146/Avro RJ aircraft.

BAE Systems has signed an agreement with Quest to become a global distributor to airlines of the system for an initial period of five years and has already designed and certificated the system for installation on the 757 with a trial unit now under evaluation.

Hallam says “the main strength of the system is its ability to actively destroy a wide range of contaminants quickly.” Hallam adds that it achieves a single-pass kill rate of 99.999% of biohazards, also removing particles down to below 0.1 micron in size. However, its power usage is very low at just 3.6 watts.

The companies have conducted a rigorous scientific evaluation on AirManager and all contaminants likely to be encountered have been tested. These include volatile organic compounds such as skydrol, anti-icing fluids, NOx, organophosphates, TCP, O1 and CO; unburned hydrocarbons, biohazards such as bacteria, moulds, spores, viruses, MRSA and anthrax; and, of course, irritating odors, perspiration and galley smells. “This technology has been tested to death,” Hallam says. Five European airlines have installed AirManager in eight BAe 146/Avro RJs and the “results have been as expected,” according to BAE Systems. The next aircraft on the radar for AirManager are the 737 and A320.
Of course, it remains to be seen whether large numbers of cash-strapped airlines will be willing to make significant investments in new environmental systems, absent definitive evidence that a systemic risk exists from either toxic fumes or infectious disease. And despite a number of cases that are tragic for the individuals involved, it is difficult to conclude that this case has been made to aviation regulators.