Early attempts to eliminate cabin air contamination are under way in commercial air transport, despite industry reluctance to admit the risks associated with the problem.
That emerged as a consensus at the Global Cabin Air Quality Executive's annual information exchange held in London on 22-24 April.
GCAQE co-chairman Tristan Loraine argues for the need to keep up pressure on the industry to stop harmful engine oil fumes getting into airliner cockpits and cabins. Fumes can enter via the engine bleed air used for air conditioning and pressurisation.
While the fact that fume events occur is accepted within the industry, there is dispute over the contention that organophosphates in the oil have neurotoxic effects on crew and passengers. The GCAQE says that fumes' harmfulness is evidenced by hundreds of officially reported events in which the pilots' and cabin crew's mental and physical capabilities were severely compromised. However, the general industry position is that the events are rare and survivable.
Loraine says there have been attempts to solve the problem by improving engine oil seal maintenance, and by reducing the toxicity of organophosphate anti-wear components in the oil. The motivation to improve, he adds, is heightened by increased reporting of the issue in the media, advancing evidence from medical research laboratories on neurological biomarkers for "aerotoxic syndrome" in passengers and crew, and also by the cost of increasing in-flight diversions forced by fume or smoke events.
Meanwhile, the head of French aviation lubricant manufacturer Nyco, Eric Piveteau, says his hopes of commercially launching a new, less-toxic aero-engine oil have been put on hold because the results of research were not as promising as he had expected. Piveteau's aim is to create an oil that has the same high performance as existing lubricants using less toxic ingredients. The barrier, he says, is that the high-performance laboratories he employs to create and test new molecular structures are working at full stretch. The test ingredients he seeks will have "a molecular structure that is not available off the shelf".
Existing aviation lubricant producers are reducing the percentage of allegedly harmful organophosphates in their oils as low as they can without significantly affecting its anti-wear performance, he adds.
Robert Flitney, a specialist on the technology of industrial seals, warns that there is no such thing as a seal that does not leak, and that as soon as a seal becomes degraded, the leakage rate increases in proportion to the cube of the widening space created by the wear process.