787

Dodging the verdict

David Learmount , , , , , , , , , , , , , , ,

Hundreds of airline pilots and cabin crew who have had their health permanently damaged by neurotoxins in aircraft cabin air joined a three-day multinational conference in late June to hear about the latest technical and legal solutions to the problems they face.

Hosted in London, England, the online Aircraft Cabin Air Conference drew in speakers and delegates from all time zones. Developments revealed at the event include a new blood test that scientifically confirms exposure to the specific organophosphates in jet engine oils that cause the harm by leaking into the engine bleed air that ventilates the cabin.

Also revealed was a new regulation to aid exposed crews and passengers: the US Cabin Air Safety Act. The purpose of the Act is to “improve the safety of the air supply on aircraft”, and it requires that all flight crew, maintenance technicians and airport first responders are to be given training – at least annually – on how to respond to “incidents onboard involving smoke or fumes”.

Meanwhile, in recent years, many medically harmed crew-members have – individually – been financially compensated by their employers for consequential health damage, but the air transport industry as a whole is still able to turn a blind eye to this fully understood phenomenon.

The reason the industry – the airlines themselves and the aircraft and engine manufacturers – appear to get away with tolerating such a recurring phenomenon is simple. Whenever they are challenged in the courts over cases of human health damage caused by contaminated cabin air, the companies settle out of court with the plaintiffs, who desperately need the compensation money because their career – as well as their health – is in ruins. So, the court does not get as far as delivering an actual verdict on the harm, the cause, or the blame.

Meanwhile a US law company, Littlepage Booth and Athea, has assembled a formidable body of technical and medical evidence on the effects of contaminated cabin air while representing harmed individual clients. The specific evidence these lawyers have gathered implicates only Boeing. That is purely because – they say – Airbus is a more complex legal task to take on in the USA.

Ironically, the only modern airliner in service today that does not use engine bleed air for air conditioning and pressurization is Boeing’s own 787, the most recent entirely new aircraft off its production line. The company explains it has abandoned the bleed air system in the 787 for fuel consumption reasons. But the 787 – also uniquely – does not use bleed air from its auxiliary power unit (APU) for cabin air ventilation, although there is no fuel consumption advantage in so doing. Law company partner Zoe Littlepage confirmed that the body of evidence against the manufacturer may be extensive, but until a trial has gone all the way through the courts and a verdict is reached, the status quo will remain.

The organophosphate contamination of cabin air is caused when aero-engine oil and/or hydraulic fluid leaks into the cabin air conditioning system, the air supply for which is drawn from the jet engine compressors. This contamination is not supposed to happen, but from time to time “fume events” occur when an engine bearing fails and the vaporized synthetic lubricants are “pyrolized” – partially burned – by the hot compressed air – and mixed into the cabin air that the pilots, cabin crew and passengers breathe. There is no filtration of this “bleed air” supply, and no detection systems to warn those on board when contamination is present. There is, however, usually an unpleasant smell, and sometimes visible smoke.

Pilots and cabin crew are more at risk than passengers, because even undamaged oil seals are not perfect, and there is constant leakage of the heated oil vapors in the bleed air into the cabin air at a very low rate. In some individual crew, the inherent toxins can slowly build up in their metabolism through repeated exposure, and because “aerotoxic syndrome” is still not legally recognized by the authorities, non-specialist medical doctors are unlikely to make a correct diagnosis of the resulting symptoms.

The authorities claim these very low rates of leaked fumes are acceptable, but that cannot be so because there is no designated rate or dose of these organophosphate-based neurotoxins that is defined as acceptable.

Fume events, on the other hand, are potentially dangerous to all. Passengers, however, are not generally warned of the risks when an event has occurred, and frequently the occurrence is not reported. And if – later – passengers suffer symptoms like persistent excessive tiredness, dizziness or “brain fog”, they may not connect their problems to their flight, and their doctor is unlikely to diagnose the problem accurately.

And so it goes on.

The Max crux

David Learmount , , , , , , , ,

Boeing, the FAA, and national aviation authorities (NAAs) from several other countries, met in Dallas on 23 May to consider the future of the 737 Max series of aircraft.

It is impossible to overstate how important this meeting is. The way civil aircraft manufacturing does business, not just in America, but all over the world, is under scrutiny.

Detail gradually emerging from Boeing and the FAA following the two 737 Max fatal crashes has upset such basic assumptions about the way modern aviation works that industry veterans – whose initial reaction was that this was just a case of finding a fix and getting the Max airborne again – are , only now, fully realising it’s not.

Like the Looney Tunes cartoon characters who ran over a cliff they didn’t know was there, we didn’t begin to fall until we looked down.

Let’s examine the proposal that all airliners nowadays are massively computerized, so adding some digital controls to the good old 737 to make it a Max is just bringing the 737 marque up to date.

After all, digital controls work on other types like Airbuses and Boeing’s own 777 and 787, and they are safe, so why not on the 737?

Back to basics.

All modern commercial airliners are supposed to be designed, in the first place, so they fly easily and intuitively, and have a natural aerodynamic stability within their flight envelope. That should hold true with or without computer control.

Designing an aircraft to be fly-by-wire, rather than conventionally controlled, can provide additional safeguards, but the airframe itself should still fly naturally.

Applying a digital solution to an airframe-related flight characteristic that is undesirable is a different matter entirely; but that is what Boeing chose to do when it installed the Manoeuvring Characteristics Augmentation System (MCAS) in the new Max.

The fact – revealed by the fatal accidents – that the MCAS could be triggered when it was not needed, and what consequences might follow its triggering, appears not to have been examined in any depth by Boeing or the FAA.

The fundamental questions for the FAA – and the foreign NAAs- are these: is the Max, as a simple airframe without digital corrections, sufficiently stable within its flight envelope to satisfy the regulators it is worthy of certification?

If not, is a digital fix sufficient to cover the undesirable flight characteristics lurking in a corner of its flight envelope? How reliable does the fix have to be to win approval?…and how can its reliability be proven?

For three decades the aviation world has agreed to operate a regime whereby the NAAs in countries where aircraft are manufactured all use the same standards when they certificate a new aircraft. So when the FAA certificated the 737 Max, the rest of the world accepted the FAA’s judgement and did not insist – as in the bad old days of the 1970s and before – on re-certificating it country by country.

What if, in this case, the FAA re-certificates the MCAS-modified Max, but foreign NAAs do not? The European Cockpit Association today has called on the European Union Aviation Safety Agency to scrutinize any FAA approvals, and EASA has pledged to do so. Is this “back to the bad old days”?

At the end of the Dallas meeting Boeing had this to say: “We appreciate the FAA’s leadership…in bringing global regulators together to share information and discuss the safe return to service of the 737 MAX….Once we have addressed the information requests from the FAA, we will be ready to schedule a certification test flight and submit final certification documentation.”

Industry speculation as to when the FAA will be ready to approve return to service varies massively, from a week to many months. These seers also seem to be preparing themselves for disagreement between the FAA and foreign NAAs.

This is the point at which you dare not look down.