Boeing 787

AI 171: the system is beginning to leak under pressure

David Learmount Uncategorized , , , , , , , , , , , , , , , , , , ,

Air India flight 171 crashed immediately after take-off from Ahmedabad on 12 June, and today, two weeks later, with no news about causes, the system is beginning to leak.

This is what happens naturally when information which people know is available to the authorities is withheld from the media and the public.

It’s easy for authorities like the Indian Directorate General of Civil Aviation to believe they can justify withholding information on the grounds that it’s very complicated, and they intend to release it quite soon anyway. Unfortunately for the DGCA, today’s media environment does not have that kind of patience any longer, especially in a case like this.

This fatal accident, a first for the Boeing 787 of any marque, killed 241 people on board and many on the ground. Whatever the cause was, it was highly unusual – maybe unique. For that reason, the industry and its regulators are desperate to know if there might be an unknown latent failure in the 787, so they can stop it happening again.

This pressure is what causes the system to leak. The Air India 171 flight data recorder has been downloaded by the National Transportation Safety Board for the DGCA at the Air Accident Investigation Bureau in Delhi, so some outstanding data will already be clear, even if not fully analysed yet.

Meanwhile the NTSB is sworn to secrecy according to the International Civil Aviation Organisation protocol which states that the nation in which the accident occured is responsible for the investigation. So in this case, the NTSB provides all its data to the DGCA, but as an agency of the nation in which the accident aircraft was designed, built and certificated, the NTSB has a particular responsibility to ensure that all operators of Boeing 787s throughout the world – there are about 1,000 of the type flying today – learn as fast as possible what, if anything, they should do.

That NTSB responsibility is a heavy one, but at the same time they want, if possible, to stick to the protocols to ensure the investigation proceeds calmly.

The NTSB obviously has to tell Boeing any details that are emerging. Then Boeing has an urgent duty to provide advice to 787 operators, particularly if any system failure detected might possibly repeat. This information will be received at Boeing by many engineers and technicians who must act rapidly to frame a plan for inspections and corrective action, then communicate with the operators, where an even larger group of airline technicians must carry out the Boeing advisories, or any directives that the Federal Aviation Administration may see fit to issue.

The pressure on the DGCA is of a different kind, and arguably less urgent. It is, after all, a regulator, a bureaucracy, with the responsibility to oversee the investigation and ensure it is conducted properly and according to law. It does, however, face the reality that a lot of highly relevant information is being shared right now by hundreds of experts all over the world, and the media knows it. So if the DGCA delays release of established facts, it will face increasing censure, especially if it delays release beyond one calendar month from the date of the accident.

A month is now firmly established as the time it should take for an air accident investigator to establish the basic facts of the case, and release a “preliminary factual report”. The final report can take more than a year.

Meanwhile, what of all those FDR facts whizzing around the world between experts at the manufacturer, the investigator, the world’s civil aviation authorities, and all the airlines that operate 787s? Well, they leak, of course, because they are important and everyone knows it. But most of the time the precise source of emerging information isn’t obvious, because individuals discussing them do not want to be recognised, so responsible journalists have to be careful what we do with what we hear.

What happens, however, is that it gradually becomes clear, among the plethora of opinions and guesswork always out there, which facts are beginning to establish themselves.

Some are simple, almost obvious. For example, the one emergency radio call made by the AI 171 crew said they had lost power, and an observation of the flight path almost immediately after unstick corroborates that puzzling fact.

But double engine failure immediately after take-off is almost unheard of, so what caused it? That is less obvious.

The DGCA has issued a list of checks it required Indian 787 operators to carry out. Unfortunately it lists checks that – mostly – are routine and would be carried out anyway.

The exception to that is the requirement to test the Electronic Engine Control System. These are computers called Full-Authority Digital Engine Controls (FADEC) that monitor the engines’ performance and react to demands by the pilots via the power levers or the flight control panel (autopilot input). These are vital, but have been established since the 1980s as highly dependable devices, and more reliable by far than the old mechanical connections.

So if both FADECs failed that would be extraordinary. In fact it makes more sense that something else failed or malfunctioned and disabled both FADECs. There is a lot of credible information gathering that backs this up, but since its precise source is not certain, I will not run it here.

Suffice to say we will soon learn what the problem was, because the DGCA knows it would look very bad to sit on it beyond 12 July 2025.

Enhanced checks for GEnx-powered Indian 787s

David Learmount Uncategorized , , , , ,

India’s Directorate General of Civil Aviation (DGCA) has issued orders for “enhanced checks” to be carried out on Boeing 787s powered by GEnx turbofans registered in the country.

Those looking for clues as to the causes the authorities believe might be behind the disastrous Air India 787 crash at Ahmedabad on 12 June are likely to be disappointed, because the checks cover a broad spectrum of systems and components, many of which would be checked before all flights as a matter of routine.

But here is the instruction anyway.

Darwinian thoughts on airliner species in a pandemic

David Learmount Uncategorized , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

The Covid-19 pandemic’s dramatic effect on air travel has accelerated aircraft retirements, particularly older long-haul types. This, of course, includes the undisputed Queen of the Skies, the Boeing 747, the withdrawal of which has been the cause of many misty-eyed moments among aviation romantics.

British Airways’ last 747-400, in retro BOAC livery, on its way to retirement

The “other jumbo”, the Airbus A380 was already suffering a crisis of its own before Covid’s arrival, and the pandemic motivated the manufacturer to put the trickling production line out of its misery.

The A380 – technically an excellent, if over-engineered aircraft – was the victim of a miscalculation by Airbus way back in the late 1980s-early 1990s about the shape of future global air transport. The A380 was to replace the 747, but the belief that a replacement would be needed at all was based on an assumption that the industry would continue to develop much as it had in the previous three decades.

Emirates, by far the A380’s biggest user, will certainly be able to continue flying many of them

That didn’t look like a bad decision at the time, but Boeing’s predictions turned out to be far more accurate. The US manufacturer foresaw the diminution of the importance of hub-and-spoke networks feeding the world’s major airports where they sit astride the globe’s air travel arteries – the traditional trunk routes. The A380 was ideal for serving these.

But the American manufacturer’s crystal ball showed smaller widebody twins taking over from thirsty quads, and carrying passengers who wanted it straight past the massive hubs directly to the secondary cities. The 767 was already showing the way in the 1990s, with American carriers on transatlantic routes, but the 777 and 787 extended the possibilities. Darwin had smiled on Boeing.

Although Airbus was also ready for many of these long-haul twin opportunities with its flexible A330 twin series (and now the A350), in the mid-1990s the four-engine A340 had initially become much more popular than Airbus had predicted. Europe, culturally less of a risk-taker than the USA, was not yet ready to fly twins over extended oceanic routes, or over endless Arctic and Siberian wildernesses. In a quad, an engine failure raises the crew’s blood pressure a bit, but they can elect to continue to destination. In a twin, it means an instant diversion.

Meanwhile, across the Atlantic, in July 1995, Boeing and the Federal Aviation Administration were ready to gamble on bringing a brand-new big twin, the 777, into service with pre-cleared permission to fly over oceanic or wilderness regions where the nearest diversion airport could be up to three hours away at single-engine flying speed. That extension from the previous 2h meant there were hardly any routes a twin couldn’t fly. Boeing and its FAA partner went for it; and what’s more they got away with it. A single early-days disaster would have put paid to that policy, but it didn’t happen, and now everyone takes 180min ETOPS (extended twin engine operations) for granted. Darwin had smiled on Boeing once more.

Today, in the pandemic, the Airbus A340 is suffering a fate similar to the 747’s, but there will be fewer tears simply because it could not have achieved the iconic status the 747 had won through its status as the world’s first jumbo jet, its sheer longevity, and its unique shape.

Among today’s widebodies, Darwin will continue to smile on the newer big twins, and the few remaining tri-jets and the older big twins will be parked or converted to freighters before their time would normally be up. Meanwhile, the marketplace that the new big twins have had to themselves for some time is to be invaded by what may turn out to be a particularly timely product: Airbus’ single-aisle venture into long-haul, the A321XLR.

Another anomaly brought by the pandemic is that air cargo has been the saviour of many airlines during the pandemic, because unlike passenger traffic, cargo has hardly been affected. For example, Taiwan’s China Airlines has just announced an operating profit for 2020 on the back of cargo, and recently took delivery of a new 777F.

Short-haul – and thus the single-aisle fleet – has not been hit as hard as long-haul simply because domestic air travel is free of the border restrictions that nation states impose on travellers when they fear the spread of infection from abroad.  But as in their long-haul fleets, airlines are still disposing of the earlier versions of their 737s, A320s and regional aircraft.

Exceptionally on a global scale, the US domestic carriers are forecasting break-even levels of passenger business by June, with strong demand from the leisure travel market, although there is slightly less confidence in a business travel rebound. Domestic carriers elsewhere, in less geographically large countries – particularly those with mature high speed rail networks – will take longer to recover than the likes of American, Delta, United and Southwest, and may not have had the government injection of survival cash the US airlines have had – plus the boost from the fact that the USA has successfully accelerated its Covid vaccination programme. Is that Darwin smiling on America again, or just on big, prosperous nations? He may well be smiling on China too.

No-one can be sure of the post-Covid shape of the world’s commercial air transport industry. Truisms, abound, like the contention that the strongest carriers will survive, and that the pandemic’s result will be further consolidation and fewer airlines. One of the unknowns is whether people’s travelling priorities will have changed, especially in the light of growing concern about climate change. Will long-haul, in particular, be a victim of such a concern?

But at present, whenever there is a hint that lockdown may be eased, people are rushing to book holiday travel. Air travel will indeed survive, the question is: what will it look like?