NTSB

DC-10 crash nightmare runs again

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

On 25 May 1979 the worst airline crash in America’s history occurred during take-off at Chicago O’Hare airport, killing all 271 people on board. Now, on 4 November at Louisville, Kentucky, an unnervingly similar disaster has occurred, also immediately after take-off.

But because the Louisville crash involved a freighter, far fewer people died, and for that reason the event has not received the same international wall-to-wall coverage in the media as the 1979 catastrophe.

Some 46 years may have passed since the crash of American Airlines Flight 191 at Chicago O’Hare, but it remains the worst aviation accident ever to take place on US soil. It also happens to be the first major accident upon which I had to report as a rookie aviation journalist with Flight International magazine, so my memories of it remain vivid.

The similarities between the two accidents were these: both aircraft were McDonnell Douglas (MDC) DC-10 trijet variants; both, late in the take-off run when the aircraft were already committed to take off, suffered complete detachment from the left wing of the No 1 engine.

Flight 191 involved an MDC DC-10-10 passenger aircraft, whereas the Louisville accident involved the most recent variant of the DC-10 series, known as the MD-11, and it was a freighter version operated by UPS with only three crew on board.

The UPS MD-11F engines were Pratt & Whitney PW4460s and Flight 191’s power units were General Electric CF6-6Ds, but the common factor in both cases was that they ripped themselves off their wing mountings, damaging the wings disastrously in the process and making the aircraft completely unflyable. Nobody on board either aeroplane had a chance of survival. At O’Hare two people on the ground were killed, and at Louisville the death toll of third parties is estimated at nine, with at least 11 injured.

The National Transportation Safety Board (NTSB) investigation of the 1979 accident found that improper maintenance practices by American Airlines when they re-mounted the left engine on the wing following overhaul had resulted in damage to the wing mountings where the engine pylon attached to the wing itself. The report says that, when the engine detached, it pivoted upward and passed over the top of the wing as it departed, the separation causing physical damage to the wing leading edge and to hydraulic systems, resulting in the retraction of the left wing leading edge slats which dramatically reduced the lift that wing was able to produce at low speed. The wing dropped uncontrollably, and the aircraft hit the ground inverted.

At this stage all we know about the UPS accident is that the NTSB have recovered the flight data and cockpit voice recorders, and that witness from the ground and wreckage disposion at the site makes it certain that the left engine separated, causing damage to the wing, which then dropped and hit the roof of an industrial unit beyond the runway end. So far there is no evidence to suggest that the separation took place in exactly the same manner that it occurred on Flight 191, nor for the same reason. Additional video information showing the No 2 (tail) engine emitting flame suggests debris from the No 1 engine separation damaged it, making it impossible to maintain level flight.

Additions to detail since the NTSB released a preliminary factual report: the Lousville departure was Flight 2976 for Honolulu, and it took off from runway 17R reaching a maximum height of 100ft (the original statement said 475ft, but the NTSB has now reviewed the ADS-B data from which that was derived) and airspeed of 183Kt. Also, most of the No 1 engine’s pylon was still attached to the engine when the NTSB found it, but probably received additional damage when hitting the ground after detaching from the wing. The separation process began with a fatigue failure of the left engine pylon’s aft attachment lugs, so the engine and pylon detached as a unit from the wing underside. The engine twisted upward and passed over the top of the aircraft, gyroscopic precession causing it to fall to the right of the aircraft’s path, and debris entered the tail engine causing a reduction in power, making descent inevitable.

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.

Washington DC airspace will stay risky

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

Activity in Washington DC’s urban airspace is now being constrained – just a little – by the Federal Aviation Administration following its discovery that the risk of collisions at or near airports across the whole USA is higher than the Agency had appreciated.

This fact emerged during the inquiry by the National Transportation Safety Board (NTSB) and FAA into the 29 January fatal mid-air collision between an army helicopter and regional jet airliner over the Potomac River near Washington Reagan airport.

This decision to reduce traffic, however, is likely to be challenged, and probably quite soon.

The appetite for instantly accessible air transport among DC denizens is insatiable because – they would tell you – of the febrile environment in which many of them conduct their political, lobbying, military or security business in the District. There is always high demand for flights to and from DC’s compact downtown airport close to the heart of the city, and it operates near capacity all the time. Reagan airport is right next to the west bank of the Potomac River, and the other side of the river directly opposite the airfield there is a confluence of urban helicopter routes (see chart below, helicopter routes marked in blue). In addition to that complexity, less than a mile to Reagan’s north west is the Pentagon, with its own heliport.

On the night of the collision the PSA Airlines Bombardier CRJ was approaching Reagan from the south, tracking northward above the Potomac River, intent upon intercepting the instrument landing system (ILS) for runway 01 to land. Meanwhile the army Black Hawk was to the north of Reagan, tracking south along helicopter Route 1 to join Route 4.

Reagan tower asked the CRJ crew if they could accept a late runway change to land on 33, and because the crew could see the lights of both runways they accepted the change, broke off from the runway 01 ILS while still at about 1,700ft, and made a slight right turn to head north to intercept runway 33 ILS. Approaching ILS intercept, the CRJ turned onto final approach at about 500ft. As the CRJ descended through 300ft toward the runway the two aircraft collided.

The circumstances of the collision are not surprising given that these operations were carried out under night visual flight rules (VFR), and the visibility at the time was such that visual identification and separation was practical, if not actually wise. Asked by Reagan tower if they had the CRJ in sight, the Black Hawk crew said they did, although the fact of the collision makes it clear that they had misidentified the regional jet. The lights of the city and airport crowd around on all sides, making misidentification easy.

It has since transpired that the army helicopter was not operating its ADS-B-Out to enable identification by ATC, which it was supposed to do. Right now there is a behind-closed-doors argument going on between the army and the FAA about the military use of ADS-B-Out. The army doesn’t like its aircraft to be trackable, and the FAA insists they must be identifiable in environments like DC airspace. There was, however, no special security classification that demanded stealth for this particular helicopter flight, which was carrying out crew training.

Chair of the NTSB Jennifer Homendy remarked upon the failure of the FAA to respond to the fact that the exact point at which the two aircraft collided had long been identified as a “high risk location”. This failure, she said, was “more than an oversight.” When it was published in early March, the NTSB’s preliminary report on the accident revealed that, between October 2021 and December 2024, there had been more than 15,000 “close proximity events” between helicopters and commercial aircraft near Reagan.

It may be a useful exercise to gather statistics like that to back an argument, but anyone who operates the skies near Reagan knows how busy it has always been, and knows that such a level of traffic density involves considerable risk, especially at night or in poor visibility. The operational requirements for a helicopter heading south on Route 4 are that, when passing Reagan, it is supposed to be at 200ft or lower, so that any aircraft on approach to runway 33 should pass over the helicopter at a height between 300ft and 400ft. The margins for error are tiny, both for vertical separation between the two aircraft, and for obstacle clearance between the low-flying helicopter and ground obstructions, especially risky at night.

The FAA has now decided to close Route 4 whenever runway 33 is in operation. But what if, like the day of the accident, the tower decides at short notice to change a landing from runway 01 to 33? Can sufficient notice be given to helicopter crews using Route 4? The agency plans to allow some limited helicopter traffic on Route 4, but only for “urgent missions, such as lifesaving medical, priority law enforcement or presidential transport”. Unfortunately such flights over this city are common, and there is a question as to who should authorize them. Meanwhile ATC will be expected to prohibit fixed-wing aircraft from simultaneously using Reagan airport’s secondary runways – 15/33 and 04/22. That combination of responsibilities is quite an ask for controllers as busy as those at Reagan.

The FAA’s administrator Chris Rocheleau, at a Congressional Hearing on 27 March, obviously bidding for the Understatement of the Year Oscar, said: “Clearly, something was missed.” The NTSB’s Homendy pointed out that the DC airspace incident data is there to be easily gathered, in the form of voluntary safety reports of near-accidents of all kinds, but admits there is a lot of it. Rocheleau says the Agency is now looking into using artificial intelligence to sort through “tens of millions” of such reports to identify – and flag up – specific risks and trends.

Urban aviation activity like that in Washington DC’s airspace would not be permitted in similar European airspace. Instrument flight rules (IFR) would apply, even if visual separation was used as a backup in VMC. That is not to say Europe is right and America is wrong. Each State has a right to decide what level of risk it finds acceptable, and to determine ways of ensuring that its agreed standards are met, in the knowledge that the authorities will take the rap if they get it wrong.

That is the question Washington DC must answer: how much risk do its denizens want to take, and should they be allowed to take risks at that level? In the 29 January collision all the people on both aircraft died, but the machinery fell harmlessly into the river. In a future collision, that might not be so.

In DC, my money is on a win for the risk-takers who are not prepared to slow down.

US pilot shortage set to ‘isolate small communities’

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

The US airline pilot shortage is not exactly breaking news, it’s a problem that has been developing as a result of the post-pandemic resurgence in air travel, but it continues to worsen.

The shortage hits the regional and small commuter airlines hardest, because the national carriers poach their captains and copilots, especially those with experience. They have always done this, but the situation for the regionals is particularly dire right now.

In a statement in its just-published end-of-year report, the US Regional Airlines Association’s CEO Faye Malarkey Black, has warned: “If policymakers fail to do their job, and do not give the pilot shortage the urgent attention it warrants, small community air service will be a thing of the past, and air travel will soon be a privilege reserved for those residing in our urban centres.” 

The report reveals that about 500 regional aircraft types are grounded across the country for lack of pilots to fly them. In November the RAA had estimated that the US airline industry had a shortage of about 8,000 pilots overall. Some of the larger regionals like Piedmont and PSA have been offering tempting joining bonuses, but these and the need to boost pay to retain pilots is becoming another factor in making marginal regional operations un-viable.

Voicing a familiar theme, Malarkey Black highlights the sky-high cost of training for professional pilots, and calls for legislation focused on “equitable access to aviation careers”, adding that the government “should be moving heaven and earth to make it easier for aspiring pilots from all backgrounds to access affordable, high-quality training”. Black urges: “We need to bring forward legislation to allow the next generation of pilots and mechanics to obtain student loans and grants.”

America is not the only part of the world where post-pandemic pilot shortages exist, but it does have a unique rule that makes it impossible for licensed pilots to enter the airline industry immediately following training, even if the training was airline-specific. This rule makes the pilot shortage – particularly for the commuter carriers where many rookie copilots would normally begin their professional careers – far worse.

This rule, requiring that pilots must have 1,500h in their log book before they can fly for commercial airlines, was the result of a kneejerk political reaction to a fatal commuter crash in February 2009 near Buffalo, in upstate New York. A Colgan Air Bombardier Dash 8 stalled during the night-time descent toward Buffalo airport, the crew lost control, and all 49 people on board were killed.

The National Transportation Safety Board’s main verdict was that the crew had not monitored the airspeed and had failed to lower the nose to un-stall the wings when the stickshaker activated. There were many other circumstances that were arguably contributory factors, including crew fatigue and the matter of crew training performance records, but federal politicians saw fit to attribute the whole thing to a lack of flying hours, so they mandated the 1,500h rule.

Thus, in America, a pilot with a full commercial license at the end of training – which normally means he or she has about 400 hours in their log book – cannot fly as copilot for an airline even if the carrier thinks they are good enough. They have to become flying instructors, obtain any kind of general aviation job, or fly single-pilot Cessna Caravan freighters for a small package delivery company until they have notched up 1,500h.

Many in the industry believe the 1,500h rule was never appropriate, but even more so now when modern pilot training programs take advantage of today’s much smarter flight simulation training devices to render a newly-trained pilot ready for the right hand seat in a commercial airliner. Change, however, does not look likely.

That American Boeing 757 crash at Cali in 1995: should the investigation be reopened?

David Learmount Uncategorized , , , , , ,

American Flight 965, a Boeing 757 descending at night toward its destination at Cali, Colombia, collided with an Andean mountain ridge, killing 159 crew and passengers. Miraculously, four passengers did not die.

The accident report that emerged from the investigation laid all blame at the feet of the pilots, softening the blow by citing some flight management system navigational anomalies as contributory factors.

Recently an independent re-examination of the data by a team of aviation and accident investigation experts has concluded that simply writing off the crash as “pilot error” was a bad decision. The pilots were among American’s best, yet the crew exchanges on the cockpit voice recorder, according to their peers, demonstrated a degree of confusion that was out of character.

Initially the Colombian/American investigation team believed alcohol in the pilots’ blood might have been a factor, but later forensic testing confirmed the alcohol was a product of tissue degeneration. Having ruled out alcohol as a cause of the pilots’ uncharacteristic confusion, the investigators failed to ask whether there might have been an alternative explanation for it, confining the event to history as simple pilot error.

A new feature-length documentary film about the American Airlines Flight 965 opens in the USA this week, examining the official accident report produced at the time by the Colombian authorities with the aid of the US National Transportation Safety Board. It raises questions that should have been asked at the time, but were not.

If this new investigation reveals the truth for the first time, it will shake public confidence in the commercial air transport industry.