Posts about: "AAIB (All)" [Posts: 166 Page: 8 of 9]¶

Contents of the flight\x92s cockpit voice recorders have been tightly held by Indian authorities and seen as key to helping fill out the sequence of events in the flight\x92s final moments.

Jennifer Homendy, chairwoman of the U.S. National Transportation Safety Board, has sought to listen to the recording herself , according to people familiar with the matter.

An NTSB spokesman said that Homendy has been fully briefed on all aspects of the Air India investigation, including the cockpit voice recording and details from the flight data recorder. Homendy said her goal in working with Indian authorities was \x93to quickly determine whether the crash presented any immediate safety concerns to the traveling public.\x94

US safety chief supports India’s Aircraft Accident Investigation Bureau in urging media to avoid ‘premature narratives’ about the 12 June disaster that killed 260 people

The head of the US National Transportation Safety Board (NTSB) has criticised recent news stories about the 12 June crash of an Air India Boeing 787-8, aligning with a statement from India’s Aircraft Accident Investigation Bureau (AAIB).

“Recent media reports on the Air India 171 crash are premature and speculative,” NTSB chair Jennifer Homendy said on 18 July. “India’s Aircraft Accident Investigation Bureau just released its preliminary report. Investigations of this magnitude take time.”

Homendy does not specify which media reports she takes issue with.

In recent days, The Wall Street Journal and Reuters, citing unnamed sources familiar with US officials’ assessment of evidence, reported that audio from the crashed jet’s cockpit voice recorder indicates the captain had moved the fuel control switches to the “CUTOFF” position. The reports said that the first officer was the pilot who asked why the switches had been moved.

A source who is also familiar with aspects of the investigation confirms that information to FlightGlobal.

Investigators have not released information to support such a scenario.



NTSB chair Jennifer Homendy warns against “speculative” media reports

The 787-8 was operating flight 171 from Ahmedabad to London Gatwick airport. It crashed shortly after taking off, killing 241 of 242 people aboard and 19 people on the ground.

The AAIB’s 11 July preliminary report said that about 3s after taking off, the two cockpit fuel control switches – each controls fuel to one of the jet’s two GE Aerospace GEnx turbofans – were switched to the “CUTOFF” position. The switch for the left-side engine moved first, with the right-side switch moving within about 1s.

The turbofans then lost thrust. One of the two pilots – the report did not specify which – asked the other why he moved the switch; the other then denied doing so.

Starting 10s after the switches were set to “CUTOFF”, both were switched back to “RUN”, causing the turbofans to begin restarting, but not in time to prevent the jet from crashing.

The 787’s flight data recorder noted the moment the actual physical switch moved to the “CUTOFF” position and then when it moved back to the “RUN” position, a source tells FlightGlobal. Those moments were plotted on a graph showing engine thrust falling off after the switches were moved to “CUTOFF”, and then returning after they were moved to “RUN”.

Because that data reflects the physical movement of the switch, a loss of fuel caused by another problem elsewhere in the 787’s electrical system is unlikely, the source says.

The Federal Aviation Administration on 11 July issued a Continued Airworthiness Notification to the International Community (CANIC) saying that the AAIB’s “investigation to date has found no urgent safety concerns related to the engines or airplane systems of the Boeing Model 787-8”.

On 17 July, the AAIB issued an “Appeal”, saying, “It has come to our attention that certain sections of the international media are repeatedly attempting to draw conclusions through selective and unverified reporting”.

“Such actions are irresponsible… We urge both the public and the media to refrain from spreading premature narratives that risk undermining the integrity of the investigative process,” it adds. “The AAIB appeals to all concerned to await publication of the final investigation report.”

Citing that document, the NTSB’s Homendy said on 18 July, “We fully support the AAIB’s public appeal… and will continue to support its ongoing investigation”.

The AAIB’s preliminary report also notes that the FAA issued a Special Airworthiness Information Bulletin in December 2018 about a “locking feature” within fuel control switches on several Boeing models, including 787s. The locking feature is a safety device that requires the switches be lifted before being transitioned. It involves raised nubs that the switch must transition over.



A fuel control switch similar to that found on Boeing 787s, showing that the switch must transition over raised bumps

That 2018 bulletin warned about potential “disengagement” of the locking feature, which could allow the switches to “be moved between the two positions without lifting”, potentially causing “inadvertent” engine shutdown.

Though the FAA recommended inspections, its bulletin concluded that issue was “not an unsafe condition that would warrant airworthiness directive”.

The FAA reiterated that position in its 11 July CANIC, saying the fuel control switch design does not pose “an unsafe condition”.

Though the AAIB’s report cited the issue, it drew no link between it and the crash

LAS VEGAS—India’s Aircraft Accident Investigation Bureau (AAIB) is now looking into the June 12 crash of an Air India Boeing 787-8 as an intentional act, says veteran safety consultant and former NTSB investigator Greg Feith . The AAIB’s preliminary report on July 12 revealed that fuel cutoff switches for the 787’s two GE Aerospace GEnx-1B engines were transitioned from “run” to “cutoff” around three seconds after takeoff from Ahmedabad Airport. Although both fuel switches were turned back on within a further 14 sec., the aircraft was too low to recover and impacted trees and buildings, killing 241 of 242 occupants on the 787 and 19 on the ground.The AAIB has criticized subsequent western media reports as “irresponsible” for indicating the fuel cutoff switches were likely deliberately moved by one of the pilots.
However, Feith says: “It has become very apparent, especially now with information I know and what's come out about the cockpit voice recorder—where the question is heard ‘why did you cut off the fuel?’—[that] somebody had to have seen that action to make that statement. You just wouldn’t have a dual-engine failure.”

Speaking at the American Institute of Aeronautics and Astronautics Aviation forum here in Las Vegas, Feith says: “Something had to prompt that type of comment. Now we get into the psychology part of it, and that's really where this investigation is going to go. “And oh, by the way, it's no longer an accident. It's investigated as a criminal event, just like EgyptAir, just like Germanwings, just like SilkAir. These are criminal events—intentional acts,” he adds, referring to three fatal crashes deemed to have been deliberately caused which occurred in 1999, 2015 and 1997 respectively.

Feith, who participated in the investigation into the SilkAir crash—where a Boeing 737-300 traveling from Jakarta to Singapore was downed—says other theories continue to persist in the face of contradictory evidence provided by the AAIB. “To this day, people are still talking about this as a dual-engine failure, despite the fact that the AAIB came out with a preliminary report which gave some initial findings. They said at this stage of the investigation, there are no recommended actions for the 787-8 or the engines. They just exonerated the airplane. They just exonerated the engines.”

“The junior investigators and the trolls are still making a big deal about engine failure, software issues, FADEC problems. They're not part of the process,” Feith continues. The AAIB “had a team of subject matter experts dissecting all of this in that 30-day period. You think they didn't look at that? It makes no logical sense,” he adds.

“The fact is that now we have people all spooled up looking at the wrong thing instead of looking at, 'is this an isolated problem or a systemic event?' It's the first major accident for a brand-new airplane [type]. This is the kind of controversy that gets stirred up and distracts us from really looking at where we need to be and what we need to be doing to enhance aviation safety,” Feith says.

Referencing the SilkAir accident, he says: “I've been down this road. I spent two years working on SilkAir in Palembang, Sumatra. I took a team of investigators over with me from Boeing and the engine manufacturer, the FAA and a variety of others, and we determined in concert with their National Transportation Safety Committee, that this was an intentional act.”

7 hours ago | Faarea Masud | Business reporter
The highest court in India has strongly criticised the country's aviation authorities for their handling of the aftermath of the Air India plane crash that killed 261 people in June.

Leaving only one survivor , the flight bound for Gatwick airport from Ahmedabad crashed shortly after taking off, killing 242 passengers on board and 19 others on the ground.

The court said it was "irresponsible" for the aviation authority to suggest, through leaks to the media, that pilot error had caused the disaster.

It called on Indian prime minister Narendra Modi for the government's response before it rules on a case filed by activists demanding an independent investigation.

The court said the way the aviation body released its preliminary report in to the Boeing Dreamliner's crash was "selective and piecemeal".

The preliminary report, publishedby India's Aircraft Accident Investigation Bureau (AAIB) in July, said fuel supply to the engines was cut off just seconds after take-off.

The report also said one of the pilots was heard asking the other "why did he cut off" in a cockpit voice recording, with another pilot responding that he did not do so.

The recording doesn't clarify who said what. At the time of take-off, the co-pilot was flying the aircraft while the captain was monitoring.

But the findings of the report have been challenged by aviation safety group Safety Matters Foundation, which is calling for an independent investigation into the crash.

In a court hearing overseeing the aviation safety group's petition, one of India's Supreme Court judges said that suggestions that the pilots deliberately shut off fuel supply were "very unfortunate and irresponsible".

The crash has left many questioning the safety of India's airspace.

The chief of the Directorate General of Civil Aviation (DGAC) has defended the safety record of the country , telling the BBC in July that "India's skies have always been safe".

That same month, the DGCA uncovered 51 safety violations at Air India in the preceding year , as part of its annual audit of the country's airlines.

The families of four passengers who died on the plane filed a lawsuit in the US against planemaker Boeing and aircraft parts maker Honeywell, accusing the companies of negligence.

The lawsuit accused the companies of doing "nothing" despite being aware of the risks of the aircraft's design.

The Emergency Locator Transmitter (ELT), a critical post-crash distress beacon, was never activated, as per the AAIB report. It was recovered intact in the wreckage, yet it was silent.A CCS/core network failure would not by itself stop the transmission from an ELT’s automatic g-switch — which is a gravity (g) switch with a sensor that detects sudden changes in acceleration (g-forces) that typically occur during a crash.

That is, unless the ELT’s antenna and wiring had melted in a fire — and one possible pointer to that is a Category A fault logged on AI 171’s Nitrogen Generation System (NGS), a safety feature Boeing added to prevent fuel tank fires in the aftermath of the Trans World Airlines Flight 800’s midair explosion due to a central fuel tank ignition in 1996.

The NGS works by continuously flooding the tail fuel tank’s ullage (the empty space above the fuel) with nitrogen-rich air, displacing oxygen and thereby preventing the build-up of flammable vapours.

If the NGS were not functioning, the oxygen levels around the aft-fuel tank bay may have been dangerously high. In that scenario, even a small spark—possibly from an electric arc or surge—could ignite a localised fuel-air vapour fire. That would have burnt the wiring and antenna of the ELT and wiring, connectors, and housing of tail-section black box or the aft Enhanced Airborne Flight Recorder (EAFR). And this scenario would be in line with the AAIB report, which shows the tail section was more structurally intact compared to the nose.