Posts about: "Fuel Cutoff" [Posts: 330 Page: 16 of 17]¶

The head of the U.S. Federal Aviation Administration (FAA) said on Thursday the fatal crash last month of an Air India Boeing 787 jet does not appear to have been caused by a mechanical issue or inadvertent movement of the fuel control unit or switches.

"We can say with a high level of confidence is it doesn't appear to be a mechanical issue with the Boeing fuel control unit," Bryan Bedford, the FAA's administrator, told reporters on the sidelines of an air show in Wisconsin.

He said FAA employees had taken the units out, tested them and had inspectors get on aircraft and review them. "We feel very comfortable that this isn't an issue with inadvertent manipulation of fuel control," he said.

The probe into the Air India crash, which killed 241 of the 242 people on board and 19 on the ground, is focused on the fuel control switches of the Boeing 787 jetliner.

Boeing and Air India did not immediately comment.

The switches control fuel flow to aircraft engines, allowing pilots to start or shut them down on the ground, or manually intervene during in-flight engine failures.
Air India said on Tuesday it has completed precautionary inspections of the fuel control switch locking mechanism on all 787 and 737 aircraft, with no issues detected.

A preliminary report from India's Aircraft Accident Investigation Bureau earlier this month found the switches had almost simultaneously flipped from "run" to "cutoff" shortly after takeoff, causing the engines to lose power.

Reuters reported last week, citing a source, that the cockpit recording on the Air India flight from Ahmedabad to London Gatwick suggested the captain cut fuel to the engines.

Earlier this month, the FAA and Boeing privately issued notifications that the fuel switch locks on Boeing planes were safe.

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.”

According to a detailed investigation by The Federal, the Boeing jet had suffered a hard landing during its previous flight. This had led to the entire stabiliser motor trim being replaced mere hours before the Air India crash flight. Maintenance records obtained by the publication showed that both the stabiliser position transducer (sensor) and the horizontal stabiliser electric motor control unit (EMCU) were replaced on that day after the hard landing incident. And while replacement of faulty equipment would typically be a good thing, the issues went somewhat deeper here.
Three serious electrical faults in 48 hours
The investigation by The Federal noted that the stabiliser motor and related components also shared power and data paths with other critical systems on the Boeing 787 — including a fire inerter (nitrogen generation) system for fuel tank fire prevention. This is typically used to helps prevent fuel tank fires (such as the one seen during the crash) by preventing the buildup of flammable vapours. But engineers had taken the fire inerter offline two days before the crash — classifying it as a ‘high-risk active fault that needed to be fixed within 24 hours. It remained inoperative two days later as the Air India flight took off for what would be its final flight.

There was also also a separate medium risk core network issue that got flagged on June 9. Both the fire interter and the stabiliser trim motor share power and data with the digital-eletrical ‘core’ system on Boeing 787 aircraft. This network manages most onboard systems and even manages signals for the engine computers. A malfunction can therefore affect the full authority digital engine control to command thrust and fuel cutoff.

.....the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec.