The head of the US National Transportation Safety Board (NTSB) collaborated with a statement from the Indian Aircraft Accident Investigation Bureau (AAIB) to criticize a recent news article about the June 12 crash crash of the Air India Boeing 787-8.
“Recent media coverage of the Air India 171 crash is premature and speculative,” NTSB Chairman Jennifer Homendy said on July 18th. “The Indian Aircraft Accident Investigation Bureau has released a preliminary report. An investigation of this scale will take time.”
Homedy does not specify which media is having problems.
Recently, the Wall Street Journal and Reuters reported that audio from the cockpit audio recorder of the crashed jet indicates that the captain moved the fuel control switch to the “cutoff” position, citing an unknown source familiar with the assessment of the evidence of US officials. According to the report, the assistant officer was a pilot and asked why the switch was moved.
Sources who are also familiar with aspects of the research are reviewing information on FlightGlobal.
Investigators have not made any public information to support such scenarios.
787-8 operated flights 171 from Ahmedabad to London Gatwick Airport. It crashed shortly after takeoff, 240 of the 241 people boarded, and 19 were killed on the ground.
AAIB's July 11 preliminary report states that about three seconds after takeoff, two cockpit fuel control switches, each controlling the fuel to one of the two GE Aerospace Genx Turbofans in the jet, were switched to the “cutoff” position. The engine switch on the left moved first, and the switch on the right moved within about a second.
The turbofan then lost its thrust. One of the two pilots – the report asked the others why he moved the switch, although no pilot had been specified. Others denied doing so.
It started 10 seconds after the switch was set to “cutoff”, both returned to “run”, and the turbo fan began rebooting, but not in time to prevent the jet from crashing.
The 787 flight data recorder noticed the moment the actual physical switch moved to the “cutoff” position, and when it returned to the “run” position, the source tells FlightGlobal. These moments were plotted on a graph showing engine thrust falling after the switch moved to “cutoff”, then back after moving to “run”, then the engine thrust falling.
The data reflects the physical movement of the switch, so there is unlikely to be any fuel loss caused by another problem elsewhere in the 787's electrical system, sources say.
On July 11, the Federal Aviation Administration issued a continuous airworthiness notice to the International Community (CANIC), which stated that AAIB's “previous investigations have no emergency safety concerns related to the engine or airplane system of the Boeing Model 787-8.”
On July 17, AAIB issued an “appeal” that “he noted that certain sections of international media are repeatedly attempting to draw conclusions through selective and unverified reports.”
“Such action is irresponsible. We urge both the public and the media to refrain from spreading premature narratives that risk eroding the integrity of the investigation process,” it adds. “AAIB asks all involved to wait for the final investigation report to be released.”
Citing the document, NTSB's Homedy said on July 18th that it “will fully support the public appeal of AAIB and continue to support ongoing research.”
AAIB's preliminary report also points out that in December 2018 the FAA issued a special aircraft information bulletin about the “lock function” in fuel control switches on several Boeing models, including the 787. The lock function is a safety device that requires you to lift the switch before transitioning. Includes raised nubs that the switch needs to migrate.
Breaking news for 2018 warned of a potential “withdrawal” of locking features. This allows the switch to be “moved between two positions without lifting”, which can cause “inadvertent” engine shutdown.
The FAA recommended inspections, but the breaking news concluded that the issue was “not a dangerous condition that guarantees Air Force directives.”
The FAA repeated its position in the July 11 can, saying that the fuel-controlled switch design would not result in a “hazardous condition.”
The AAIB report cited this issue, but there was no link between the crash.
