As the hour struck midnight on Friday, July 12 -just in time to meet the globally prescribed deadline-the Aircraft Accident Investigation Bureau released a loosely worded and unsigned preliminary report examining the AI-171 crash of June 12 that killed 260 people, including 12 crew members.
Social media and the internet exploded with further speculation, with many arguing the much-awaited report invited more questions than answers. Now, with the Wall Street Journal reporting that the captain cut off fuel supply to the switches, citing anonymous sources familiar with the evidence, there are even more questions.
Clearing Some Air
Aviation industry executives pointed out that the preliminary report did clear the air to an extent, ruling out several initial theories. The possibility of a bird strike leading to dual-engine malfunction was eliminated. The report also rules out pilot fatigue, arguing both pilots had adequate rest. Wind shear, weather and aircraft weight problems also appear ruled out.
Questions were previously raised about aircraft flaps remaining retracted and incorrectly set for takeoff, but experts say this might have been a consequence of dual engine failure. The aircraft’s landing gear also remained deployed throughout the short flight, while on a 787, wheels are normally withdrawn immediately after takeoff.
The report states that fuel loss led to engine malfunctions, caused by fuel control levers “transitioning” from run to cutoff position within one second of each other. This is clearly the main cause since both engines lost power once fuel supply was cut. The report is silent on how this happened, although it paraphrases an interaction between pilots to suggest manual error may have been responsible. The WSJ report now identifies the captain as the person who allegedly cut off fuel. India’s aviation regulator is yet to respond.
When Each Second Counts
Even after the preliminary report became public, a theory gained ground that the crash might have been deliberate pilot suicide, of which there have been more cases than most readers would be aware. But senior commanders and experts point to important lacunae with this theory.
The report states that at 08:08:42, both engine fuel cutoff switches “transitioned”-a highly ambiguous word-from run to cutoff position one after another with a one-second gap. “This rules out human action as it is physically almost impossible to move switches for both engines within one second since these are safeguarded and require two actions to move even one switch, let alone two,” explains a senior B787 commander.
Moreover, if a commander is set on suicide, he is unlikely to hand over controls at takeoff to the copilot. “Nothing stops the commander from speeding on the runway and crashing into the airport wall if he chooses. Why risk manipulating fuel switches? What if the second engine had recovered in time?” argued another commander, saying this theory fails to hold water.
While IndiGo started regular psychological assessments for pilots in 2015, Air India doesn’t have such a system, but airline executives argue that for a captain with a death wish, there are far easier and more foolproof ways than manipulating fuel switches. The fact that the aircraft was found in nose-up position also suggests pilots were trying to recover from descent triggered by engine failures.
The preliminary report’s loose wording added to speculation by not specifying exact cockpit wordings regarding fuel switches. More than one commander pointed out that if a pilot noticed manual action by his colleague, it would not be as mildly worded as the report suggests. There would be reasonable panic and aggression in words and tone.
Many senior pilots argued that the exact cockpit voice recorder transcript is necessary to rule out different scenarios and demanded it be made public. Aviation executives argued that selective CVR transcript release was proof that investigators were covering up real reasons behind the crash. “This reeks of creating a smokescreen to hide the real culprits,” a senior civil aviation ministry official said.
What remains unclear is why it took 10 and 14 seconds respectively for pilots to move switches from cutoff to run again. Since the report doesn’t specify when one pilot questioned the other, it remains ambiguous when he noticed it, questioned his colleague and acted to reverse it. By the time action was reversed, only engine 1 could recover and the aircraft wasn’t at sufficient altitude to reverse descent.
The Known Devil
Aviation industry executives argued post-report that the most credible cause was a design or maintenance flaw that led to fuel control switch malfunction or disengagement.
These executives point to past precedents. In December 2018, the FAA issued a special airworthiness information bulletin advising airlines on potential disengagement of fuel control switch locking features on Boeing aircraft including the Dreamliner. This advisory was not acted upon by many airlines including Air India. Post-crash, DGCA issued a mandatory compliance order.
That fuel cutoff switches have been malfunctioning was acknowledged when in January 2019, both engines of an All-Nippon Airways Boeing 787-8 similarly shut down after fuel cutoff just as it touched down. The aircraft had to be towed after stopping.
Executives also point out that it took two B737 Max crashes before Boeing publicly acknowledged and rectified problems. “If this happened with the B737, it’s more than likely this might be the case with the Dreamliner as well,” said a senior IndiGo commander. Given Boeing fuel locking system history, it’s surprising the report recommends no actions to B787-8 and GE GEnx-1B operators and manufacturers. “This leaves open the possibility of a second accident based on the same issue. Do they actually seek a repeat before action is mandated?”
Immaterial Yet Very Material
An aura of mystery and lack of transparency has enveloped the investigation from the beginning, angering the aviation industry. Questions have been raised by airline CEOs, former bureaucrats, former DGCAs and ministry officials.
Why was the preliminary report released at midnight instead of with a press briefing allowing questions that the airline sector, crew and passengers’ families require and deserve? “If there’s nothing to hide, there’s no explanation for this cloak and dagger approach,” says a former civil aviation secretary, adding this long-standing problem needs review. India needs to change its approach and tighten systems not only to prevent accidents but equally in how it investigates and recommends future prevention actions.
Valid questions have been raised about the scanty one sentence from cockpit voice recording. “Why disclose only one line from the CVR and not the rest? And if it’s controversial or likely to cause unwanted speculation, why mention anything at all?” asked a former Union minister, arguing sketchy details and loose wording have left the investigation more clouded in mystery.
Perhaps most galling is that the report neither specifies who was involved nor is signed, which many argue undermines credibility. “This is like saying we have investigated but don’t find it worthy of signing and attaching our names to,” points out a former IATA official.
At a macro level, India appears to have once again failed its citizens by releasing a report not worthy of a country with its stated ambitions.