Doomed Air India Plane Issued Mayday Call After Take-Off

The cause of the first-ever Boeing 787 Dreamliner crash is still unknown but investigators hope to have answers soon. Officials say the digital flight recorder, one of the Air India aircraft's two black boxes, was recovered from a rooftop near the crash site on Friday, the AP reports.

• Greg Feith, a former National Transportation Safety Board investigator, tells the New York Times that investigators will have many questions: "Did they properly configure the airplane when it took off? What was occurring with them? Was there a loss of thrust? Was there fuel contamination? Fuel starvation where both engines weren't getting fuel that would have caused a loss of thrust on both engines?" Other theories include bird strikes or potential sabotage.

• The plane crashed minutes after take-off in Ahmedabad, killing all but one of the 242 people on board. India's civil aviation authority says the pilots issued a Mayday distress call soon after take-off but there was no further communication from the cockpit, the Washington Post reports.
• Video of the crash shows the plane descending with its nose still pointed up. It looks like "it should be climbing, and in fact it's descending," aviation safety consultant John Cox tells the Times. "The question is why."
• Sonya Brown, an expert in aerospace design at the University of New South Wales, tells the Guardian it looks like the plane stalled for unknown reasons. "It does look to me like a significant loss of thrust," she says. "Thrust effectively makes you go faster, and aircraft lift is proportional to speed squared, so if you don't have thrust and you lose speed—and radar data suggests after the initial short climb it was losing speed—you can stall." Possible factors, she says, include pilot error or improper maintenance on the 12-year-old aircraft.
• The black box recovered Friday will provide investigators with data on engine and control settings. "This should show quickly if there was a loss of engine power or lift after takeoff and allow a preliminary determination of the likely cause for the crash," Paul Fromme at the Institution of Mechanical Engineers tells the AP.
• India's civil aviation authority is leading the investigation and the NTSB has sent a team to assist.

(More plane crash stories.)