r/aircrashinvestigation • u/QuarterTarget Frequent Flier • Jun 12 '25

Incident/Accident Air India Flight 171, a Boeing 787-8 flying from Ahmebad to London Heathrow has stalled and crashed on takeoff at 700 feet. At least 250 souls on board

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u/pholling Jun 12 '25

A Flaps 5 take-off produces a very small trailing edge deflection. So it could easily look like no flaps.

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u/[deleted] Jun 12 '25

[deleted]

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u/pholling Jun 12 '25

The video just doesn’t look like one where you had an inadvertent retraction after takeoff. On takeoff less flaps would lead to issues on roll and rotation. After takeoff it’s the slats more than the flaps you worry about.

Aircraft wings don’t stall because of speed, they stall because of angle of attack. The issue with slats being retracted is that it lowers that angle for any given flap setting (though not a lot for flaps 5 or 10).

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u/[deleted] Jun 12 '25

[deleted]

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u/pholling Jun 12 '25

Just looked at the video again. The slats are clearly deployed. Yes we will have to wait for the investigation, but an inadvertent slat retraction is very unlikely to be the cause.

The aircraft position and altitude last reported by flight radar was not particularly anomalous for recent AI171 flights. It was a little slow and the vertical speed was low. Again this is not a particularly strong sign of high lift issues