← Back to context

Comment by scottlamb

19 hours ago

Not an aviation expert at all, so take this with a grain of salt, but I think "the spinning engine resists changes to the direction of its spin axis" offers two important insights:

* why it failed at rotation (the first/only sudden change of direction under full throttle) rather than as soon as it was mounted onto the plane, while taxiing, as soon as they throttled up, mid-flight, or on landing. This is important because at rotation is the worst possible time for this failure: no ability to abort take-off, no ability to land safety under no or severely limited power, little time to react at all, full fuel. Knowing these failures are likely to manifest then stresses the importance of avoiding them.

* why it failed in such a way that it damaged the rest of the plane.

Not so much what was wrong with the mounting in the first place, if that's what you're asking. Presumably it was designed to withstand the forces of this moment and clearly has done so many times before.

> Presumably it was designed to withstand the forces of this moment and clearly has done so many times before.

The report seems to suggest metal fatigue in the motor mount may be a possible culprit.

  • Not the motor mount but the pylon mount. The pylon was found attatched to the engine with both engine mounts attached.

    But yes, the report mentions stress factures where the aft pylon mount failed.