What theory? That the mount failed? Or the rotation of the engine in the photos going up and over the fuselage?

It seems like both are true, but doesn't necessarily prove WHY the mount failed.

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.

That the engine was flung into the fuselage due to gyroscopic forces.

Well, some force flung it inboard and above the fuselage (gods, that CCTV stills sequence.) Knowing that the engine rotates CCW, there are not many candidates.

> Knowing that the engine rotates CCW, there are not many candidates

There are lots of candidates for a failing engine yeeting itself in any direction.

> There are lots of candidates for a failing engine yeeting itself in any direction.

For the precise trajectory, certainly; for the general direction, not so much. Could you describe a combination of forces that would have thrown that engine to the left of the direction of travel? (We're talking about this accident, not any engine anywhere.)

> Could you describe a combination of forces that would have thrown that engine to the left of the direction of travel?

Foreign object gets yeeted to the right. Internal component gets yeeted to the right. Engine exploded on its right side.

I think each of those is more likely than gyroscopics since the engine went to the left. Not left and up.

> [...] the engine went to the left. Not left and up.

Whatever you're describing, it's not this accident. Over and out.

You're correct–I didn't look at the photos.

My broad comment is that gyroscopic precession having any critical role in this is incredibly far fetched. That said, I've never flown or worked on a turbofan so ¯\_(ツ)_/¯.

Gyroscopic forces might have changed the direction of travel a few degrees, but the motive force comes from the engine's thrust, the power of its spinning blades pushing air. An engine cut loose at full power moves forward like a missile.

I'm presenting it "useful not true" - not an RCA.

This is a preliminary report. Its purpose is to present initial evidence/information.

The final reports are always much more comprehensive.