[edwinland]

According to the news reports, it took 8 minutes to descend 32,000 feet before hitting the mountain. That’s a rate of 4,000ft/min. That’s a very steep decent. What I would like to know is at what speed would the plane break up in midair. The debris field looks too wide for a mountain impact.

Good question does anyone know the answer?

And note the intriguing clue of an impact before the main impact.

Did the plane clip the top of an earlier mountain? But then wouldn't they have noticed that by now?

Or did it hit another object before striking the mountain? A bridge? It doesn't look like there are any bridges in that area. A tree? Would it be big enough to cause that impact noise? Or another airplane? Another airplane couldn't be civilian because we would have noticed the disappearance so it would have to be military. Was that the object?

[smokingfrog]

It’s possible that he chickened-out or tried to pull up at the last few seconds and overstressed the aircraft causing it to break-up?

[painter]

If he flew straight into a mountain even solid granite shouldn’t there be an impact point.

[diogenes ghost]

4,000 feet per minute is NOT a "very steep decent".

As an ATC, I would have no problem assigning a descent requiring 4,000 fpm. If I needed more, I would add the phrase "if feasible, if not, advise".

As a jumpseater, I have been in a descent of 9,000 FPM in a 727...THAT was steep.

Also, rate of descent is not what causes in-flight breakup, it's overspeed or excessive stress from maneuvering