Latecoere 631

[Karl]

Originally Posted by chris190

The failure of the type, apart from the incident of the propeller blades flying off and slicing into the fuselage, killing two passengers, seems to have been caused by the engine vibration frequency matching that of the airframe (think I have that right but see the on-line book I refer to earlier); this caused early fatigue and failures in ailerons and wings which I take to be similar to that of the Tacoma Narrows bridge which literally shook itself to bits.
Chris

That is still a problem on multi engined prop aircraft today. Even if it doesn't damaged the aircraft it does create fatigue in the crew.

[Yale]

Karl, in addition to the excellent points Chris makes, remember that the 631 was slow, cruising at just 200mph. The Lockheed Constellation was a contemporary -- although smaller, it carried almost as many passengers just as far, much faster, and had only four engines to maintain instead of six. The later DC6 was smaller, too, but carried even more passengers 100mph faster, and 1000 miles farther. So the 631 was overtaken by more efficient technology, even if these other aircraft lacked the 631's elegance.