Destruction due to turbulence when below Va - how?

"William W. Plummer" wrote

Metal fatigue, cracks and construction defects are not caused by
turbulence although turbulence may be the straw that breaks the
camel's back when those problems exist.

IIRC the Convair Electra was the first plane that metal fatigue was
determined to be the cause of its wings coming off. And, it took
years. What caused the fatigue? Gyroscopic motion of the wings.

Turbulence most certainly is the cause of fatigue in the wing
structure of aircraft. I would suggest that you read FAR Part 25
to understand how the nature of the Standard Atmosphere and the
cruise speed is used in designing a "fatigue life" in transport
category aircraft.

"Convair Electra"??? No way...my Electra time was flown in a
Lockheed Electra..L-188 and it's US Navy derivitive the P-3 Orion.

The civilian L-188s failed early in their service life, Braniff's
Flight 542 crashed in 1959, only two months after it's delivery
from Lockheed. The Northwest Flight 710 crashed in 1960 after
only one year in service.

It was not "gyroscopic motion of the wings" nor "fatigue".......

"On May 12, 1960, Lockeed President Bob Gross announced that both
airliners broke-up due to an undampened propeller whirl mode that
produced destructive flutter of the wing."

This from the "Great Airliners Series, Volume Five, Lockheed 188
Electra" by David G. Powers.

You disappoint me William.

Bob Moore
Air Florida L-188 1973
VP-46 P-3B 1965-67