"I haven't heard of an uncommanded application of reverse thrust on a 747 before, but it is just as well that it didn't occur in the air, as happened to the Lauda Air 767 some years ago, when the wing was ripped off."
TATprobe: The B767-300 wing was NOT ripped off...!
Subsequent large
control inputs applied during flight at speeds in excess of the airplane's operating envelope had induced structural loads in excess of the ultimate strength of the airplane structure.
Because corrective action [No 1 thrust lever to idle, application of right aileron/rudder to maintain level attitude] was not initiated within 6 seconds, the airplane had rolled beyond 90 degrees [on its back] and into a dive. Analysis of the major structural damage showed that the failures were the result of buffeting,
maneuvering overload, and
excessive speed. Parts of the airplane that separated were pieces of the
rudder and the
left elevator..."
In flight reverser deployment by itself did not cause structural failure.
For comparison, there are other airframe makers, among them the McDonnell Douglas DC-8, where maximum reverse thrust may be deployed IN FLIGHT on the inboard engines.