In article ,
Dudley Henriques wrote:
Really getting nitty here Hilton :-)

With the engine dead, and assuming good rigging, there is no specific
reason to assume a spiral. The initial question specified the engine
"quit". Again, assuming proper trim and no aerodynamic forces to induce
bank, the aircraft for all practical purposes anyway, can be assumed a
straight path into the ground.

Take out the proper trim and an idling engine and perhaps you have a
case for a spiral. Also, few aircraft are rigged perfectly so that also
could be a factor for a spiral.

Turbulence would increase the likelihood of a spiral departure from
level flight, wouldn't it?

Other than these things being present and considering the "spirit" of
the question, trim speed would be the answer for ground impact in my
opinion.