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Old January 19th 09, 07:51 PM posted to rec.aviation.piloting
RST Engineering
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Posts: 1,147
Default Jet Turboprop

I propose a technological solution to the problem of bird strikes:
turboprops.
Lets return to the good old days pre-jet engines.

Discuss.



One of the most prominent examples of a turboprop passenger aircraft was the
Lockheed L-188 Electra. It CERTAINLY came along well after a number of
"jet" passenger aircraft were put into service.

A turboprop, obviously, is NOT a jet but did get partial thrust from the
turbine exhaust. As I recall, the "jet" effect was somewhere around 10% of
the total thrust with the propellers providing the other 90%.

The aircraft suffered from early problems with "whirl mode" which took the
wing from two aircraft in flight. Whirl mode is the aircraft equivalent of
the Tacoma Narrows bridge effect (Galloping Gertie) in which resonance modes
that were not predicted in fact occurred. The effect was originally
attributed to severe turbulence, but a series of tests over the California
Sierra in turbulence classified as somewhere between severe and extreme
proved that prognosis wrong. One of our pilots (PSA) who helped conduct the
tests came back saying that "I swear to Almighty God that tin whore was
flying tail first for a while."

The Allison engine was a jewel, but from a maintenance and reliability point
of view, the propellers were a POS.


Jim
L-188 wrench 63-67