I misspoke, which is a kind way of saying that I forgot, it was Pratt &
Whitney, Wright and Allison. The name of the book that I have for
reference is the "B-17 Flying Fortress in Detail and Scale" by Alwyn T.
Lloyd, part 2, the Derivatives. P&W tested the 5000 hp XT-34
turboprop, Wright the 5500 hp XT-35 (and used it to test the R-3350
radial), Allison the 3750 hp T-56 turboprop. An "Air Combat" magazine
B-17 special edition dated Fall, 1985 has another pic of the P&W Fort
flying on the turboprop alone and a pic of another B-17 modified for
testing a pure jet in a pod under the nose. The detail and scale
series are published by Aero, a division of Tab Books, and are for
modelers to use making scale models. They're pretty interesting if
you're a B-17 nut, like I am. Herb






There were three B-17 airframes after the war that were given to
Curtiss-Wright, GE and Allison for testing turboprops. The one in the
pic is (I believe) the Wright engine, it was a 5500 hp turboprop,
they'd take off on the Cyclones, start the "5th engine" and then
feather all 4 Cyclones and fly on the turboprop. There's a fair write
up in some of the modelers books that I have, will have to put the
reference in later. One of the "5th engine" test beds actually had a
jet engine mounted in the nose position with the discharge under the
plane. The Wright test bed was donated to the New England Air Museum
where it was severely damaged during a tornado in 1979 if I remember
correctly. The airframe minus the engine mount was traded to a war
bird restorer in Kissimmee, FL in exchange for the restoration of
NEAM's B-25J. My understanding is that the airframe has been rebuilt
and restored to original flying airworthy condition. I'll add the
reference for the pics and some more info on the test beds tomorrow
morning when I get home.
Herb