On Wednesday, December 3, 1997 at 1:00:00 AM UTC-7, Dennis Gillman wrote:
I purchased Walt Lanes Turner T40 which appeared on the cover of SPORT
AVIATION January 1974 and HOMEBUILT AIRCRAFT June 1978. It had been stored
for about 15 years. It was restored and I have been flying it sense
November of last year logging 120 hours of trouble free FUN and FAST (200
mph at 2800 since). I discovered by accident on the computer, not
catastrophic while flying that the prop that it had on it, notice I said it
had on it, was cut down from a 74 inch diameter to 68 inches and repitched
to 68 degrees. this was a very popular prop in the 70s for home builders
particularly the T18 guys. the problem is this, the prop has a natural
frequency that is exaggerated by the rpm and frequency of the engine
(O290G). I was explained to me it is kind of like that bridge up north
that practically shook its self apart from the frequency that was set up by
the wind blowing across the wires, pretty scary if you saw the film clip.
just felt like passing that along to the general population of pilots that
may be flying these modified props. by the way, Sensenich say there isn't
any WARNING when it goes, no indication of cracking or anything. If your
flying one of these props you may want to give Sensenich a call.
Good Flying Dennis Gillman

Dennis Gillman - do you still own the Turner T-40 that Walter Lane built?????