a question for Thorp T18 owners

"Charlie" wrote in message
...
Stealth Pilot wrote:


are there any situations where a T18 will do other than a descending
dive after a stall?
also what aerofoil was used on your aircraft?

nothing sinister about this. we suffered a double fatality the other
day. there is a lot of utter nonsense floating around about this but a
perusal of a video take during the last minutes suggests that the
aircraft flipped over into a loop for some reason,the video then shows
that it rolled inverted during recovery and then made a ballistic
descent to the impact site.


I'm reasonably certain that I can explain the flight behaviour in
sound aerodynamic terms but I'm unsure of the initial stall behaviour.
the comment that the T18 can flip over onto it's back comes from two
T18 owners. are their aircraft typical or atypical?

I'd appreciate any first hand comment from T18 pilots.



Here is a comment from a friend who has built a Thorp T-18 and flies one
regularly.

The Thorp T-18 Has had several variants of airfoil and wings, Being a
homebuilt some have stall strips, some do not. So stall characteristics
vary. It is one of the very first "high performance" homebuilts and has a
laminar flow wing. A 'stock' T-18 has an abrupt stall break with ample
aerodynamic buffet as a warning. In a full stall it can easily drop one
wing very quickly. Trying to pick the wing up with aileron only can
aggravate the situation. A secondary stall on attempted recovery can occur
if over-aggressive stick pull is applied. The stall strips applied to the
inboard portions of the wing will increase the early warning buffet and also
soften the stall. Some Thorps pilots experienced a pronounce nose pitch down
or 'bunt' with full (40 degrees) flap. On later Thorps the flap travel was
limited to prevent this.
Accelerated stalls also occur at higher speeds & forces. Wing drops will
then also occur quicker. It is a very aerodynamically clean plane & picks up
speed QUICKLY when nose is pointed down. An excited pull on the stick can
bend things or stall the plane.
I am assuming this is the one that went down in Australia.. As I understand
the owner was fairly new to Thorps. The overall handling of a well built
Thorp is honest , but it is to be considered a high performance plane and
cannot be flown like a 172. Either way, my condolences to friends and
families of all involved.