Wingdrop while stalling

drake wrote:

Hi,
there is a HAL HPT-32 (pistonengined 2 seater trainer light a/c)
which, when attempting a stall, does not pitch down correctly. Instead
one of the wings (either port or starboard (50/50)... no gyro problems
due to engine) almost always drops, and this genreally results in the
a/c entering a spin (which the rookie pilots are unable to handle,
generally). There is no inherent imbalance in the c.g. location due to
the fuel tanks ot fuel flow. What could be causing such a wing drop
while stalling? Is it soem inherent instability in the roll axis?

Sounds like a good rudder trainer.