Hi
Thanks for the responses. I kow the information is sketchy, but this is partly due to the availability of instrumentation. The aircraft is not specifically configured with data acquisition equipment, as the flight is merely meant to be a post-maintenance rather than experimental / development flight.
Due to the circumstances I was not able to have detailed discussions with the pilot. In a phone call he told me that:
- the aircraft felt "sluggish", as though the engines were not developing full power or there was an additional source of drag
- the aircraft had a definite tendency to roll to the left.
The aircraft was weighed prior to flight, and the CG was definitely within limits. The pilot trimmed the aircraft for level flight, and this required aileron trim (right wing down), and left rudder trim.
My immediate thought was that the controls were incorrectly rigged. These were checked against the specifications, and found to be correct. We also checked the engine and flight instrumentation, to ensure that the engines were developing the power reflected. All checked out correct.
That left me with structural deformities, which I have described above.
What concerns me is that the fin misalignment was not very large. I'm not sure that it could have accounted for the reported problems.