MarSch,long time retired...
you might want to read `AGARD ADA 173807`or search for earlier reports.
Also consider the tail rotor,and rear stabiliser,if high or low mounted;in/out of downwash/exhaust heating,possible stalling,affecting autopilot...similar to some work done on high mounted tailplanes ie ATR-42.
Last edited by sycamore; 7th Jan 2018 at 20:13.
Reason: been searching on gooo,,l