Originally Posted by
Jump Complete
Garrett turbo-props (fixed turbine) need turning by hand (15 blades / 3 complete rotations on the 5 blade Jetstream 41) after shut down for de-bowing.
Isn't it on the subsequent preflight rather than on shutdown? Surely you aren't interested in de-bowing if you don't intend to start it again.
On the Do228 with those nasty little high-speed Garrets you often saw pilots grab a blade and fling it to spin the turbine - when the point of that exercise was to start movung the propellor tip very slowly - very slowly indeed while listening for the turbine scraping. If no scrapes then continue turning at whatever rate was suggested - I forget.
Difficult (impossible) procedure to achieve on a normal noisy apron!