What does the autofeather do? (I know the basis function but what else):
-what triggers autofeather?
- does it reduce fuel flow to the "failed" engine?
- is the "objective TQ" increase a power up trim on the "working engine" or just a adjusted position of the torq bug requiring manual power increase on the working engine?
On my type, AF is triggered from either the AFU or the Engine control, (at takeoff both) it is triggered by a torque decreasing below 25%, the feather pump will run for 30 seconds and cause the failed engine to be feathered , at the same time the EEC will schedule more fuel to the remaining engine and Up trim it automatically, the bugs move automatically and the needles will match within a few percent.
The AF doesn't cut the fuel
we get 2.5 minutes at this setting, as i said its a different type but similar engine (PW126)