Originally Posted by
LOMCEVAK
There was another asymmetric aspect to the Mk 104 engines in the F3 and that was the surge boundaries. At the tested conditions (21 AOA in a turn, and either slam max dry to idle and when just sub-idle reslam to max dry or slam max dry to sub idle, sweep the wings by one angle change then immediately reslam to max dry) for a given standard of DECU software one engine would always surge at a consistently higher airspeed than the other ie. was the 'critical' engine for surge. However, we did see that following one software upgrade (cannot remember which one) the critical engine swapped from one side to the other with no hardware changes inside the intakes at all. I never did hear a convincing explanation for this.
How interesting. Can you remember approximately when this was. And was it a repeatable event.
And when you say 'sub-idle' can you recall the actual NH.
And lastly, and I apologise for testing your memory, were both engines pilot levers moved in the same way at the same time.
Thank you and thank you for your post.