Originally Posted by
vilas
The question asked is "In headwind conditions".
Exactly - as far as the engine is concerned, a 'headwind' is goodness - it simply increases the airspeed that the inlet sees.
Crosswinds and tailwinds are a completely different story - the air having make that sharp turn around the inlet lip at lower airspeeds can result in inlet separation - which in turn will probably result in a fan stall/surge. Very unpleasant and potentially damaging and expensive. So caution must be exercised advancing the thrust levers for takeoff.
The center inlet on 727s was somewhat notorious for that - fortunately the JT8D was darn near bulletproof - surges rarely resulted in engine damage. Years ago I was flying out of Seattle on a 727. As we started the takeoff roll, the center engine surged - I was sitting near the front of the aircraft but it was still so loud I nearly jumped out of my seat. After getting over the initial shock from the big bang, my thought was "Oh
- now I'll miss my connecting flight". But the pilot simply retarded the center engine thrust for a moment, then continued with the takeoff.
As I was getting off the aircraft in Salt Lake, I asked the pilot about it - he started into an explanation of what an engine surge was - I quickly stopped him, saying I was a propulsion engineer and understood all that - I was just surprised he continued the takeoff. He responded that if he'd aborted, they just would have gone back and tried again...
