Re: Engine questions.....

Date:         28 Sep 97 20:59:09 
From:         alibi1reqd@aol.com (Alibi1reqd)
Organization: AOL, http://www.aol.co.uk
References:   1
Next article
View raw article
  or MIME structure

1 - The engine was windmilling thats all ... just the good old breeze
blowing through it .. the other engine was shielded possibly so it did
not spin.  Excessive windmilling can lead to blade root wear and of course
there is no oil pressure as the shaft spins too slowly and sometimes even
backwards so shaft bearing damage can occur after a very long time.

2 - Compressor stall occurs due to the air being presented at too high a
pressure or at the wrong angle to the subsequent stages of the compressor
stages ... it is in effect the same thing. Stalling or surging can occur
causing flameouts by allowing the hot gases to come forward.  Bleed valves
are used to tap off excessive air from certain stages deemed to have a
stalling tendancy to help prevent this.

Al B