Cory6188 From United States of America, joined Feb 2004, 2686 posts, RR: 6 Posted (9 years 9 months 2 weeks 6 days 2 hours ago) and read 1895 times:
I noticed an odd sound coming from the engines of the CO 738 and 752 that I was on going to and from PVR, respectively.
Right after takeoff, a noise that could only be described as similar to a lawn mower began in the engines, and it did not quit until we were at crusing altitude. Could anyone explain to me what it is that I was hearing? I noticed this noise to be especially prominent when we flew on B6 last year, but I heard it for the first time on CO in April.
YWG From Canada, joined Feb 2001, 1143 posts, RR: 2
Reply 2, posted (9 years 9 months 2 weeks 5 days 7 hours ago) and read 1640 times:
I believe the engine sounds have to do with where exactly you sit in comparison to the engines position. I took 'the dopler effect' in gr12 physics last semester...and I believe this has a small part in it.
It's just the way the sound waves are compressed and meet with your head.
Avioniker From United States of America, joined Dec 2001, 1109 posts, RR: 11
Reply 3, posted (9 years 9 months 2 weeks 5 days 6 hours ago) and read 1635 times:
You gotta love "cut-and-paste"
The noise to which you refer is most likely the sound generated by the blade tips of the engine fan at high rpm with a relatively low impact airspeed as the plane accelerates. The sound fades as the plane reaches cruise speed and the throttles are pulled back.
And to all you high techies that is an extremely oversimplified explanation and was intentionally so...
One may educate the ignorance from the unknowing but stupid is forever. Boswell; ca: 1533