airnewzealand
Posts: 2310
Joined: Sat Oct 21, 2000 6:00 pm

Why A Dead Silence Beefore Engine Spoils Up?

Sat Jan 05, 2002 4:11 pm

Hey,
I have been at the airport quite aot lately, and i have noticed that especially on the bigger aircrafts..(esp. 747), before the engine are maxed out to full thrust, there is a period of no sound, or very very low sound...Could someone please tell me why this is!!??

Cheers
Mike
 
flightsimfreak
Posts: 698
Joined: Sun Oct 29, 2000 9:36 am

RE: Why A Dead Silence Beefore Engine Spoils Up?

Sat Jan 05, 2002 4:13 pm

Perhaps Tech-ops could help, but I think that the sound gets to a frequency that humans cannot hear. From my experiance, the pitch of the noise gets higher untill disappearing, then getting rumbly. This could be explaned that way. Don't kill me if I'm way off.
 
airnewzealand
Posts: 2310
Joined: Sat Oct 21, 2000 6:00 pm

RE: Why A Dead Silence Beefore Engine Spoils Up?

Sat Jan 05, 2002 4:31 pm

WOW,
i never thought of that...but yes i think that is a very likely scenario..and yes your way of describing it is exactly how it sounds!!

Cheers
mike
 
jhooper
Posts: 5560
Joined: Thu Dec 13, 2001 8:27 pm

RE: Why A Dead Silence Beefore Engine Spoils Up?

Sat Jan 05, 2002 8:02 pm

I've noticed that from inside the plane (especially the L-1011) numerous sounds such as the air conditioner go quiet just before the engines spool up. Maybe this is because maximum power needs to be available to the engines for takeoff. Can someone tell me whether or not this is true?
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