Re: 747 forward cargo door

Date:         13 Dec 96 04:26:01 
From:         Jean.Ludovicy@ping.be (Jean Ludovicy)
Organization: EUnet Belgium, Leuven, Belgium
References:   1 2 3 4
Next article
View raw article
  or MIME structure

"john r." <john@guava.demon.co.uk> wrote:

>If you have to put more air into the cabin to maintain pressurisation
>that takes it from the engine, via the packs, and so increases fuel
>consumption by reducing their efficiency.

I'm afraid , that's not the way it works. It's not the packs wich
regulate airpressure in the cabin, but the outflow valve. The outflow
valve just closes a little bit further to compensate for an additional
small air leak maintaining the avarage airflow through the cabin
constant, so no additional fuel is needed for that reason.

However....
>Also air leaking at the wrong place can cause drag.

Agreed!

Best Regards