Re: B737 flaps

Date:         10 Jul 97 17:46:13 
From:         Patt <>
Organization: DFW
References:   1
Followups:    1
Next article
View raw article
  or MIME structure

duboille wrote:
> Who can explain me exactly the reason of the 20.000 ft limitation for flaps
> extension on B737 series.Many thanks in advance.

I flew 737-200's from '69 thru 87.. went to the 727, now back on

Anytime the flaps are not up, the airconditioning 'pack' fans come on to
increase airflow over the heat exchangers in each pack. The pack fans
are not needed at or above 20,000' (cool temperature at that altitude
and above) and more importantly, the pack fans could 'cavitate',
overspeed, overheat and start a fire in the air conditioning bay in the
centersection of the airplane.

The same restriction applied to the 727, which had only one pack fan
inlet scoop.  Although the 737 has one each intake (scoop) for each
pack, the restrictions still applies.

I apologize for the late post... just found this NG.

"Lemme hava Diablo sanwich ana Doctah Peppah..
  an make et fast.. I'm in a gawdam hurry!"