Re: landing flaps

From: (Edward Graf)
Organization: The Pipeline
Date:         17 Aug 95 04:58:49 
References:   1
Followups:    1
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In article <airliners.1995.1219@ohare.Chicago.COM>, Susan Leibowitz

>Is it unusual to not extend the wing flaps until after the landing gear
>has been deployed?

>When I was coming into LAX the other day on a 737, we were cleared to
>land (I was listening on the headphones to ATC), when the gear was
>deployed....and then the flap were extended.  I wanted to ask the
>pilots but they never came out of the cockpit.

>thanks...from a slightly scared flier


I fly the 737-300 out of LAX.

The aircraft must be slowed up from it's normal 250 knots (below 10,000')
in order to get any reasonable descent rate.  Although hardly possessing
the sleek characteristics of a glider, it sure acts like one.  The
speedbrakes are relatively ineffective, generating more noise and shaking
than actual additional descent rate.  The most effective source of drag in
the 300 is the landing gear.  The gear can be deployed at 270 knots,
whereas flaps (in the 300) can be started out no faster than 230 knots, and
are not nearly as effective as the gear.

The above, coupled with ATC's need to mix you in with other aircraft
capable of brick-like performance and 250 knot speeds can often result in
speed brake and gear deployment sans flaps.

No need to be afraid, there was nothing unsafe with the approach.  The
pilots staying in the cockpit?  Probably haggling over who got the best
landings on the trip.(grin)

Ed Graf