Re: landing flaps

From:         gallope@admin.curtin.edu.au (Ted Gallop)
Organization: Curtin University of Technology
Date:         17 Aug 95 04:58:51 
References:   1
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In article Susan Leibowitz writes:
>Subject: landing flaps
>Date: 14 Aug 95 03:43:26

>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.

Susan,
It doesn't make a lot of difference. There is no hard and fast rule. Normally
the gear is extended about half way through the flap sequence (about 4 stages)
as the aircraft slows. Once the gear is extended, drag increases immensely and
usually thrust has to be increased to control the deceleration.

The major influence as to when to drop the gear out of the traditional
sequence is the drag consideration. Possibly the pilots in your case when
given the landing clearance decided they had to slow down more rapidly
than they had expected. The easiest way to do this is to lower the gear.
Modern jets are awfully slippery, and if you are high on approach, and a
little fast, getting it slowed down takes a positive action such as the gear
method.

TG