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Old July 7th 03, 03:47 PM
Frank Minich
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The RA-5C's doors (nose and main) closed after gear extension.

The system was pretty nice in that on hydraulic failure all the gear would
free-fall after manual release, since all of the gear extended to the rear
(of course, the doors wouldn't close in this case). If I remember
correctly, it was a PMCF check to drop the gear manually (the non-essential
systems had hydraulic power removed when the the cockpit "hydraulic" switch
was in "flight" position) and then switch to "land" position and retract
them, just to verify operation.

Don't know why North American went to the trouble of retracting them - might
have had something to do with the airflow around the control surfaces, or
reducing drag for single-engine operation. The main gear doors were pretty
big - maybe they stood a chance of damage on landing - but the nose gear
door?

Frank

"Elliot Wilen" wrote in message
om...
In another online forum, it has been claimed that on the F-18, F-14,
F-4, and possibly F-8, A-7, A-6, and A-4, all the landing gear doors
stay open when the gear are extended. While typically (or at least in
most other military jets), some of the landing gear doors open only
during extension/retraction, and are closed while the gear are
extended.

Can anyone comment on the extent to which this is true? If so, there's
an obvious pattern of this characteristic appearing in fighter/attack
jets which were originally designed for the Navy. Is this due to Navy
"culture" or somehow related to a safety/reliability issue for
carrier-based operation? Or generally, is there some reason that some
jets are designed with gear doors that stay open, while others have
doors that close after the gear are extended? (The only reasons I've
seen that make sense are simplicity versus air drag and, in some
cases, ground clearance.)

Many thanks in advance.

--Elliot Wilen