Re: 4-point Landing Gear Aircraft

Date:         22 Jul 99 23:30:36 
From:         "Tim Lee" <tim.j.lee@btinternet.com>
Organization: BT Internet
References:   1
Followups:    1
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James Fu wrote in message ...
>Why is it that pilots of aircraft with 4-point landing gear systems (nose,
>center, and one each main) sometimes deploy only the nose and main points,
>and not the center?  Naturally, aircraft like the MD11, DC10, and A340 are
>the referenced aircraft here.

Think you'll find that the choice is not there - I can assure you that
the A340 CLG (centre line gear) is fitted to each and every A340, and
extends and retracts with the mains - every time.  The DC-10 pilot has
no choice either - some variants have it, some don't - if they do, the
crew are stuck with it.  It all depended on the MTOW (max take-off
weight) of the aircraft.

BTW, the A340 CLG hardly touches the ground with the aircraft empty....
not a well known fact, but if you ever see one empty (zero fuel) you may
even see daylight under it.  It's just there to deal with the extra
weight of the A340 over the A330 (the main gears are identical for the
256 ton MTOW A340 and the A330, although the 271 ton MTOW A340 has a
beefed up MLG).  I guess that the later variants have even more highly
beefed MLGs - I left my job as a landing gear engineer on A330/340
before these heavies were developed....

Rgds

Tim