Re: DC-10-30 (and -10's ??) #2 Thrust reverse useage

From:         peter neville gurnell <pgurnell@direct.ca>
Organization: Internet Direct
Date:         08 Feb 96 03:21:06 
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Steve Lacker <slacker@arlut.utexas.edu> wrote:
>
> randl@direct.ca wrote:
> > Why do some airlines consistently use reverse thrust
> >on all three engines, yet in contrast, others only use #1 and #3 reverse?
>
>

According to the DC-10-30 F.C.O.M. Vol.III p.17-10-03 (This should be
in my instantly retrivable data file, but it isn't) to quote para. 3
of the description of the T/R system, "An in-flight reverse thrust interlock
prevents deployment of the thrust reversers unless the landing gear is
down.  After landing gear is down, initial reverser lever movement un-
locks the respective system, starts reverser deployment which is indicated
by the REVERSER UNLOCK (easily visible) and REVERSER VALVE OPEN lights
(situated where no-one is looking) coming on.  The reverser system, when fully
deployed, will release the reverser lever interlocks for engine 1 and
3. (Here is the important part) For engine 2 reverser lever interlock
release, full reverser deployment and ***NOSE GEAR*** ground shift
(gear squat switch) mechanism actuation is required.

ie:  You can pull 1 & 3 into reverse as soon as the mains are on but
you have to wait for the nosewheel to touch to get #2 out.

I work for a company that has used both methods over time.  You do not
get a noticeable pitch up from using #2 in reverse however the Douglas
manuals state that below 60 kt. the thrust vector from #2 in reverse is
actually forward!!  I believe that our S.O.P's consider T/R usage a
"technique item" but most, if not all of our crews pull 1&3 out and
into reverse then deploy #2 later(usually 4-5 seconds to get nosewheel
on the runway.

DC-10, Voodoo Engineering, Fly-by-mouth but built like a brick
shithouse.  BTW, S.O.P. on the 10 is folklore and innuendo.

				Peter N. Gurell,
				S/O, F/E DC-10-30
				Canadi<n Airlines Intl. YVR