Re: SR111 findings

From:         tjbueld@netside.de (Thomas J. Bueld)
Date:         13 Dec 1998 21:52:55 EDT
Organization: Nacamar Group Plc.
References:   1 2
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Showing an extraction of the MD-11 Flight Operation Manual :

Engine feed system

"Each engine is normally supplied with fuel from its respektive main tank.
Tank 1 and 3, have 3 pumps each, 1 forward and 1 aft boost pump, and 1 transfer
pump.
The tail engine is fed from tank 2 which contains 4 fuel pumps, 2 aft boost
pumps, 1 forward boost pump and 1 transfer pump.

----Suction feed can be accomplished for the wing engines only.---

The transfer pumps supply fuel directly to the crossfeed manifold.
A DC powered APU start pump is also installed in tank 2.
In each tank, the pumps are all powered from different electrical buses.

--- In case of a total electrical failure, the LH aft boost pump in tank 2 can
be powered trom the air-driven generator (ADG)---"

---
Remark for the ADG "Air driven Generator":  This device is a kind of a
windmilled, additional generator, which can be extended into airstream to
produce AC current in case of all engine driven generators failure. The  ADG is
(almost) hardwired to the left hand aft fuel pump of tank 2. The ADG can be
used for restarting the No.2 engine after i.e. an "All Engine Flameout" due to
volcanic ash encounter or other reasons causing all engines to fail. It is not
likely that the SR Pilots had time to go through the respective action
checklists. Also, a failed engine is not a handicap for a save landing and
might not even be noticed by the pilots, if there is a complete instrument
failure or vision handicaps like smoke in the cockpit.
Additional engine driven pumps (by gear) can maintain sufficent fuel pressure
to the wing engines with the electric (Tank) pumps not working.
BTW I am an MD-11 Captain, flying this aircraft since 1991.

Dave Pullan schrieb:

> James Matthew Weber <jmweber@goodnet.com> wrote in article
> <366fe1d5.4321589@news.goodnet.com>...
> > 3). The No 2 enginer 'was not producing power when the engine struck
> > the water'.  It isn't clear to me what the meaning of this statement.
> >
>
> Could the no. 2 need an electric fuel boost pump, considering it is so
> above the fuel tanks while the nos. 1 and 3 are below?  If so, no electrics
> means no fuel (or can eng driven fuel pump suction feed this far?)
> Dave Pullan