CAI DC10 Incident

From:         htsui@direct.ca (Herbert Tsui)
Organization: Private
Date:         31 Oct 95 00:31:35 
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In <46h64h$bgv@nnrp.ucs.ubc.ca>, downs@unixg.ubc.ca (Darren Downs) writes:

>During Takeoff, there was a problem with the left engine that has now
>been confirmed. (PErhaps a compressor stall? Unknown. Something to do

It has been confirmed that broken fan blades damaged the number 1
compressor resulting the engine to lose thrust probably causing a huge
shortfall in the EPR.

>The plane was at 155 Knots and about 1/2 way down the 11,000 ft runway

That's the part where I still don't understand.  155kts is quite high
(even given the DC10's MTOW but there are of course other factors that
I don't know about) to be below V1 (the decision speed) - it seems
that it's closed to Vr (rotation speed).  I would believe the the
Capt/FO would have executed a go-around instead of an abort unless the
engines were lacking so much thrust that they knew they wouldn't reach
V2 (airborne safety speed).

>when the takeoff aborted. I do not know the procedures for an aborted
>takeoff but I assumed that the reverse thrust was engaged and some sort
>of brakes on the wheels were applied. The brakes overheated and caused 8

I am not familiar with the DC10 but on the B744 we have an auto-brake
selector which is normally left in the RTO position (Rejected
Take-Off), it senses an aborted take-off and will engage the
auto-brakes automatically and believe me, there are very powerful. =)
And of course, as you have stated, the thrust reverser would also be
engaged.

>veared sharply to the right. I do not know if that was because all the
>tires were locked and it skidded off, or if the pilot was very smart and
>vered off the runway to avoid contacting the approach lights for Runway

It wasn't really up to the pilot, picture this, number 1 engine wasn't
producing a lot of thrust/reverse thrust and I believe the reverse
thrust mechanism on the number 2 engine was not operational leaving
only number 3 engine to provide the braking power.  This caused the
plane to go right and the rudder padels can only do so much.

>for.  People are generally unaware of how many maintenance problems
>planes have. A large airport can expect 2-10 delays a day for maintence

No plane is ever in perfect condition, as long as it's operating under
the MEL (Minimum Equipment List), there shouldn't be any problems...
well, maybe with the exception to this incident regarding the thrust
reverser on the number 2 engine.

>problems. Preliminary reports say that the maintenance was for the engine
>that had the problem on takeoff.

It sounds like the problem with the fan blades happened during
take-off since the Capt would have noticed metal fragments around the
number 1 engine during his walk-around.

Questions, questions, questions, so many questions.... =)

Cheers, Herbert

--
Herbert Tsui, Richmond, BC, Canada
htsui@direct.ca