Re: Configuration Warning Sys at T/O

From: (Richard Shevell)
Organization: Stanford University, Dept. of Aero/Astro
Date:         01 Feb 95 08:24:37 
References:   1 2 3 4
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In article <airliners.1995.82@ohare.Chicago.COM>, polo@SEDS.LPL.Arizona.EDU
(Tomasz Natkanski) wrote:

> Martin at Staffs University, UK ( wrote:
> : R. Solene wrote:-
> : >After all, didn't the cockpit crew of a Northwest MD-80 forget to
> : >extend the wing flaps (via mechanical actuation) just prior to take-off
> : >causing a crash and the deaths of some 160 passengers?  
> : SURELY that can't happen any more!  I thought that after the BA 747 crash 
> : at Nairobi, in the 70's, full takeoff configuration warning systems
> : were mandatory, in all ICAO states?   They would sound a siren if
> : anything was amiss (flaps, slats, speedbrakes, spoilers etc) when
> : the throttle was advanced for take-off?  

The Northwest MD-80 had a previous flight that day with a prolonged taxi
after landing.  Every time they had to advance the throttle to taxi
further, the siren  (or horn) sounded.  Annoyed, one of the pilots reached
up and pulled the flaps-up warning circuit breaker, and forgot to reset it
later.  On the subsequent takeoff (I do not know if it was the same crew) a
tower communication interrupted the check list routine just before the flap
setting item.  When the crew got back to the check list, they returned too
far down the list and missed the flaps.  And the warning horn had been
disabled.  As with most accidents a double failure plus fate was
responsible.  The horn check had been a checklist item only for the first
flight of the day.  I believe that after this accident Northwest added the
horn to the standard pre-takeoff list. 

> I was once on a Lufthansa flight from Warsaw to Frankfurt and the A 310 
> we flew in didn't extend flaps during take off. Nothing happened, we got 
> airborn without any problems despite the fact that the plane was almost full.
> Does anyone know if this practice is common for A 310 and perhaps for 
> other airliners?

Many twin engine transports with leading edge slats at high takeoff weights
use small or zero flap angle for takeoff.  The slat is a powerful tool for
increasing the maximum lift coefficient, and thereby reducing the stall
speed, all by itself.

Richard Shevell