Originally Posted by
bafanguy
Re TWA 841: I vaguely recall a theory floated at the time, wholly unverified, that there was a practice at higher FLs of pulling the Leading Edge Isolation Valve c/b and extending the fist notch of flaps to improve stability (increased wing area ?). The first notch moved the flaps mostly aft vs down. The max altitude with flaps extended is FL200 as higher altitudes were not flight tested for mach effects.
With the c/b pulled, movement of the flap lever wouldn't allow hyd pressure to reach the LEDs.
As the story went, the F/E returned to the cockpit, saw the c/b popped and reset it allowing the LEDs to receive hyd press and extend to match the flap lever position resulting in the event.
I have a problem with that theory: The event occurred at night (2148 local time). So, we're to believe that the F/E entered a dark cockpit at night and saw one c/b popped on the P-6 panel among a forest of c/bs...in the dark and reset it without comment to the crew ?
I just don't think that passes the plausibility test.
Not long after that event, we got a bulletin about slat droop at the gate with no System A hyd press on them (not Krueger flaps...they always drooped with out pressure). There is an allowed amount of droop before MTC action is required. The explanation of excessive droop had something to do with cracks being found in the slat actuator retract lock ring...or some other component with the potential to let a slat not remain retracted.
Admittedly, my recall is fuzzy but that's what I remember. aterpster ?
If the F/E found a popped CB, he should have first announced it before resetting it.