Originally Posted by
Checkboard
There were rumors and possibly some that admitted to knowing the technique to pulling a certain CB, name escapes me, which allowed some flap extension without leading edge devices to allow high altitude cruise. But there were two CBs associated with the leading edge devices. LEFUS rings a bell and I don't remember the other one but if you believe the rumors the FE was told to pull one and it was the wrong one. There is no doubt that if you pull the right one you will get flaps without LEDs.