FAA:
This AD was prompted by analysis performed by the manufacturer showing that if an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer. We are issuing this AD to address this potential resulting nose-down trim, which could cause the flight crew to have difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain....
........do the Runaway Stabilizer NNC ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT
Early 707 training .... Capt. simulated a runaway stabiliser, nose down, student grabbed the wheel to stop rotation, called for switches to be cut off, and then for the circuit breakers on the overhead panel to be pulled, all in accordance with the drill of the era. The aircraft had set off down of course, and having correctly completed the drill, the Trg. Capt. called for the systems to be re-instated, but pulling back on the control column to reduce the descent, created so much "G" that the Flt. Eng. couldn't raise his hands far enough above his head to reach the circuit breakers. In the end, both pilots pulling, assisted by the Flt. Eng. placing his feet on the instrument panel and grabbing both control columns to assist the heaving they pulled out about 1200 ft above the water, having started around 5.000 ft. Sound familiar ? Maybe the CVR will confirm.