Flight control systems involving a Boeing 737-377, VH-CZJ, Alice Springs Aerodrome, Northern Territory, on 21 July 1998

When the copilot rotated the aircraft through 17 degrees on the way towards the lift off body angle of 19 degrees the stick shaker activated. Concurrent with the stick shaker activation, the leading edge flaps extend light on the forward panel extinguished and the amber leading edge flaps transit light illuminated. As soon as the stick shaker activated the rotation was stopped. Almost immediately the leading edge flaps transit light extinguished, the leading edge flaps extend light illuminated, and the stick shaker stopped. The activation period was very brief and occurred at approximately 174 knots. 

The take-off and climb were continued normally and no other discrepancies were noted. Maintenance investigation disclosed that one of the leading edge slat position micro switches had failed. The failure of the switch caused the logic system to sense that the leading edge slats were retracted rather than extended. This resulted in the stall warning system being reset and the stick shaker to activate at normal take-off speeds. The operator advised that the manufacturer is considering a change that will ensure that failure of only one switch is insufficient to cause the system to be reset.