Incident
While descending through 12,000 feet approximately 40 miles east of San Diego, California, the left overwing evacuation slide annunciator light illuminated. The slide separated from the aircraft about 7 miles east of the airport. No flight control problems were noted.
Investigation Findings
Examination determined that the evacuation slide system integrity was satisfactory, and the slide squib and actuator had not been activated. Evidence indicated that the integrator locking pin had not been fully seated, which allowed the latch shaft to move aft, causing the door latches to release. A modification performed on January 22, 1983, had involved changing the latch attach screws, a procedure that required unlatching the lock pin. Ambiguities were found in the installation procedure for the off-wing slide; the instructions failed to describe the mode of operation with respect to the turning directions of the latch-unlatch levers. This incident was the fourth in-flight overwing slide deployment.
Corrective Actions
In response to this incident, Boeing initiated a design change of the integrator mechanism. As an interim measure, compliance with Service Bulletin 767-25-5 was required by February 15, 1983.