What happened
During the descent phase of flight while approaching for landing, the flight crew experienced a temporary and unintended deployment of the left engine's thrust reverser. Due to this event, the crew declared an emergency and diverted the aircraft to a nearby airport. The airplane landed at the diversion airport without any further incident.
The investigation
An examination of the thrust reverser control system was conducted following the event. Investigators found that moving the thrust lever aggressively to the aft stop could cause the left engine's thrust reverser switch to actuate.
Further inspection identified mechanical faults in two specific components: the left main landing gear Ground/Flight (G/F) switch and the left engine thrust reverser deploy switch. Following the replacement of both the left main landing gear G/F switch and the thrust lever switchbox, the aircraft's thrust reverser system passed testing and was confirmed to be functioning correctly.