Accident Overview
A training flight conducting stall tests at Karachi-Quaid-e-Azam Airport ended in a crash after both engines lost power simultaneously on final approach. The aircraft stalled, and despite the crew's efforts to regain control, it impacted the ground. The copilot sustained serious injuries, while the captain was killed.
Circumstances
The crew was performing local training maneuvers, specifically stall tests, in the vicinity of the airport. While on final approach, both engines ceased to operate at the same time. The aircraft subsequently stalled. The crew attempted to recover control, but the airplane crashed.
Investigation Findings
The official investigation identified the probable cause as overtemperature of both engines, which led to their simultaneous failure. This overtemperature condition was attributed to a malfunction of the contact switches in the No.1 engine propeller automatic flight safety pitch lock withdrawal system. Additionally, the pilot failed to manually withdraw the locks by placing the HP fuel cock levers in the 'lockout' position, as required.