What happened
A newly acquired aircraft, which had been stationary at a regional airport for several months, was undergoing a performance evaluation flight. The mission, conducted by two test pilots, aimed to monitor fuel and oil consumption levels. To extend the duration of this flight, extra fuel tanks had been placed inside the cabin.
During the cruise phase at a low altitude, the crew reported a fire originating within the cabin to air traffic control. In response to the emergency, the pilots attempted an immediate landing. The aircraft type impacted a field approximately 15 miles from Madras, where it caught fire and was destroyed. Although the two pilots successfully evacuated the wreckage, there were no injuries reported.
Findings
Investigations revealed that the supplemental fuel tanks positioned in the cabin were not properly sealed, leading to active leaks. It was determined that the technicians responsible for the installation were aware of these leaks but proceeded with the flight because they could not identify the specific source of the leakage. The fire was triggered when leaking fuel came into contact with an unidentified heat source within the cabin, making the continuation of the flight impossible.