Ravi Sharma

BANGALORE: The board of inquiry constituted by the Directorate-General of Civil Aviation (DGCA) has completed its investigation into the March 6 crash of the Light Transport Aircraft Saras near Bidadi in Karnataka.

Two pilots and an engineer, all from the Indian Air Force’s Aircraft and Systems Testing Establishment, were killed in the crash of the Prototype Two (PT2).

An official of the National Aerospace Laboratories (NAL), designers of the Saras, said the DGCA had promised to make the report available before month-end.

The Hindu has learnt from officials connected with the board of inquiry that the engine relight (engine restart) drills given by the designers and followed by the pilots were wrong.

The two test pilots were for the first time on the Saras, attempting to switch off and relight in midair one of the two Pratt and Whitney (PT6A-67) engines. The test is a mandatory requirement of the flight development programme. The aircraft had reached its designated height of 9,000 feet and the left engine switched off. After one minute, the crew attempted to relight the engine, and this was communicated to the ground crew. But soon after radio communication was lost, the aircraft started losing height and crashed. “Prior to the flight, the pilots were briefed by the designers about the drills to be followed during relight, and they followed it. But the relight drills were incorrect. With each aero engine having its own unique set of procedures to be adhered to during relight (like at what speed, airflow, where the propellers stop, etc), the pilots just followed the designer’s briefings. Errors occurred; the aircraft went out of control and crashed,” an official explained.