New Delhi, Aug 30 - The Indian Air Force (IAF) has grounded its entire fleet of HPT-32 initial trainer aircraft owing to a series of crashes and engine failures. This comes at a time when the force is facing an acute shortage of efficient pilots.

Authoritative sources in the IAF told IANS that recurrent engine failure of the Hindustan Piston Trainer (HPT)-32 aircraft - stationed at the Air Force Academy (AFA) in Hyderabad - is the reason behind the grounding since last month.

'The entire fleet of the HPT-32 has not been flying,' a senior IAF official told IANS, requesting anonymity.

The engine failures raised concern as the aircraft are handled by rookies for initial flight training.

On July 31 this year, an HPT-32 aircraft crashed at Annaram village in Jinnaram Mandal of Medak district and both the instructors on board were killed in the accident. In May last year a woman cadet of the AFA died during a crash. In this case fuel had leaked into the engine, causing it to burst.

The basic propeller-driven trainer, with two side-by-side seats, suffered more than 70 incidents between 1988 and 1995.

A group was constituted to study the aircraft, which is manufactured by the defence public sector undertaking Hindustan Aeronautics Ltd and which has been in service for three decades.

According to the study, the Avco Lycoming AEIO-540-D4B5 engine in the aircraft has registered more than 100 failures in recent months.