HTT-40 Powerplant and Other Details

A model of the HTT-40 on display at HAL pavilion at DefExpo 2014

Far from being rattled by the IAF's lack of enthusiasm for the HTT-40 as a Pilatus PC-7 Mk-2 replacement, HAL is pushing ahead with the development of the turboprop powered tandem twin seat basic trainer.

An HAL rep told IDP Sentinel at the DefExpo that HAL is committed to obtain certification for the aircraft within 3-year of project sanction.

The aircraft will be powered by a Garret TPE 331-12 turboprop. HAL in 2009 tied up with Honeywell to manufacture the engine in India for international markets.

HAL has been manufacturing, repairing and overhauling the Garret TPE-5 for international clients under license from Honeywell since 1988. Besides many other aircraft, the engine also powers HAL manufactured Dornier DO-228 aircraft.

The TPE-331-12B powers the Short Tucano basic trainer of the RAF. The engine has a power output of 1,100 shp (820 kW).

HTT-40 at Aero India 2013

The Max T/O weight of the HTT-40 is < 2,800-kg, It has a range of 1,000-km, service ceiling of 6-km, G limit of +6 to -3 and a normal operating speed of 400 kph. The aircraft will feature modern avionics and zero-zero ejection seats.

Assuming that the TPE 331-12 engine is only marginally different from the 331-12B, HTT-40 performance figures don't compare well with those of the Short Tucano.

HAL proposes to develop a weaponized version of the HTT-40, which may tip the scales in favor of the aircraft over Pilatus PC-7 Mk-2 in MOD, the IAF's skepticism not withstanding.

The GOI sanctioned the purchase of 181 basic trainers to replace HPT-32's following their grounding in July 2009. Following global bidding, GOI approved procurement of 75 Pilatus PC-7 Mk-2 aircraft in May 2012. Pilattus on May 24, 2012 announced that it had signed a 500 million Swiss Franc contract with the IAF to supply 75 PC-7 Mk-2.

HAL wants to meet the residual order of 106 basic trainers with its HTT-40 aircraft, instead of locally producing more Pilatu PC-7 Mk-2 at its facilities in India, but the IAF doesn't want to strain its resources by inducting another aircraft type. It is also wary of HAL's ability to deliver, following the HPT-32 experience. In view of HAL's reluctance to manufacture the aircraft, the IAF in early 2014 proposed manufacturing the Pilatus at its own facilities.

HTT-40 Basic Flying Trainer (IDP Sentinel)