HTT-40: The basic trainer

Indian Air Force is not only bedevilled with its fighter strength, even the easily available cheap Basic Trainer Aircraft are facing supply issues.

Whether to depend exclusively on the already inducted Swiss Pilatus and order the entire requirement of 181 for the rookie pilots of the IAF or to encourage the domestic manufacture of indigenous trainer by HAL, which has been designed and developed by the Indian aviation engineers, has been an issue between Vayu Bhawan - the headquarters of the IAF and the South Block, the integrated headquarters of the Ministry of Defence.

The indigenous developer of the aircraft the Hindustan Aeronautics Limited has been promising the IAF the domestic version the BTA designed and developed by them, yet the IAF has been paying scant attention to the indigenous BTT-40 trainer aircraft, displaying lack of confidence on the HAL on its ability to deliver the aircraft by not only fulfilling its technical requirement but on time delivery.

Of course, the HAL has been notorious for late delivery of its contracted air platforms. But  most recently the HAL authorities have indicated that after long delay, its Basic Trainer Aircraft the Hindustan Turbo Trainer-40 (HTT-40) will have its first flight most likely by the end of March or early April.

Defence Minister Manohar Parrikar has been pushing hard for the indigenous manufacture of the BTA, although capabilities already existed and much of the work had already progressed over the years of development efforts.

The HAL had already rolled out the prototype of the BTA in early January this year. The HTT-40 will be used for the first stage training for all flying cadets of the armed forces.

According to the senior officials of the HAL, the BTA trainers are about to complete the ground runs phase of the development process and first demonstration flight will take place by the second week of April.

On the insistence of the IAF, the previous UPA government had almost put a spanner in its final delivery to the nation’s armed forces, the present Defence Minister Manohar Parrikar insisted this project to be fast tracked on priority basis.

He told the developers that funds will not be a problem, as the MoD wants to achieve some concrete successful projects under the Prime Minister Narendra Modi’s Make In India programme, especially for the  defence sector.

The Defence Ministry is reported to have told the HAL that 70 BTAs will be ordered initially and all future orders will go to the HAL, instead of asking the Swiss Pilatus to continue supplies.

Comprehensive plan

In fact, the MoD is looking for its export potential and plans to heavily publicise its capabilities, though aviation market experts said that unless the HAL made HTT-40 is competitive in the international market it will have a very less chance of bagging orders.

Even the HTT-40 that will be supplied to the Indian armed forces will be costlier than the Pilatus PC7 Mk2, an issue flagged by the IAF headquarters and given credence to by the then UPA led MoD.

The Pilatus was acquired under the emergency purchase from Switzerland, as the decades old fleet of HPT-32 trainers were grounded on account of unacceptable rise in accidents killing young pilots.

At present, the IAF rely on three aircraft for three stage training of the rookie pilots-a basic trainer, the intermediate jet trainer and the advance jet trainer.

With the Kiran MkII intermediate jet trainer already on retirement phase and a replacement not available, the IAF had readjusted its training requirements to three stage two aircraft plan.

Though for the third stage of training the Advanced Jet Trainer Hawk is available in sufficient numbers, there is a shortage of basic trainers.

To meet its urgent requirement the MoD had sanctioned the emergency acquisition of 75 PC7 trainers, four years ago.

The IAF had projected the requirement of 106 more. The MoD had last year sanctioned the acquisition of 38 more Pilatus, the MoD insisted on acquiring the rest of the BTAs made domestically by the HAL which has claimed to have installed a very reliable foreign engine.

HAL had selected Honeywell in June 2015 to supply the TPE331-12B turboprop engines for the high-performance HTT-40 military trainer aircraft.

The TPE331-12B turboprop engine, equipped with full-authority digital engine control (FADEC) system, will develop a maximum power output of 950 shaft horsepower (shp).

According to experts, the advanced engine will enable the HTT-40 to offer users quick acceleration, low-fuel consumption, high-reliability and the flexibility to conduct a range of training missions.

The turboprop engine will also enable HAL to develop a range of variants that will present much better performance.

The IAF has claimed that the acquisition of Pilatus PC-7 turboprop trainers has revolutionised its first stage training programme.

Commenting on its before schedule delivery, the deputy CEO of Pilatus Jim Roche had then said, “Delivering and supporting IAF’s Basic Flight Training requirements have been a remarkable experience and we remain  fully committed to supporting the fleet’s in-service operations with equal efficiency and competence.” The first lot of PC-7s was delivered in 2013 within a year of signing contracts. IAF had projected a requirement of 181 basic trainer aircraft (BTA) out of which 90 were supposed to be bought off the shelf and 91 made in India.

However, the then UPA government decided to go for 75 aircraft contract with a 50 per cent follow-on clause. Besides Pilatus, the Russians had offered the Yak-152 which is a new-generation primary trainer aircraft developed by Yakovlev Design Bureau, which is a part of Irkut Corporation.

The HTT-40 is likely to begin production by 2018 and the serial production will start at HAL’s transport aircraft division (TAD) in Kanpur, India.

Several airframe structures have already been produced. It is a fixed-wing aircraft incorporating an all-metal airframe design and will consist of a bubble canopy, T-tail configuration and a retractable tricycle landing gear system with a steerable nose wheel.

The HTT-40 will be mainly used for basic flight training, aerobatics, instrument flying and close-formation flights.

It will also be used in its secondary roles like navigation and night-flying. HAL officials claim that the HTT-40 trainer will offer the best-in-class fuel economy and power rating.

It will take-off from a short distance and have a high rate of climb. It will have a maximum speed of 450km/h and reach a maximum distance of 1,000km.

The stall speed with flaps down will be 135km per hour. The certified operational ceiling of the trainer will be 6,000m, the ‘G’ limits will be +6/-3 and airborne endurance will be three hours.

The Chief of IAF Air Chief Marshal Arup Raha, while addressing the customary annual press conference on the Air Force Day last year had accepted the HTT-40.

“As we get the HTT-40, indigenously built by HAL as a basic trainer, I think we will be well on our way in making up the deficiencies in our pilot training.”