By Ayaskant Das

New Delhi: In a major boost to ‘Make in India‘ in the defence sector, the Indian Air Force (IAF) will soon put forward a proposal for procuring the indigenous basic trainer aircraft, Hindustan Turbo Trainer 40 (HTT-40), from the state-run Hindustan Aeronautics Limited (HAL).

Senior IAF officials said inputs have been sought from the HAL for formulating a statement of case required for revalidating an Acceptance of Necessity (AoN) by the Defence Acquisition Council (DAC) chaired by Defence Minister Rajnath Singh. This month’s DAC will meeting later this week.

The IAF has fallen short of basic trainer aircraft after the indigenously manufactured Hindustan Piston Trainer-32 Deepak (HPT-32) were grounded in 2009 following a series of accidents leading to loss of lives.

At present, the existing strength of trainer aircraft — including basic, intermediate and advanced trainers — with the IAF is 260, as against the sanctioned strength of 388. This includes 75 Pilatus PC-7 MkII aircraft used for the purpose of basic training.

“A committee has been constituted with the representatives of the Defence Research and Development Organisation and the Air Headquarters to finalise the documents required for verification of the indigenous content of the HTT-40. The HAL is in the process of providing these details to the IAF including cost of aircraft, support package and simulators,” said the official.

Last September, the HAL had successfully conducted a rigorous ‘six-turn spin test’ on a prototype of the HTT-40. The aircraft had returned to its original position each time after being thrown into multiple spins, which was termed as a landmark development by the HAL in the design and development phase of the aircraft.

In November 2019, Chief of the IAF, Air Chief Marshal R. K. S. Bhadauria, had undertaken a test flight of the HTT-40 from the HAL’s airport in Bengaluru, Karnataka to ascertain the flight worthiness of the aircraft and its standards for training new pilots.

The test flight by the Air Chief had fuelled speculations that the IAF would soon float a Request for Proposal (RFP) with the HAL for the aircraft. According to the IAF, the RFP is likely to follow the Acceptance of Necessity is revalidated by the DAC.

According to the HAL, the design and development of the HTT-40, which is undergoing ‘spin’ phase testing at present, will be completed by June this year. The HAL is working towards completing the certification process of the basic trainer by meeting all parameters that have been required of it by the IAF.

“In February 2010, the DAC had accorded an approval for the design and development of an indigenous basic trainer aircraft by the HAL. The DAC had also approved the procurement of aircraft by the IAF. The maiden flight of the prototype aircraft took place in the year 2016 nearly after three years of delay,” the IAF official said.

Apart from giving the go-ahead for the development of a new indigenous trainer to replace HPT-32 Deepak, the Indian government had also decided on an off-the-shelf purchase of basic trainers to meet immediate requirements.

Subsequently, in 2012, India signed up for the Swiss aircraft manufacturer Pilatus Aircraft Limited to procure 75 ready-to-fly PC-7 MkII at a cost of Rs 2,800 crore ($437.5 million, at then currency exchange). Pilatus completed delivery of all 75 aircraft in July 2018.

However, a clause in the contract with Pilatus giving IAF the veto for purchase of an additional 38 aircraft was never exercised. The deal was mired in a controversy over involvement of an arms dealer in the award of the contract and Pilatus was blacklisted from doing business with the Indian Ministry of Defence.

The option clause, which was being processed at the time the controversy erupted, has now been deferred.

Flight training for pilots commissioned into the IAF has meanwhile been far from ideal with the defence ministry remaining non-committal on a timeline for the manufacture and induction of basis trainers.

The Parliamentary Standing Committee on Defence had noted the “conspicuous silence” of the ministry regarding the induction of the HTT-40 into the air force in its 47th Report tabled in Parliament of India in Jan. 2019.

“The delivery of contracted volume of 70 BTA with HAL is planned to be completed over a period of five years post signing of the contract. As the trainer aircraft HTT-40 is yet to obtain certification even two years after first flight of prototype-I and the contract is yet to be signed and the [Defence] Ministry’s reply is conspicuously silent as to when the trainer aircraft is finally pressed into service, the Committee feel that IAF may have to persist with the shortages of trainer aircraft in the foreseeable future,” the report had stated.

In the absence of adequate number of basic trainers, simulators are being used by the IAF for imparting flight training. At present, the IAF has two fixed base full mission simulators, three cockpit procedure trainers and one avionics part task trainer along with associated equipment and infrastructure for the basic trainer aircraft.

Air Chief Marshal Bhadauria had made it clear in October 2019 that plans to acquire the additional 38 aircraft from Pilatus have been dropped while the focus will remain on indigenous development of aircraft.

The latest report of the Parliamentary Standing Committee on Defence, which was tabled in the Parliament in December 2019, was more categorical in its study of the lack of trainer aircraft with the IAF and the problems thereof. The defence ministry had laid the blame upon the HAL for delay in completion of the project.

“… the timeline projected by HAL for the development of HTT-40 was three years (February 2013) for the first flight and five years (February 2015) for the certification. HAL achieved the milestone of first flight in May 2016 with a delay of over three years,” stated the report.

The HTT-40 aircraft is designed around a turbo-prop engine TPE-331-12B, which is manufactured by the US defence firm Honeywell. The HAL has made it clear in the past that the engine requires an upgrade from its manufacturer, but it has been reluctant to release the money until it finds buyers for the aircraft.

The latest report of the Standing Committee on Defence has reiterated the need for an engine upgrade in no uncertain terms while also factoring in that this could result in further delay in delivery of the aircraft.

“Aero Engine Status Engine Electronic Control (EEC) has become obsolete. For the production versions of the aero-engine for HTT-40, a new EEC/twin channel FADEC needs to be developed. M/s Honeywell has quoted a time frame of 24 months from T0 for this task. Presently the flight testing is being done with Cat ‘B’ EEC,” states the report.

The defence ministry had informed the standing committee that during a review meeting of the programme conducted in August 2019, the planned date for completion of certification was fixed as April 2020 following which IAF would take forward the case. However, the HAL has now fixed June 2020 as the deadline for completion of design and development of the aircraft.

The HTT-40, which can be used for training and aerobatic purposes other than night flying, has a maximum range of 1,000 km and a top speed of 450 mph.