The HTT-40 Story: IAF Is Finally Buying Made-In-India Trainer Aircraft It Refused To Buy Into For Years

The Cabinet Committeee on Security has approved the purchase of 70 Hindustan Turbo Trainer-40 (HTT-40) basic trainer aircraft (BTA).

The trainer, designed and developed by Hindustan Aeronautics Limited (HAL), will be built at facilities in Bangalore and Nashik.

The IAF will receive the first batch of two HTT-40 trainers within 20 months, followed by eight and then 20 aircraft annually. The aircraft will be procured at a cost of Rs 6,828 crore over a period of six years.

Rookie pilots of the IAF and the Navy will learn to fly on these aircraft in the first stage of their training. In the second and third stages, the pilots are trained on Kiran Mark II jet and Hawk advanced jet, respectively.

The HTT-40 deal is of great significance because the development of the aircraft, which began in 2013, progressed amid a see-saw battle between the HAL and the IAF over the future of the programme.

The HTT-40 Story

The HAL had proposed HTT-40 to replace the HPT-32 'Deepak' trainer, which the IAF had grounded in 2009 after a horrific crash that killed two experienced pilots.

Inducted in 1984, the HAL-designed aircraft faced persistent problems due to major flaws in its design. By 2010, at least 17 Deepak accidents had claimed the lives of 19 pilots.

However, in 2012, the Ministry of Defence (MoD) and the IAF rejected HAL's offer to develop the training aircraft, concluding that HTT-40 would prove costlier than 75 Swiss Pilatus PC-7 Mk II trainers for which a $1 billion deal was in sight by then.

In August of that year, Defence Minister AK Antony announced that the MoD had signed a Rs 2,900 crore deal for the Swiss aircraft, despite serious allegations about discrepancies.

But with 75 Swiss PC-7s forming only a part of the IAF's total requirement of 183 basic trainer aircraft, the HAL proposed that the IAF buy 108 HTT-40 trainers to complete the fleet.

The IAF, however, was in favour of buying additional PC-7s from Switzerland by exercising the option clause of procuring 37 more aircraft in the contract. The first few Swiss trainers from the original order had already been delivered by April 2013.

A shrill campaign against HAL's HTT-40 followed as the IAF consistently resisted the indigenous trainer over the next few years.

In July 2013, IAF chief Air Chief Marshal NAK Browne wrote to Defence Minister Antony insisting that 106 PC-7 trainers be imported from Switzerland. He argued that the HAL-built HTT-40 would be costlier "by over 89 per cent from 2018 onwards" compared to the Swiss PC-7.

If the MoD approved the proposal for additional PC-7s at this stage, the potential order for HTT-40 would have come down to 71 aircraft.

Around the same time, news reports said that the IAF had diluted at least 12 performance benchmarks, including some relating to pilot safety, to allow Swiss Pilatus PC-7 Mk IIs to qualify for procurement.

In 2014, the IAF floated a new Request for Information inviting Indian companies to submit bids to supply 106 PC-7 Mk II trainers in partnership with Pilatus. It was seen as an attempt to kill HAL's HTT-40 programme.

Earlier, sometime in 2013, it had approached HAL to build 106 of these Swiss training aircraft in the country under license from Pilatus. The proposal had been rejected by HAL, which continued to develop HTT-40.

HAL had argued that its trainer was not only cheaper but also easy to maintain and upgrade over its 30-year service life. However, after unsubstantiated allegations of corruption in the project mysteriously popped up in 2015, it agreed to build 106 PC-7 Mk II trainers in India.

But with focus on 'Make in India' under a new BJP-led government, the IAF was told in March 2015 that it would have to buy HTT-40 trainers being developed by HAL. The decision followed reports of the Swiss PC-7s being costlier than assessed while awarding Pilatus the contract.

A little over two years later, in June 2017, the aircraft made its inaugural flight in the presence of the then Defence Minister Manohar Parrikar.

"The young team [at HAL] has taken a calculated risk and they have flown the aircraft within one year and kept their assurance. The indigenous content on HTT-40 is close to 80 per cent. Almost 50 per cent of the components on HTT-40 are manufactured by private players of the Indian aerospace ecosystem," Parrikar had said then.

HTT-40 not only outperformed the Pilatus but also exceeded the IAF's performance criteria. While the IAF demanded a top speed of 400 km per hour, the HTT-40 has been tested to 420 km per hour.

Moreover, it has exceeded IAF's ceiling requirement of 20,000 feet by flying to 20,200 feet. It can take off and land in just 800 metres of runway, less than the 1,000 metres limit set by the IAF in the Preliminary Staff Qualitative Requirement.

But in 2019, when the HAL asked the IAF to issue a Request for Proposals for HTT-40, essential for the release of the money it needed to pay US's Honeywell Garret for the engine that will power the trainer, the IAF refused. It would issue an RFP only after the aircraft completed spin trials.

Trainer aircraft must be capable of entering and recovering from spin as it is necessary to familiarise trainee pilots to identify departure from controlled flight and the actions needed to recover from such situations.

Given the high risk involved in conducting this complex manoeuvre, the test progresses incrementally, turn by turn, and requires several flights.

HTT-40 cleared the "six-turn spin test" later that year.

"For HAL, clearing the HTT-40's six-turn spin tests removes a monkey from our backs," HAL's design chief, Arup Chatterjee, said back then.

Over the years, HAL resisted IAF's attempt to scrap the HTT-40 programme in favour of Swiss PC-7 trainers. It invested Rs 350 crore of its own money in the project.

The programme progressed without much support from the IAF and was finally rescued due to the Narendra Modi government's 'Make in India' push in the defence sector.

In August 2020, the government cleared the procurement of the aircraft, and the IAF finally issued an RFP for 75 HTT-40s in early 2021, along with a clause that included the option to acquire 38 more.