The HTT-40 is currently undergoing a string of elaborate tests at HAL to demonstrate that it is safe for rookie pilots and meets IAF’s exacting standards for trainer planes. Test pilots have wrapped up intensive flight tests but some brutal trials are yet to be conducted, said a second official

The Indian Air Force (IAF) plans to start the official process within three months for the possible purchase of 70 locally produced basic trainers from state-owned aircraft maker Hindustan Aeronautics Limited (HAL), three senior IAF officers said on condition of anonymity.

IAF is set to send a request for proposal (RFP) to HAL for the indigenous Hindustan Turbo Trainer-40 (HTT-40) before the end of the year, they added.

“The HTT-40 has entered the final stages of rigorous testing. The air force is optimistic that the trainer will meet its requirements. If all goes well, the RFP will be out by the year-end,” said one of the officials cited above who asked not to be named.

The HTT-40 is currently undergoing a string of elaborate tests at HAL to demonstrate that it is safe for rookie pilots and meets IAF’s exacting standards for trainer planes. Test pilots have wrapped up intensive flight tests but some brutal trials are yet to be conducted, said a second official.

A few days ago, the aircraft successfully completed the six-turn spin (towards the right), recovering from an uncontrolled flight using conventional methods. “The next stage of trials will be critical as it involves testing the HTT-40’s spin behaviour in the left direction, which is far more complicated,” the second official said.

If the remaining tests go smoothly, HAL could begin production by early 2021, said a third official tracking the air force’s modernisation drive. IAF, however, is clear that it does not want a piecemeal delivery of the basic trainers. “We don’t want HAL to deliver the aircraft in ones and twos as that will not meet our training requirements. We would need at least 20 planes to begin training. According to our estimates, it will take HAL around four years to deliver that number,” the third official added.

To facilitate the release of the RFP this year, IAF plans to seek a fresh Acceptance of Necessity (AoN) from the defence acquisition council to pursue the HTT-40 purchase under the Defence Procurement Procedure (DPP) 2016 instead of DPP-2008, which currently covers it. “That’s important because under DPP-2008, user trials have to be conducted before the RFP is issued. However, the provisions of DPP-2016 allow the RFP to come before the user trials,” said the second official cited above.

The upcoming RFP may also allow HAL to release around $25 million to upgrade the Honeywell TPE331-12B turboprop engine that powers the basic trainer to extract maximum performance from the aircraft, said the first official. HAL was reluctant to spend on the upgrade unless the order came through.

Rookie pilots in IAF go through a three-stage training involving the Pilatus PC-7 MkII planes, Kiran trainers and finally the Hawk advanced jet trainers before they can fly fighter jets. As the Kirans are approaching the end of their service life, some amount of Stage 2 training is being done on the PC-7.

The defence ministry in July suspended business dealings with Pilatus Aircraft Limited for one year for violation of a pre-contract integrity pact in a ~2,900-crore contract for 75 basic trainers, and also factoring in ongoing Indian investigations against the Swiss plane maker for alleged corruption and irregularities.

The contract included a follow-on purchase of 38 more planes, but the ban means IAF can’t invoke the clause. The order for additional planes could be sourced from HAL, said a fourth IAF official. Experts welcomed IAF’s decision to take the HTT-40 purchase forward. “It’s a big thumps up to indigenisation and the RFP is an indicator that the locally made trainer will meet IAF’s requirements. It is now up to HAL to meet the timelines and provide adequate technical support. It has been found wanting in some of those aspects in the past,” said Air Vice Marshal Manmohan Bahadur (Retd), additional director general, Centre for Air Power Studies.