| HTT-40 | |
|---|---|
 | |
| General information | |
| Type | Basic training aircraft |
| National origin | India |
| Manufacturer | Hindustan Aeronautics Limited |
| Designer | Aircraft Research and Design Centre[1] |
| Status | In production |
| Primary user | Indian Air Force |
| Number built | 2 prototypes |
| History | |
| Introduction date | 2025 (planned)[2] |
| First flight | 31 May 2016[3] |
| Developed from | HPT-32 Deepak |
TheHAL HTT-40 (Hindustan Turbo Trainer-40) is an Indiantraining aircraft designed and built byHindustan Aeronautics Limited (HAL). It will replace theIndian Air Force's retiredHPT-32 Deepak as a basic trainer.[4][5]
The HTT-40 is atandem seattrainer aircraft powered by a 1,100 hp (820 kW)turboprop engine. In early 2012, the company forecast building 106 examples.[5]
By the middle of 2012 the aircraft's future was in doubt as the Indian Air Force ordered 75Pilatus PC-7 Mk IIs to fill the role envisioned for the HTT-40. In September 2012, the Air Force indicated that it had formally rejected the HTT-40 for service based on its cost per aircraft being double that of the PC-7 Mk II, a proven aircraft, already in service worldwide. AnMoD official noted, "We would be willing to pay higher rates to build indigenous capability in strategic defence equipment. But can HAL argue that the capability to build basic trainers is strategically vital[?]"[6][7][8]
At that time HAL did not confirm the IAF announcement that it will not buy the HTT-40, nor did the company indicate whether the aircraft's development will be continued. A company spokesman said, "We treat all MOD issues/proposals as confidential... All our projects are conceived with national interest in mind though, at times, some of those take time to fructify".[6]
The project formally began in 2013 with an internal funding of₹350crore (equivalent to₹595 crore or US$70 million in 2023) from HAL. It took five years for the prototypes to enter spin testing phase.[9]
Once the HTT-40 started flying, the Indian Air Force commander publicly stated that IAF will buy the HTT-40 in large numbers.[10]
On 28 February 2015, it was reported that the MoD had selected 68 HAL HTT-40 trainers and 38Pilatus trainers to replace its current trainer fleet, stating that this move was "commercially viable".[11]
On 21 June 2015, HAL chose theHoneywellGarrett TPE331-12B turboprop to power the trainer.[12] The deal was signed on 27 July 2022, for 88 engines, kits, maintenance and support worth more than $100 million. Honeywell will work with HAL to extend support for exports.[13]
HAL rolled out the first prototype on 2 February 2016[14] and it first flew on 31 May 2016.[3]
The HTT-40 made its first public introduction flight on 17 June 2016, withDefence MinisterManohar Parrikar in attendance at the HAL airport in Bangalore.[15] On 19 May 2017, the second prototype had its first flight.[16]
In July 2019 it was anticipated that initial operational clearance would be reached by end of 2019 and that, after placement of an order, the first aircraft would be delivered to the IAF within a year.[17] An HTT-40 prototype demonstrated critical six-turn spin test capability in September and sought final operational clearance. The aircraft also cleared Air Staff Qualitative Requirements (ASQRs). HTT-40 procurement falls under the category of "Indian Designed, Developed and Manufactured” (IDDM), as per Defence Procurement Policy (2016).[9][18]
By August 2021, the HTT-40 had completed its spin certification flight testing.[19] The platform received its provisionalcertificate of airworthiness from theCentre for Military Airworthiness and Certification (CEMILAC) on 6 June 2022.[20]
In January 2020, HAL announced that limited series production is to start in year 2020–21.[21] On 11 August 2020, the Defence Acquisition Council approved procuring 106 HTT-40s for the Indian Air Force.[22] AtAero India 2021, HAL receivedrequest for proposal from the IAF for 70 HTT40s with an option for 38 more. Production will take place at the Bangalore and Nashik manufacturing plants.[23][24]
At DefExpo 2022, IAF and HAL concluded₹6,800crore (equivalent to₹72 billion or US$850 million in 2023) crore contract for 70 HTT-40. The remaining 36 will be procured after operationalization of HTT-40, with a possible follow on of 38 more units.[25] On 28 July 2022, HAL signed a $100 million deal withHoneywell Aerospace for the supply of 88TPE331-12B engines with support kits for the programme. While 32 would be delivered directly by the firm, the rest would be manufactured by HAL in India under atransfer of technology agreement.[26] A Manufacturing and Repair license agreement was also signed.[27][28]
On 6 March 2023, an agreement was signed to supply the IAF with HTT-40 aircraft and related equipment. The aircraft delivery will begin in September 2025 and be completed by March 2029.[29] A total of 12 HTT-40 are to be delivered in the year, including 10 from Nashik and 2 from Bangalore production line. This would be followed by 20 aircraft per year including 15 and 5 aircraft from Nashik and Bangalore production line, respectively.[30]
One of the prototype of the aircraft participated in the inauguralflypast at theAero India 2025 event.[31] As of 14 September, HAL was preparing for the maiden flight of a serial production HTT-40 aircraft within two weeks. The flight would be conducted using a Category B engine which was used by one of the prototypes since Honeywell has not commenced engine deliveries due tosupply chain issues. The first engine is to be delivered in November, followed by six more engines by end offiscal year, at a rate of two units per month though HAL has asked them to try and supply more engines. Meanwhile, HAL plans to deliver the first aircraft by January 2026 with another 11 to be delivered by March 2026. The aircraft will have an initial indigenous content of 56% which will be enhanced to over 60% later.[26]
The second production line of HTT-40 along with the third production line ofTejas Mk1A at HAL's Nashik facility was inaugurated by theDefence Minister,Rajnath Singh on 17 October. The preceding production lines of both aircraft is based in Bengaluru. A flying formation of Tejas,Su-30MKI and HTT-40 was exhibited on the occasion.[32][33][34]
The maiden flight of the first serial production HTT-40 aircraft wth tail numberTH-4001 was successfully conducted on 24 October 2025 fromHAL Airport inBengaluru.[35][36]
Data fromJane's All the World's Aircraft[39]
General characteristics
Performance
Armament
Aircraft of comparable role, configuration, and era
Media related toHAL HTT-40 at Wikimedia Commons
