Bengaluru / New Delhi: The TPE331-12 family of engines from Honeywell will power the Basic Trainer Aircraft (HTT-40) for the Indian Air Force (IAF) being built indigenously by state-owned Hindustan Aeronautics Limited (HAL).
Honeywell and HAL have firmed up a contract worth more than US $ 100 million for HTT-40 Engines. The contract was exchanged by Eric Walters, Sr Director OE Sales, Honeywell and B Krishna Kumar, Executive Director (E & IMGT) in the presence of R Madhavan, CMD, HAL,) in Bengaluru. The contract is for supply and manufacture of 88 TPE331-12B engines/kits along with maintenance and support services to power the basic trainers which are being built for the Indian Air Force (IAF).
According to CMD, HAL, “To address the training requirements of the IAF, HAL has successfully developed Basic Trainer Aircraft (HTT-40). And there is a potential requirement of 70 aircraft.” The talks and the contract for 70 Basic Trainers for the IAF are at an advanced stage.
Eric Walters, Senior Director OE Sales, Honeywell Defense & Space talking about the TPE331-12 family of engines said, “It has proven itself in operations all over the world. To meet the requirements of the IAF, we have committed to support and deliver engines as well as kits within the stipulated schedule.”
“In the coming years, Honeywell is committed to support export of HTT-40 aircraft along with other engine programmes which are currently on radar,” he said.
The TPE331-12B engine is a single shaft turboprop engine with integral inlet and gearbox. It has a two stage centrifugal compressor, power turbine, and gearbox. For outstanding operational characteristics, three stage axial turbine and turbine exhaust diffuser; EEC for reliable power.
According to an official statement from HAL, the Basic Trainers are powered by TPE331-12B engines and have been serving well since 2014. And both companies are exploring other areas including Repair & Overhaul of TPE 331-10GP / 12JR engines for variants of Dornier and 1 MW Turbo Generators, manufacturing. The ‘Manufacturing & Repair License agreement for Honeywell TPE331-12B Turboprop engine’ is a major milestone in the execution of 70 HTT-40 aircraft contracts with IAF.
In 2021, HAL had received a Request for Proposal (RFP) from the IAF for basic trainer HTT-40. And once the contract is finalised, the trainer will have more than 60 percent indigenous content and is supported by agencies such as Aircraft and Systems Testing Establishment (ASTE), Centre for Military Airworthiness and Certification (CEMILAC), and Regional Director Aeronautical Quality Assurance (RDAQA). Initially some of the 70 trainers will be built in Bengaluru where it has been designed and then it will be moved to Nasik for series production. The HAL is hoping to get an order for 106 trainers from IAF.
Indigenously built trainers will be used not only for basic flight training but also for aerobatics, instrument flying and close formation flights. And its secondary roles would include night flying and navigation.




