Honeywell Delays TPE331-12B Engine Supply for HAL's HTT-40 Trainer Aircraft

Hindustan Aeronautics Limited (HAL) is facing a setback in its efforts to deliver the HTT-40 basic trainer aircraft to the Indian Air Force (IAF) due to delays in the supply of Honeywell's TPE331-12B turboprop engines. Originally scheduled for delivery in September 2025, the first engine is now expected in November 2025, with subsequent deliveries to follow in early 2026. This delay has prompted HAL to use a 'Category B' (used) engine from one of the prototypes for the maiden flight of the series production aircraft, planned for late September 2025.

The TPE331-12B engine, renowned for its reliability and efficiency, is a critical component for the HTT-40 trainer. Under a $100 million contract signed in July 2022, Honeywell is to supply 88 engines and kits to HAL, with 32 units to be delivered by Honeywell and the remaining 56 to be manufactured by HAL through technology transfer. The delay in engine deliveries has raised concerns about HAL's ability to meet its contractual obligations to the IAF.

HAL has urged Honeywell to expedite the delivery schedule to ensure that the first batch of 12 HTT-40 aircraft can be supplied to the IAF within the current financial year. Production is underway at HAL's facilities in Nashik and Bengaluru, with 10 units from Nashik and 2 from Bengaluru expected in the initial batch. The HTT-40 is designed to replace the aging fleet of HPT-32 trainers and is integral to the IAF's pilot training program.

The delay in engine supply underscores the challenges faced by defense manufacturing programs, where supply chain issues can significantly impact timelines and operational readiness. HAL continues to work closely with Honeywell to resolve the delays and meet the training needs of the IAF.