Hindustan Aeronautics Limited (HAL)’s HTT-40 basic trainer aircraft program has encountered a schedule setback, with the first delivery to the Indian Air Force (IAF) postponed from September 2025 to January 2026. The delay stems from supply chain constraints tied to fresh engine deliveries from the US-based manufacturer Honeywell, which is providing the TPE331-12B engine that powers the trainer.

Key Details:

Original Delivery Date: September 2025.
New Delivery Date: January 2026.
Reason for Delay: Delays in new engine supplies from Honeywell.
Initial Solution: The maiden unit will fly with a reused prototype engine.
Engine Supply Timeline:
New engine deliveries are expected to begin in November 2025.
At least seven new engines are planned to be delivered by March 2026.
Production Target: HAL still aims to deliver 12 aircraft for the 2025–26 fiscal year.
Dependency: The achievement of this target relies on Honeywell adhering to the revised engine delivery timeline.

To keep the program moving, HAL will deliver the first aircraft to the IAF using a reused prototype engine already proven under flight-testing regimes. This interim measure ensures that aircraft handover begins on the revised timeline, even though the intended batch of new production-standard engines is still awaited.

Honeywell has committed to starting engine deliveries in November 2025. The company has indicated that at least seven units will reach HAL facilities by March 2026, allowing a ramp-up of production to meet IAF requirements. However, adherence to this revised supply schedule is critical in preventing follow-on slippages.

HAL’s production target remains ambitious, as the company intends to deliver 12 HTT-40 aircraft within the 2025–26 fiscal year despite the disrupted supply line. This necessitates careful coordination of engine integration, flight certification, and delivery schedules as soon as the new engines arrive.

The dependency on Honeywell’s timely dispatch of engines now forms the linchpin of HAL’s planning. Any further slippage in engine supplies would threaten the overall delivery commitment for FY 2025–26 and impact pilot training induction timelines for the IAF. HAL remains positioned to fulfil the commitment provided that supply stabilisation begins as per the revised November timeline.

IDN (With Agency Inputs)