India, Sept. 21 -- Aircraft maker Hindustan Aeronautics Limited (HAL) may have delivered the first batch of HTT-40 basic trainers to the Indian Air Force (IAF), out of 70 on order, but a steady supply of engines by US firm Honeywell remains critical to keeping the Rs.6,838-crore programme on schedule, officials aware of the matter said.

The aerospace major hopes Honeywell will resolve supply-chain bottlenecks and stabilise TPE331-12B engine deliveries from next year, the officials said.

The IAF ordered 70 basic trainers three years ago to train its rookie pilots. Under the contract, HAL was to deliver 12 trainers to the IAF in fiscal 2025-26 but failed to deliver any aircraft due to an engine shortage. Honeywell, which faced supply chai...