Hindustan Aeronautics Limited (HAL) has significantly revised its delivery targets for the indigenous HTT-40 basic trainer aircraft for the current financial year.
The state-owned aerospace major now expects to hand over only three aircraft to the Indian Air Force (IAF) by March 2026, a sharp reduction from the originally planned 12 units.
The delay is primarily attributed to persistent supply chain bottlenecks affecting the delivery of TPE331-12B turboprop engines from the US manufacturer Honeywell.
This development, reported on Friday, raises fresh concerns regarding the IAF’s pilot training schedule, which is already managing squadron shortages and the retirement of the older HPT-32 Deepak trainers.
The HTT-40 programme is a critical component of the government's 'Aatmanirbhar Bharat' (Self-Reliant India) initiative in the defence sector.
Contract and Original Timeline
In March 2023, the Ministry of Defence signed a contract worth ₹6,838 crore with HAL for the procurement of 70 HTT-40 aircraft.The delivery schedule was structured to provide 12 aircraft in the first year (commencing September 2025), eight in the second, and 20 annually thereafter to complete the order.
The aircraft boasts over 50 per cent indigenous content, with production lines established at HAL’s facilities in Bengaluru and Nashik.
However, the initial deadline of September 2025 for the first delivery has been missed due to the unavailability of new engines.
The Engine Supply Bottleneck
The core of the delay lies in the delivery of the Honeywell TPE331-12B engines, each rated at 1,100 shaft horsepower (shp). HAL had signed a $100 million contract with Honeywell in July 2022 for 88 such engines to power the fleet.While the first production engines were due in September 2025, revised estimates suggest the first unit will now arrive in January 2026.
HAL expects to receive four more engines by the end of March 2026, with supplies ramping up to two engines per month subsequently.
The remaining 56 engines are slated to be produced domestically by HAL under a technology transfer agreement.
Current Status and Operational Workarounds
Despite the engine shortage, HAL has maintained testing momentum by utilising refurbished "Category-B" (used) engines from prototype aircraft.- TH-4001: The first series production aircraft successfully completed its maiden flight from Bengaluru on 24 October 2025.
- TH-4002: The second production aircraft followed with its maiden flight from the Nashik facility on 6 December 2025.
Aircraft Capabilities
The HTT-40 (Hindustan Turbo Trainer-40) is a tandem-seat basic trainer developed by HAL’s Aircraft Research and Design Centre (ARDC). It is designed to fill the critical Stage-I training gap for rookie pilots.- Performance: The aircraft has a maximum speed of 420 km/h and a service ceiling of 20,200 feet.
- Endurance: It can fly for up to four hours, making it suitable for intensive training sorties.
- Versatility: The platform is optimised for operations across India’s diverse landscapes, ranging from sea-level bases to high-altitude Himalayan outposts.
Future Recovery Plan
HAL executives remain optimistic about recovering the lost timeline.The Nashik facility, commissioned specifically for this programme in 2025, is capable of producing 15 units annually to complement the output from Bengaluru. Once engine supplies stabilise, HAL plans to accelerate production to deliver over 20 aircraft per year post-FY26.
Simultaneously, the broader indigenisation effort continues, with weapon trials for the Tejas Mk-1A also on track for late December, signalling that while specific supply chain hurdles exist, the overall momentum of indigenous defence production remains forward-looking.
