Bengaluru, Sept. 15 -- India's basic trainer aircraft programme, crucial for training rookie pilots, is on the verge of a milestone as aircraft maker Hindustan Aeronautics Limited (HAL) is preparing to conduct the maiden flight of the country's first series production Hindustan Turbo Trainer-40 (HTT-40) plane and racing to meet a longstanding need of the air force, officials aware of the matter said on Sunday. The first flight of the mass production aircraft will take place in two weeks, the development coming after two HTT-40 prototypes were flight-tested for more than 900 hours over nine years before HAL reached series production of the platform that will serve as a stepping stone for pilots to develop critical flying skills, the officials said, asking not to be named. HAL hopes to deliver the first HTT-40, powered by Honeywell's TPE331-12B turboprop engine, to the Indian Air Force (IAF) in January 2026 and 11 more before the financial year ends under a Rs.6,838-crore contract signed two years ago with the government for 70 locally made basic trainer aircraft. "The first flight of the series production aircraft is planned for September-end. It will fly with a 'Category B' (used) engine that powered one of the prototypes as the supply of engines by Honeywell is a bit delayed. The firm, like many others, is wrestling with supply chain bottlenecks," one of the officials said. Honeywell was supposed to deliver the first engine in September under a $100-million contract signed three years ago for the supply and manufacture of 88 TPE331-12B engines/kits to power the HTT-40s to boost the initial training of IAF pilots. The US firm will supply 32 units and the rest will be built by HAL through technology transfer. Honeywell has told HAL it will deliver the first engine in November and at least six more before March 31, 2026, with further deliveries at the rate of two units every month, said a second official. The state-run plane maker has asked the US firm to try and deliver more engines so that it can supply 12 basic trainers to IAF this financial year as required under 70-aircraft contract. The first HTT-40 was to be delivered to IAF in September. HAL can produce a total of 20 HTT-40s a year at its factories in Bengaluru and Nashik. The tandem seat HTT-40 has an air-conditioned cockpit, modern avionics, hot refuelling capability (refuelling with the engine running on the ground), and zero-zero ejection seats (for safe ejection at low speeds and low heights). The HTT-40 currently has a local content of 56%, which will progressively be increased to more than 60% through further indigenisation of major components and subsystems. Currently, ab initio (Stage-I) flying training of all rookie pilots is carried out on Swiss-origin Pilatus PC-7 MkII basic trainers. Stage-I training is common for all pilots after which trifurcation into fighter, transport and helicopter streams takes place. Those selected for the fighter stream proceed for Stage-II training on PC-7 MkII and Kiran Mk-1A jet trainers and then Stage-III on the British-origin Hawk advanced jet trainers before they can fly supersonic fighter planes. Pilots from the other two streams carry out their Stage II and III training on different types of transport aircraft and helicopters. Plans to buy more Pilatus PC-7 MkII trainers were hit in July 2019 after the defence ministry suspended dealings with Pilatus Aircraft Limited for one year for violation of a pre-contract integrity pact in a Rs.2,900-crore deal for 75 basic trainers, and also factoring in Indian investigations against the firm for alleged corruption and irregularities. The Pilatus contract included a clause for follow-on purchase of 38 more planes. The air force plans to retire the decades-old Kiran trainers as soon as it gets a replacement. The delayed Sitara intermediate jet trainer (IJT), being developed by HAL, was planned as a replacement for the IAF's Kiran fleet to carry out Stage-II training of fighter pilots but the project was hit by a raft of developmental setbacks. It was sanctioned in July 1999 with a grant of Rs.180 crore. The IJT, or Hindustan Jet Trainer-36, was rebranded as Yashas and unveiled in its new avatar with significant upgrades in February, with HAL now pitching it as a capable Stage-II trainer. A pivotal moment in the IJT's development came three years ago when the aircraft successfully demonstrated its capability to carry out six turn spins, a key requirement for trainers and the most crucial phase of flight testing. The capability to enter and recover from a spin is a necessity for a trainer aircraft to familiarise trainee pilots with departure from controlled flight and the actions required to recover from such situations....