Govt had sanctioned Rs 180 crore for project in 1999. Improper engine selection had a cascading effect on design and development process of aircraft, says auditor

New Delhi: The Intermediate Jet Trainer (IJT) has suffered delays due to incorrect selection of engine and delayed resolution of the ‘stall and spin’ function of the aircraft, the Comptroller and Auditor General (CAG) has said.

IJT is an indigenously designed and developed aircraft by Hindustan Aeronautics Limited (HAL) to replace the ageing fleet of the Kiran jet trainer aircraft in service with the Indian Air Force (IAF) the Stage-II training of pilots. Stall and spin refer to the aerodynamic nature of the aircraft.

“The incorrect assessment of the required thrust and lack of clarity on Type A engines led to improper engine selection which in turn had a cascading effect on the Design and Development (D&D) process,” the CAG report tabled in Parliament on 10 August stated.

It added that although stall tests were initiated quite early in the IJT program, a lack of clarity on resolution of stall and spin issues and improper planning in the initial stages of the development process led to a delay of more than 20 years in the project.

The state owned HAL had initially identified one type of engine for the design and development phase and procured a French engine on loan basis, which was then returned to the Original Equipment Manufacturer (OEM) in June 2010.

The HAL placed an order for the second engine, AL-55i, from Russia in July 2005, and it was received in January 2009.

The national auditor stated that the integration of the second engine — which was a higher thrust engine after the build-up of the prototype — necessitated modifications as the aircraft failed to demonstrate the stall and spin characteristics.

The Ministry of Defence had sanctioned Rs 180 crore for the indigenous design and development of the project in 1999.

In its report, the national auditor flagged that HAL failed to deliver the aircraft to the IAF, despite having incurred an expenditure of Rs 710.08 crore as of March 2022.

The report concluded that the HAL should have anticipated the impact of integrating a new engine at a later stage and taken timely measures to resolve issues pertaining to spin and stall characteristics.

Last year, the IJT had successfully demonstrated the capability to carry out six-turn spins to the left hand and right hand sides.

According to HAL, the IJT incorporates the simplicity necessary for ease of conversion from Basic Piston Trainer and the sophistication required for quick conversion to the complexities of an Advanced Jet Trainer. Apart from pilot training, the aircraft can be used for general flying, navigation formation flying, instrument and cloud flying, basic air to ground and air to air weapon aiming, tactical and night flying.