HAL's Intermediate Jet Trainer displays ability to perform six turn spins on both sides

The Intermediate Jet Trainer (IJT) has successfully demonstrated the ability to perform six turn spins on both the left hand and right hand sides. The aircraft was designed and developed by Hindustan Aeronautics Limited (HAL) in Bengaluru for the stage II training of Indian Air Force pilots. Group Capt HV Thakur (Retd) and Group Capt A Menon (Retd) piloted the aircraft. According to a statement by HAL on Thursday, the IJT completed demonstrations of its capabilities in terms of altitude and speed envelope, load factor, satisfactory stall characteristics, and limited armament capability much earlier, as per news agency PTI.  

The statement said that IJT, which was brought as a replacement to the ageing Kirans of the Indian Air Force (IAF) fleet, also met all the requirements of the IAF during the demonstrations. The only thing that needed to be done was spin testing. The aircraft departed from controlled flight during the course of spin testing in 2016, bringing the programme to a temporary halt, as per the statement. A training aircraft's capacity to enter and recover from spin is essential to familiarise the trainee pilot with the signs of departure from controlled flight and the measures required to recover from such situations, it stated.

 HAL made considerable changes to the airframe after halting flight tests in 2016

As spin flight testing is essentially a high-risk manoeuvre, it is done turn by turn in stages. The motion of the aircraft in spin is unpredictable due to the intricate interplay of aerodynamic and inertia forces, and flight testing is the only way to determine whether or not its characteristics are acceptable. Following a temporary pause in flight tests in 2016, HAL made considerable changes to the airframe, such as relocating the vertical tail rearward and expanding the rudder area, and subsequently, flight testing began in April 2019. These changes included the installation of a new Anti-Spin Parachute System (ASPS), which is required for the aircraft's and test crew's safety during spin flight testing. 

IJT achieved a major milestone: HAL's Director (Engineering and R&D)

The new ASPS was installed on the plane in July 2020, and successful parachutist streaming was demonstrated in September 2020. In November 2020, HAL could begin stall and spin testing of the IJT in its new modified configuration. According to Arup Chatterjee, HAL's Director (Engineering and R&D), the IJT has achieved a major milestone by demonstrating its ability to have six turn spins on both sides. He also hoped that HAL will soon have state-of-the-art trainers for IAF pilot stage I and II training, with the completion of HTT-40 spin certification and development in IJT. Meanwhile, R Madhavan, Chairman and Managing Director, claimed that given the necessary resources and backing, HAL is capable of designing products to suit any requirement of the Indian Armed Forces. Notably, Wing Cdr M Patel (Retd) was the test director and Group Capt. KK Venugopal (Retd) was the safety pilot in command at telemetry.

With inputs from PTI

Image: Republic