HAL kicks off crucial testing of jet trainer that may have missed IAF bus
The spin flight testing of the much-delayed jet trainer is being seen as a developmental milestone even though there is no indication from the IAF about a possible order.
State-owned plane maker Hindustan Aeronautics Limited (HAL) on Monday announced that it has kicked off a crucial developmental test of a jet trainer that was planned as a replacement for the Indian Air Force’s ageing Kiran aircraft fleet.
The spin flight testing of the much-delayed Sitara intermediate jet trainer (IJT) --- or the HJT-36 single-engine aircraft --- is being seen as a developmental milestone even though there is no indication from the IAF about a possible order. The IJT project is running late by several years.
“The spin testing of an aircraft is the most crucial phase of its flight testing. The testing will be gradually progressed to assess the behaviour of the aircraft till six turn spins to either side to meet the targeted requirement,” the HAL said in a statement. HAL test pilots Group Captain HV Thakur (retd) and Wing Commander P Avasti (retd) conducted the tests on Monday.
Spin is a manoeuvre an aircraft gets into on its own when its controls are mishandled. Spin testing seeks to prove that the IJT can do a spin and recover safely from it, experts said. During the first flight test, the aircraft was taken through one turn spin to the left and right to test the spin characteristics, HAL said.
Rookie pilots in IAF go through a three-stage training involving the Pilatus PC-7 MkII planes, Kiran trainers and finally the Hawk advanced jet trainers before they can fly fighter jets. As the Kirans are approaching the end of their service life, some amount of stage-2 training is already being done on the PC-7.
Experts doubted if the IAF would order the IJT as it was a case of “too little, too late.”
The delay in the IJT programme, conceived more than two decades ago, has upset the IAF’s calculations, officials said. The project was sanctioned in July 1999 with a grant of Rs 180 crore. The IJT, first powered by a French engine and now a Russian one, was expected to get initial operational clearance by 2006 with deliveries to the IAF planned a year later.
HAL said the IJT has been redesigned for the spin test “by moving the vertical tail aft and extending the rudder surface.” “These changes (made) for ensuring satisfactory spin behaviour required extensive redesign of the rear fuselage and the rudder. The changes have been incorporated in two aircraft with the involvement and clearance from certification agencies at every stage,” the statement said.
After being modified, the two aircraft underwent significant flight tests to assess the general handling with the new configuration of fin and rudder, and the jets have been incorporated with the necessary safety devices (anti-spin parachute systems), it said.
Meanwhile, the IAF plans to buy the basic trainer aircraft from HAL to train rookie pilots. The defence ministry, in August, gave its go-ahead to the purchase of 106 Hindustan Turbo Trainer-40 (HTT-40) aircraft from HAL to provide a push to the government’s Atmanirbhar Bharat Abhiyan’ (self-reliant India movement).