Delay in the intermediate jet trainer (IJT) programme and its impact on training have been questioned by parliamentarians. IJT slippage immediately means extension of life for the Kiran fleet which should have been retired by now. But to maintain the Kiran fleet is a herculean task in itself.

Rendering Yeoman Service

The Kiran aircraft has been a workhorse of the Indian Air Force (IAF) since 1968. It was the basic jet trainer used for intermediate stage of training after the initial training on HT-2 and later on HPT-32 aircraft. Powered by the Rolls-Royce Viper Mk-II engine, it was designated Kiran Mk-I. Later, under production aircraft were fitted with under-wing hard points for weapon training and was designated as Kiran-IA. A total of 190 Mk-I and 1A aircraft were built. A version was also powered by the more powerful Bristol Siddeley Orpheus engine, named Kiran Mk-II, 61 of which were inducted into the IAF in the beginning of 1985. Based on the British Jet Provost design, the Kiran fleet has seen the IAF through 44 years of training. Practically, every pilot serving in the IAF today has had the pleasurable experience of flying this excellent machine.

Kiran aircraft became the darling of the country when in 1996 the nine-aircraft Surya Kiran Aerobatic Team (SKAT) was shaped as the ‘Ambassadors of the IAF’. Their world-class breathtaking display could give goose pimples to any patriotic watcher. The Kiran fleet is now becoming difficult to sustain. Spares are difficult to get and the fleet is getting stretched. The SKAT has been disbanded and is to be replaced by the BAE Hawk. More recently, ace badminton player and London Olympics bronze medallist Sania Nehwal flew a Kiran Mk-II aircraft at the Air Force Academy at Dundigal, near Hyderabad.

Sitara–The New Jet Trainer

The IAF had visualised the replacement of Kiran fleet well in time. In 1997, HAL began design work on an intermediate jet trainer (IJT), designated HJT-36. Government approval for the project was received in June 1999 and the value of the contract was then estimated at Rs. 180 crore. Two prototypes were manufactured, the first, PT-1, flew on March 7, 2003, and was christened as the “Sitara”; and the second prototype (PT-2) flew on March 26, 2004. The writer was then the Commandant of ASTE Bengaluru. At the very initial stage, the IAF assessed the Snecma Turbomeca Larzac engine delivering 14.1 kN thrust, as under-powered. In August 2005, HAL in response, reached a deal to replace the Larzac engine with the NPO Saturn AL-55I with 16.9 kN thrust. The deal also provided for licence-production of the engine in India by HAL. The IJT project cost was now revised to Rs. 467 crore. The date for initial operational clearance (IOC) scheduled for March 2004, was revised to March 2007 and final operational clearance (FOC) was rescheduled for March 2008. Contract for 12 limited series production (LSP) aircraft was signed in March 2006 at a total cost of Rs. 486.82 crore. Deliveries were to be completed by March 2010.

The IJT project suffered a setback owing to inordinate delay in the delivery of the NPO Saturn AL-55I engine. The first AL-55I engine was received from Russia on December 28, 2008, two years later than committed. Flight tests on the PT-1 powered by the new engine commenced in May 2009.

Following further development and extensive testing, the IAF placed an order with HAL for 73 aircraft. After 280 test flights, the aircraft entered LSP in 2009 for the first 12 aircraft to be delivered to the IAF. The first LSP aircraft began its flight test phase in January 2010 and the IOC was expected by July 2011. The IAF order was expected to grow in the years to come. However, till date, not a single LSP aircraft has actually been delivered to the IAF. LSP 1 and 2 are being utilised for flight testing. LSP 3 and 4 are also planned to be utilised for flight testing to expedite IOC. In February 2007, at the Aero India air show at Yelahanka, PT-1 suffered serious damages when its canopy opened up during takeoff, causing the aircraft to veer off the runway. On February 4, 2009, PT-2 landed on its belly after a routine aerobatic sortie, resulting in extensive damage to the undercarriage and one of the wing tips. Failure of the structural testing specimen in 2010 and an accident on PT-1, involving an ejection on April 28, 2011, the aircraft was grounded till the completion of investigations. The aircraft was cleared to resume flight testing only in February 2012 after redesign of the primary control circuits in all three channels. These events led to further delay in the programme.

Dogged by Uncertainty

Apart from the order for 12 LSP aircraft, on March 22, 2010, the IAF had concluded a contract for another 73 IJT aircraft with AL-55I engine, taking the total order to 85. The value of the order for 73 IJT aircraft with associated spares and equipment was around Rs. 6,200 crore. Current estimates are that the aircraft ordered will be delivered between March 2013 and March 2017. However, significant part of the testing is yet to be completed—refinement of stall characteristics and thereafter spin trials—both of which are essential for a basic training aircraft. Envelope expansion to 7g and night flying are other important segments of the flight test profile yet to be completed. The AL-55I engine still has issues related to weight reduction (around 30 kg) and engine life extension that need resolution. Also the installed engine thrust is currently lower than required, which would degrade the performance by up to 20 per cent. Will it then end up at same performance level as the Pilatus PC-7 Mk II? IOC is now likely to be obtained by December 2013.

In an interview with an online defence magazine of international repute, Chief of the Air Staff Air Chief Marshal N.A.K. Browne is quoted to have said, “We are concerned as we are not seeing significant progress on the IJT. HAL put in a dedicated design team, yet there are no results. This is a training aircraft and we cannot compromise on safety.” He also indicated in the interview that issues that continue to dog the IJT programme include: controls, engines and the aircraft’s weight, stall and spin characteristics. The IAF has stationed its own personnel at HAL to monitor the development of the IJT. A consultancy with BAE Systems is also in the process of being signed. There were rumours that the programme was on the verge of being scrapped on account of the inability of HAL to deliver performance. But the report was quickly denied by the IAF and HAL. However, the IAF now needs to plan for real situations.