IJT taxies back after a flying demonstration at Aero India 2011. Photo Copyright© Vijainder K Thakur
The IJT program was sanctioned by the government in 1999 with an initial budget of Rs.180 crore as a replacement for the HJT-16 Kiran.
The aircraft has been developed by Aircraft Research & Design Center, a division of HAL.
Max Speed: 750 kph
Max Mach No: 0.75
Max G: +7.0/-2.5
Max Altitude: 9 km
Max T/O Weight: 5.4 tons
Normal Training Weight: 4.25 tons
Max Weapon Load: 1 ton, 5 hard points
Powerplant: NPO Saturn's AL-55I (I for Indian)
Wing Span: 10m
The aircraft features a glass cockpit with a Head Up Display. HAL has developed a simulator for the aircraft in partnership with Elbit of Israel.
AL-55I was developed specifically to power the HJT-36 and has a thrust of thrust of 1,700 with provision for after burning to get a max thrust of 3,500 kgf. The engine is also designed to support thrust vector control.
NPO Saturn AL-55I Turbojet
The engine has a two-shaft design with a three-stage axial low-pressure compressor, five stage high pressure compressor, annular combustor, single stage cooled high and low pressure turbines and non-variable-area jet nozzle common to both loops.
Initial production of the engine is being handled by NPO Saturn JSC and UMPO JSC. HAL will later license produce the engine locally.
Bench tests of the AL-55I begai in March 2006 and flying tests on board the MiG-AT flying testbed in July 2008.
Maiden flight of the AL-55I powered HJT-36 took place on May 9, 2009.
Thrust and the limiting point, kgf 1,760
Specific fuel rate at the limiting point, kg/kgf.h 0.69
Specific fuel rate in cruising mode, kg/kgf.h 0.645
Air use, kg/с 28.5
Gas temperature before the turbine, Tc 1,445
Length, mm 1,210
Entry diameter, mm 590
Dry weight, kg 315
In March 2013, Minister of State for Defense Jitendra Singh told Lok Sabha in a written reply that "certification of IJT was also delayed due to an accident of Prototype-1 and failure of Stress Test Specimen." [via PIB]
In October 2012, Air Chief Marshal NAK Browne told AIN that he was worried about the delay in the AJT project.
"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 said.
There are outstanding issues with the aircraft's controls, engines, weight, stall and spin characteristics.
HAL design director T. Suvaranaraju, confirmed to AIN that the project is facing problems.
"We have had a setback…four aircraft are in flight mode. We will recover the lost time," he said.
HAL began designing of the IJT in 1997. The first prototype flew in March 2003.
Two accidents, one during Aero India 2005 and the other during Aero India 2007 set back the program.
Also,there was a delay on account of a decisiontswitch from the French to the Russian engine.
Four prototypes of the aircraft are currently flying - PT2, LSP1, LSP2, LSP3.
PT1 crashed in April 2011. It was powered by a French engine. Subsequent prototypes are powered by NPO Saturn's AL-55I engine.
The first AL-55I engine was delivered to India in November 2007. Its larger size mandated changes to the airframe.
In March, 2013 HAL Chairman Dr R K Tyagi told Express, "HAL is making all out efforts to achieve the Initial Operational Clearance (IOC) as early as possible. The project is being closely monitored to ensure that any support or decisions required are given on a fast track mode."
The aircraft had flown more than 600 flights as in March 2013. HAL expects to get IOC during the later half of 2013.
IOC was earlier expected by the end of 2011.
During Aero India 2011, HAL officials had indicated that the IJT will receive Initial Operational Clearance (IOC) by July 2011, after completion of spin trials on the aircraft.
Elaborating on the reasons for IOC being pushed back, M R K Raju, head, Regional Centre for Military Aviation (RCMA), Pashan, a lab under DRDO, told the press on Wednesday, March 30, 2011:
“We plan to stick to the certification process followed in the case of LCA Tejas. The IOC for the IJT should come by year end.
The IJT completed hot weather trials (HWTs) in Jaisalmer in early 2011.
“It was the first HWTs with the AL-55I Russian engine, while similar trials were held in Nagpur in 2006 with the Snecma Larzac,” a source told AW&ST. “The platform had met all the technical and system performance specifications during HWTs. The environmental system air-conditioning inside the cockpit, environmental control systems, and factors for pilot comforts were checked.”
The IAF is currently (February 2011) not satisfied with the aircraft's spin characteristics. The aircraft is being fitted with an anti-spin parachute system (ASPS)
Both the prototypes suffered minor crashes. In February 2007 PT1 suffered damage after its canopy flew off during take-off from Yelahanka. The aircraft veered to its right, burst a tyre, damaged both its wings. The pilot escaped unhurt.
In February 2009 PT2 landed on its belly during a routine sortie. The aircraft suffered structural damage to its undercarriage and a wing.
An IJT with two pilots crashed on April 28, 2011 in Tamil Nadu. The pilots ejected safely.
It is envisaged, 225 IJTs will be produced for use by the IAF, IN, as well as the Air Force's Surya Kiran aerobatic team.
HAL has received firm orders for 12 Limited Series Production (LSP) and 73 production aircraft.
HAL has confirmed the delivery of aircraft in a phased manner after grant of Initial Operational Clearance.
As in March 2013, the IJT is targeted to be inducted in the IAF from 2014 onwards.
As per the original schedule, the first batch of IJTs was to have been delivered to the Air Force in 2005-06.
The revised schedule is for the Air Force to receive the 12 LSPs by 2011.