Like the Japanese, the French are consummate business entities, Dassault dumped the HAL joint venture partnership knowing well the clear fault lines that existed via their legacy association with the defence public sector unit

The Parliament’s Public Accounts Committee (PAC), which is an audit watchdog consisting of MPs, released a report on 14 December, 2018 lambasting government-owned defence manufacturer Hindustan Aeronautics Ltd (HAL), among other entities, for its lacklustre performance in delivering units of the Light Combat Aircraft (LCA) Tejas to the Indian Air Force.

The report points out the PAC’s dim view of HAL’s performance, stating, “The ADA/HAL have also not been able to provide IAF with even a single production standard trainer aircraft till date. Further, since HAL could not augment its capacity in line with the demand of the IAF, the IAF will have to depend on imported aircraft for a longer time, given its dwindling squadron strength.”


The Hindustan Aeronautics Limited the largest defence public sector undertaking (DPSU) under the Ministry of Defence (MoD), is also the premier aeronautical complex in South East Asia, but with a dubious record and some credits. It had proposed the development of a replacement to its HJT-16 Kiran trainer aircraft for the intermediate training stage (Stage 2) of the trainee pilots of the Indian Air Force (IAF). In 1997, HAL on its own initiative commenced designing an intermediate jet trainer (IJT). The MoD accorded approval in 1999, after the IAF had reviewed the project details.

Two prototypes were cleared with an initial budget of `180 crore which was subsequently increased to `465 crore in 2005. The expenditure so far is `635 crore. The IAF has been committed to the project from its inception and has even placed an order for 73 aircraft. It has also promised to provide additional funds to the program.

Plagued With Problems

The Larzac engines from France powered the first two prototypes of the HJT-36 Sitara. However, the IAF felt the aircraft was under powered as the engine developed only 14.1 kN thrust. It is standard practice that an engine is decided during the initial design phase itself, when the designers, giving margin for some additions, estimate the all-up weight. It is also accepted that the final weight of an aircraft will be slightly higher than the earlier estimates. In the case of the HJT-36, however, the final weight was much higher than the earlier approximation, leading HAL to turn to Russia for another engine with a higher thrust rating. The NPO Saturn AL-55I engine, which produces 16.9 kN thrust, was selected and a contract signed for an initial production of 250 engines, with the option for more. The agreement also included assistance in setting up production in HAL’s Koraput Engine Centre. The first of the engines was delayed by two years, the first of the many delays to follow and was delivered only in December 2008. Fitted with the new engine, the PT-1 flew on May 9, 2009.

NPO Saturn AL-55I Engine

Although the new engine performed well on the aircraft, it has problems. First, the engine is yet to be certified; second, it is reported that this engine has a very short ‘flight-life’. It requires an overhaul at every 150 hours of flying, when ideally it should be around four times this figure and with a total life of about 1,800 to 2,400 hours. Considering the intensity of flying that the aircraft would be subjected to in training, the short lifespan translates to an overhaul every two months or so, which further translates to extended down time for every aircraft, at a colossal utilisation of man-hours. 

This would inflict extra pressure on the maintenance staff and engine production factories and would require an increased buffer stock of engines. As per the manufacturer, subsequent to flying a certain number of hours, the engine life may be increased. The change, however, in the overhaul schedule can be incorporated only after a strip examination of each component and exhaustive ground testing. The Russians are confident that the requirement of 600 hours between overhauls and a total lifespan of 1,800 hours can be achieved as the IAF gains experience on the maintenance of the engine. One can be optimistic, but should not take it at face value.

Design Flaws

Any trainer aircraft has to have safe stalling and spinning characteristics. This is essential as inexperienced trainee pilots could get into a difficult situation due to mishandling of controls. Even inexperienced pilots should have the confidence to effect a safe recovery from a stall or spin. As per reports, stall tests were aborted on the HJT-36, as the aircraft was rolling 16 degrees at the point of stall. This was a very undesirable characteristic and had to be rectified on priority.

On July 5, 2014, Shiv Aroor, a defence correspondent, had filed an exclusive report (Livefist, “Exclusive: Totally Cornered, HAL to Redesign Lumbering Intermediate Trainer”): “The HJT-36 aircraft presently weighs around 4,150 kg in its normal training configuration….HAL is envisaging achieving maximum possible weight reduction/optimisation for the aircraft….The design of the above need to be revisited, analysed and the scope for weight reduction/optimisation studied while ensuring the required strength, stiffness and fatigue criteria….Towards this HAL is looking forward for partnership/technical assistance/consultancy from a well experienced airframe design house….This weight reduction/optimisation study must be comprehensive, encompassing all the Structure, Mechanical Systems and Electrical Avionics Systems.”, was reported.

The then Defence Minister, Arun Jaitley (not by mere coincidence), made it official on August 5, 2014, in response to a question said: “HAL, which has been developing the IJT to replace the Kiran aircraft, has not so far been able to resolve critical wing and airframe design and development issues related to stall and spin."

On account of the inordinate delay in the IJT project, the IAF initiated the process for extending the technical life of the Kiran aircraft. The IAF has also initiated action to look for alternative options for the IJT.” 

Ending Note

Training is an important phase in a pilot’s life. The basic and advanced training in the IAF has been taken care of with the induction of the Pilatus PC-7 and the Hawk respectively. Hopefully, the Raksha Mantri would appreciate the predicament of the IAF and fast-track the procurement of an IJT from abroad as an interim solution, since there is no word on the aircraft in the public domain. One also hopes that the IJT Sitara does not go the LCA way and is indefinitely delayed.

IDN wishes to thank Air Marshal Dhiraj Kukreja (Retd) for this excellent piece