Indian Defence Review

By placing an order for 123 LCA Tejas Mk1/1A and a commitment for the Mk-2 variant, the IAF has encouraged indigenous production of combat aircraft. This time, the IAF must not kill indigenous combat aircraft design capability the way it did after the HF-24 Marut project. The LCA Tejas project may have numerous flaws, but the experience gained must be used to develop the Tejas Mk-2 and the next home-grown project – the fifth generation Advanced Medium Combat Aircraft (AMCA). To cover the shortage of fighter aircraft, the IAF will have to look for foreign vendors under the Make in India scheme. But whoever wins, the single or twin-engine contractor must also be involved in the AMCA project with a commitment to produce it in a finite timeframe.

For quite some time now, there has been talk of possible selection of a single-engine fighter to equip the rapidly depleting fighter fleet of the Indian Air Force (IAF). The options being discussed are the Lockheed Martin F-16I (Block 70) and the Saab Gripen NG. Recent press reports also state that the single-engine procurement plan is to be replaced with a new proposal to include both single and twin-engine fighters, the aim being ‘to increase the number of contenders.’ Amidst these varying reports, a canard has been floated that the gap must in fact be filled by more acquisitions of the home-grown Light Combat Aircraft (LCA) Tejas. The chief contention put forth is that while the LCA Tejas may indeed be less capable than the other two or other contenders, the skill of the fighter pilots of the IAF would carry the day as it did when, the IAF’s Gnat pilots overcame the much more capable and higher performing F-86 Sabres of the Pakistan Air Force (PAF) in the Indo-Pak wars of 1965 and 1971.

While this may be intentionally meant to be flattering to the IAF pilots, it is well-known that the Folland/HAL Gnat was far superior to the F-86 Sabre in performance. The Gnat was much smaller and lighter than the Sabre weighing less than 43 per cent of the Sabre’s weight (with combat fuel – i.e. 50 per cent internal fuel), but its Bristol Siddeley Orpheus 701-1 engine enjoyed almost 66 per cent of the thrust provided by the Sabre F-86F’s J-47-GE-27 engine. This allowed for a much better thrust-to-weight ratio and therefore, almost double the rate of climb at sea level (approximately 20,000 feet/min) and acceleration as compared to the Sabre. However, the 120 PAF Sabre F -86F-40s and later, sixty ex German Air Force Canadair Sabre Mk 6s provided to Pakistan through Iran – all had the slatted wing providing better instantaneous turn rate and better slow speed handling than the Gnat. The higher thrust Orenda-14 engine on the Canadair Sabre Mk 6 received in 1967, provided much improved performance during the December 1971 war with India.

However, in all the five Sabre kills by the Gnat and two Gnat kills by the PAF Sabres in September 1965, and seven Sabre kills by IAF Gnats and two Gnats kills by PAF Sabres in the 1971 war, almost all were concluded within the first 30 seconds of engaging in combat hardly, time to really get into a one-on-one match of skill. In all cases, the victims were surprised by the attacker and were unable to convert from defence to offence. At best, some managed to get away. Remarkable and courageous was the case of Flying Officer NJS Sekhon PVC who was able to accelerate immediately after take-off to engage six Sabres attacking Srinagar on December 14, 1971. He achieved hits on two Sabres in a low-level turning fight, but was eventually overcome by sheer weight of numbers. It was the superior performance of the Gnat that allowed Sekhon to get airborne in the midst of an attack and catch up with the much faster Sabres attacking Srinagar.

The Folland Gnat was designed as a light and economical fighter that was rejected by the RAF who instead invested in the Hawker Hunter. Only the IAF inducted the Gnat and then HAL manufactured it in India. Finland and Yugoslavia inducted small numbers, but then rejected it for severe maintenance and design shortcomings. The IAF Gnat faced severe technical issues with its unique and radical control system, braking, armament and electrics. During both the wars, the number of times IAF Gnat pilots found themselves with guns jammed sitting behind enemy Sabres, was most embarrassing. Several technical branch officers and airmen of the IAF found themselves facing court martial during the war, but HAL could never solve the problems.

Serviceability of the Gnat was also an issue during the 1971 War when, of the 64 Gnats on strength in the West, on an average, only 29 were available on the flight line through the 14-day war. On the Eastern front, the figure was 24 serviceable of 48 Gnats. Flying on average 1.5 sorties per Gnat per day, the fleet of Gnat fighter jets clocked 1,116 sorties by the end of the war. Worse off was the HAL HF-24 Marut fleet operating from Uttarlai (Barmer, Rajasthan). The Maruts inducted in 1967, had moved from Pune to Jodhpur and then to the forward base at Uttarlai. The technical problems of the Marut were legendary in the IAF. HAL had already given up firing all four guns when vibration caused the control system to hard-over and kill its test pilot just before the war. Massive fuel and hydraulic leaks and damage to wing leading edges during jettisoning of the wing drop tanks were serious concerns for the pilots.

Of the 32 Maruts available between the two amalgamated squadrons, an average of only 15 were serviceable on any given day flying only 0.6 sorties per Marut per day totalling only 127 sorties by the end of the war. No amount of pilot or technical skill could overcome these fundamental problems. Fortunately, in that war, the IAF fielded in much larger numbers the then state-of-the-art aircraft such as the 97 Sukhoi Su-7s and the 112 MiG 21FL. The 98 of the older Hawker Hunter also provided a stable multi-role fighter that offered better performance. These aircraft took on the brunt of the highly punishing offensive role and also, the crucial defensive roles. Had the IAF fielded a force composed largely of HAL Gnats and Maruts, the outcome would clearly have been catastrophic.

It is with this background that it is important to understand where the LCA Tejas stands amongst its competitors. Make no mistake; the LCA Tejas is a technological achievement beyond our imagination. To overcome the large number of setbacks, master never-before-seen technology and, yet persevere amidst a hostile international aviation industry and sometimes, sceptical national media, is worthy of the highest praise. Yet it is important not to lose one’s head in the euphoria. As is well known, the LCA Tejas falls well short of its design performance goals set out in 1982 amongst several hundred other design shortfalls and observations.

A crucial criterion is the ability to turn or change direction rapidly so as to throw off an attacker or turn to face him. The LCA Tejas turns at a sustained rate of approximately 12 degrees per second at its limit load factor of 8G, which is about what the MiG-21 of 1957 vintage turns at. Even the IAF’s 33-year old Mirage 2000 turns at approx 16 degrees per second. This means that by the time the Mirage 2000 turns through 180 degrees in approximately 11 seconds, the Tejas would have turned through only 132 degrees. The F-16 can similarly achieve 16 degrees per second at 9G load factor allowing it to turn much faster than the LCA Tejas.

The range of the LCA Tejas or its ability to strike targets at long ranges is also stated to be a matter of concern when compared to other contemporary single-engine fighters. The agility of the LCA Tejas, i.e. the time taken to achieve a given rate of turn or pitch, is also limited by its conservative fly-by-wire control laws which are yet to prove departure protection. The ADA/HAL has been dragging its feet for several years on spin-testing that is necessary to prove that the aircraft cannot be inadvertently spun during combat. No amount of pilot skill will be able to overcome these vehicle limitations. These, and a myriad other complicated issues mean that the LCA Tejas may have to depend largely on Electronic Counter Measures (ECM), Stand-Off Weapons and refusal to engage in close combat to ensure its own survival against aircraft such as the PAF’s F-16 and the PLAAF’s J-10, J-11, J-16 and J-20.

By placing an order for 123 LCA Tejas Mk1/1A and a commitment for the Mk-2 variant, the IAF has encouraged indigenous production of combat aircraft. This time, the IAF must not kill indigenous combat aircraft design capability the way it did after the HF-24 project. The Tejas project may have numerous flaws, but the experience gained must be used to develop the Tejas Mk-2 and the next home-grown project – the fifth generation Advanced Medium Combat Aircraft (AMCA). To cover the shortage of fighter aircraft, the IAF will have to look for foreign vendors under the ‘Make in India’ scheme. But whoever wins, the single or twin-engine contractor must also be involved in the AMCA project with a commitment to produce it in a finite timeframe.

Click to buy (Vol. 33.2 Apr-Jun 2018)

Given that not all engagements will take place against enemy high-performance fighters, it makes sense to have a judicious mix of LCA Tejas and other higher performance fighters in the IAF’s force structure of tomorrow. Every cricket team captain plays with a mix of players of varied performance capabilities. The few average players can be used on the off-side and along boundaries, but not as close-in fielders or as the wicket keeper.

The Tejas is a proud reflection of national technological prowess and must indeed be celebrated as such. The IAF is already inducting significant numbers as stop gap until true 4.5 gen fighters are available but to imagine that the IAF would survive on a largely Tejas force is tantamount to a Captain hitting his own wicket!!