Setting the record straight on Tejas

Understanding the Tejas Program: Debunking Misconceptions and Explaining Shortcomings

The Tejas program has often faced unfair criticism and unwarranted labeling as a failure without proper understanding of the project and the aircraft itself. While it is true that the Tejas program encountered challenges and has some shortcomings, it should not be considered a failure by any means. In this article, I aim to debunk some of the perceived problems and provide explanations for its genuine shortcomings.

Section 1: Long Development Cycle of the Tejas Program.

One thing people often forget while discussing the Tejas program is that it was not solely focused on developing a fighter jet, it was much more than that and aimed at establishing a comprehensive aerospace ecosystem in India. The program oversaw the creation of the Aeronautical Development Agency (ADA) and the development of many critical subsystems such as the Multi-Mode Radar, Kaveri Engine, airframe alloys, flight control systems (fly by wire, flight computers), avionics (e.g. self-protection jammer), etc. Thus, comparing the Tejas program to other contemporary programs like the FC 1 (JF 17) or KTX 2 (FA 50) which were solely focused on just developing a fighter jet, would be inappropriate. The aim of the Tejas program was similar in nature to that of Integrated Guided Missile Development Programme, which created the entire Missile ecosystem of India.

Nevertheless, let's examine the development cycle of the LCA Tejas for the sake of the argument.

The program began in 1983, with ADA being established in 1984 (yes, the design bureau itself was created after the program began). Requirements were issued by the Indian Air Force (IAF) in 1985, and funds were released in 1986. The design was finalized in 1990 (Design phase took nearly 4 years which is fairly standard throughout the world).[i]

The first technology demonstrator was rolled out in 1995, and the first flight although initially planned for 1997, was delayed to 2001 due to technological challenges, US sanctions in 1998, and changes in ASR (Air Staff Requirement) by the IAF in 1997.

The failure of Kaveri engine to meet the required thrust forced us to import F404 engine from the US and flaws in the Signal processing module of the Multi-Mode Radar (MMR) caused various modes to have sub optimal performance forcing us to import EL/M 2032 radar from Israel, causing further delays in the Tejas Project.

However, by late 2010 nearly all the requirements necessary for the Initial Operational Clearance (IOC) of Tejas mk1 were fulfilled. But by this time, IAF's behavior became increasingly unreasonable such as asking for in-flight refueling capability (IFR) as a prerequisite for Final Operational Clearance (FOC), which was initially planned for Tejas MK-1A, asking for addition of Helmet Mounted Display System (HMDS) as a prerequisite for IOC, even though that could have happened later on during FOC and insisting on purchasing the aircraft only after it was FOC certified even though indigenous fighters around the world get inducted with IOC certification all the time, because it allows the air forces to familiarize themselves with the aircraft (by training the pilots on the aircraft and creating the necessary infrastructure at the bases for the aircraft) while the aircraft gets FOC certified in parallel.

Eventually the government convinced the IAF to accept Tejas at IOC 2* standard (IOC 1 was achieved in 2011 where as IOC 2 was achieved in 2013)[ii] and the first Tejas Mk1 aircraft began delivery in 2015.

So even if we include all these tom fooleries of IAF in the development cycle of Tejas we can see that the Tejas program effectively started with the requirements being laid out by IAF in 1986 and concluded with the start of deliveries of Tejas mk1 to IAF in 2015 which spans a timeline of 30 years not very different from standalone fighter jet development efforts from other countries like French Rafale, Swedish Gripen, or Chinese J10.

Section 2: Concerns regarding Tejas being overweight, having less fuel capacity and reduced payload.

It is alleged that as per the ASR, empty weight of Tejas should not have exceeded 5500 kg but today it stands at 6560 kg, however It’s important to note that ADA in its Project Definition Phase(PDP) document of march 1989 had already informed the IAF that meeting the weight requirements laid out in the ASR would be extremely challenging due to the necessity of meeting the other requirements present in the ASR, this deadlock between the IAF and ADA was resolved in march 1990 when both party reached an arrangement that ADA would pursue weight reduction measures in a phased manner as weight would not be considered an immediate and non-negotiable issue anymore[iii].

However, in its 30 years of development period, ASR of Tejas was revised at least 10 times but weight requirements remained unchanged. Consequently, any weight reduction achieved by ADA was offset by accommodating the increased weight caused by the ASR changes.

Not to mention Tejas currently carries 300-400 kg of ballast(dead) weight to maintain center of gravity and HAL has been working on re-aligning Line Replaceable Units (LRUs) to remove this dead weight and make the aircraft lighter in the newer mk1a variant.[iv]

But let’s for a moment assume that its overweight and ask ourselves has this resulted in non-compliance of any other ASR parameters? The answer is no.

Currently Tejas weighs around 6560kg (take off clean weight is 9800kg) with an internal fuel capacity of 2486 kg. Around 170 kg less fuel the what was originally asked for. However, the presence of IFR capabilities means that this 170 kg can be managed easily. Not to mention the fuel systems of Tejas mk1a were modified to increase its fuel capacity, and the newer mk1a variant carries more fuel than its comparable fighters.

Another point often raised is that the maximum payload capacity of Tejas has decreased due to weight increase which is completely false. The ASR originally demanded a minimum payload capacity of 3000 kg, and Tejas offers a payload capacity of 3500 kg with full fuel and has even been tested with a payload of around 4000 kg (likely with reduced internal fuel).[v]

Section 3: Range and combat radius of Tejas is very small.

Claims regarding the Tejas's range and combat radius are often based on a 2013 The Hindu interview of Dr. K Tamilmani, the former Chief Executive of CEMILAC. In the interview, Dr. Tamilmani discussed the specifications of the Tejas Mk1 and claimed Tejas has a speed of 1350 km/h (1.25 Mach), G limit of 7G, combat radius of 400-500km and an angle of attack of less than 24 degrees[vi], However The date of publishing of the article makes it quite clear that he was talking about IOC 1 standard Tejas mk1 which had a limited flight envelope.

But now with the newer mk1a variant, its flight envelope has expanded, it now has an increased max speed of Mach 1.6, a G limit of -3.5/8G (can be pushed to 8.5G), and an angle of attack of 28 degrees so to think that the range would not have increased too would be foolish.[vii]

But before going any further let’s define some key terminologies, shall we

Range: The maximum distance an aircraft can travel (from point A to B) solely on internal fuel in most economical conditions.

Ferry Range: The maximum distance an aircraft can travel (from point A to point B) using internal fuel and drop tanks in most economical conditions.

Combat Range: The distance an aircraft can cover (from Point A to B and back to A) on its internal fuel and represents an aircraft's operational capabilities.

Although no official documents provide the updated combat radius, during the Singapore Airshow, the Tejas flew approximately 3200 km from Sulur Airbase to Changi Airport with three drop tanks and no in-flight refueling indicating a ferry range of around 3200km.

Which is comparable to the Saab Gripen C/D, a fighter in the same weight class with the same engine. So, if we extrapolate this and even consider in a 15-20% range reduction due to inefficient air intakes and aerodynamic drag, Tejas's combat range can be estimated to be between 650 and 700 km (Gripen has a combat range of 800km) which by no means is small.[viii]

Section 4: Tejas lacks an advanced EW suite

Another criticism Tejas has faced is that it lacks an advanced Electronic Warfare (EW) suite,

However before going any further let's first understand what an EW suite actually means. An EW suite consists of various types of sensors and equipment that enable the pilot to maintain situational awareness against various types of incoming threats and effectively counter them in the electromagnetic spectrum. Key components include Counter Measures Dispensing System (CMDS), Radar Warning Receiver (RWR), Missile Approach Warning System (MAWS), Self-Protection Jammer (SPJ), Electronic Support Measures (ESM), and Electronic Countermeasures (ECM) system.

Tejas was supposed to be capable of carrying an ECM pod, an internal SPJ, RWR, and CMDS.

Currently Tejas is equipped with CMDS, RWR, SDR and passive jammers however it currently lacks an internal SPJ and MAWS[ix].

Critics often emphasize on this absence of internal SPJ in Tejas Mk1, but they forget that in the 1997 ASR letter (AHQ/S96056/6/7/ASR) IAF had specified that the SPJ should preferably be internal or podded meaning although an internal SPJ was preferred it not necessary and a podded SPJ would work just fine, not to mention most of the aircrafts of this category don't have an internal SPJ.[x]

However, HAL and DRDO will have to take criticism for failing to develop an indigenous podded SPJ or integrating a foreign podded SPJ till now, but as of now a lot of progress has been made and Tejas mk1a will come with a podded SPJ developed by DARE which can be retrofitted to Tejas mk1.[xi]

Regarding the MAWS, it was not a requirement in the Air Staff Requirement (ASR) for Tejas and is not a feature present in most fighter jet of this category. Therefore, the absence of MAWS does not detract from Tejas's overall performance.[xii]

Section 5: Tejas is not indigenous enough.

Another common argument against Tejas is that total indigenous content of Tejas is only 35%. However, it is important to understand the context of this figure.

This assertion comes from the 2015 CAG report however the ADA had clarified in a parliamentary committee report that the figure of 35% refers specifically to the raw material used in the LCA airframe and not the overall content of Tejas.

The said 65% of raw materials (metallic and composite raw materials) were imported due to factors like cost-effectiveness and/or shorter delivery timelines.[xiii]

To better understand the concept of indigenization, it is crucial to understand the two ways used to quantify indigenousness of an item: value and intellectual property (IP) rights

By value, an item is considered indigenous when all the money spent on it remains within the country. For instance, if a vendor sells a product for 100 rupees but has to pay 35 rupees to a Chinese company for raw materials, the item is deemed 65% indigenous.

The second method is related to the IP rights of the item and its subsystems held within the country. For example, if a product consists of 10 subsystems and a foreign country possesses IP rights on 3 of them, the item is considered 70% indigenous.

Currently, in terms of value, Tejas is around 50% indigenous, which is projected to increase to 60% in the mk1a variant.

However, it is worth noting that focusing solely on value may be misleading.

Consider the following example, although both RD 93 and GE F404 are foreign engines, a fighter with RD 93 would be considered more indigenous value wise than a fighter with F404 engine simply because RD93 is cheaper than F404.

This highlights the limitation of using value as the sole metric for assessing indigenization and why we should focus more on using IP rights as a metric for indigenousness.

In terms of IP rights, Tejas mk1 is currently 60% indigenous as out of the 344 LRUs IP rights of 210 are held within the country.

with the mk1a variant this indigenization is expected to reach 75.5%.

Mk1a variant aims to indigenize 42 out of the 134 foreign LRUs reducing the number of foreign LRUs to just 92.[xiv]

No other fighter of this class like FA 50, JF 17, JAS Gripen C/D etc can boast about this level of indigenization.

Section 6: IAF didn't want Tejas as it had several deficiencies and was forced by the government to accept it.

Although there is some truth to this allegation, it is being spun in a completely different direction thus it is important we understand the full context.

Yes, MoD pushed IAF to accept Tejas and give it some waivers but it was not because Tejas was a bad aircraft or that ADA and HAL did a very bad job on it but because IAF was being unreasonable with its demands and were unwilling to hear any reasoning or persuasion from HAL and ADA forcing MoD to put its foot down

We often hear about how IAF was forced to give Tejas 53 waivers but what we don’t hear is that although many of the waivers given were indeed legitimate like issues related to single point defueling, inadequate fuel protection system etc and HAL and ADA are to be blamed as they should have been more proactive in solving those issues, most of these deficiencies were not critical enough to prevent the induction of the aircraft into the IAF and could have been ironed out even after being inducted.

Not to mention out of these 53 waivers, 33 were temporary in nature and were mostly resolved by the subsequent IOC-2 and FOC certification stages of the Tejas program with remaining waivers being expected to be resolved in the upcoming mk1a variant. But IAF in their stubbornness refused to accept a less than perfect aircraft even though air forces around the world do similar things all the time forcing MoD to intervene.[xv]

Section 7: Lifespan of Tejas is low compared to other contemporary fighters.

There have been claims suggesting that the lifespan of the Tejas is lower (20 years) compared to other contemporary fighters, such as the Gripen (40 years).

Firstly, the lifespan of aircraft is not measured in years but rather in flight hours.

This duration mainly depends on the durability of the airframe and engine. In the case of Tejas, its airframe has a high amount of composites, which enhances its resistance to corrosion and fatigue in comparison to airframes made of conventional materials like aerospace-grade aluminum, then how come Tejas is structurally half as good as Gripen C/D’s or F-16’s which use lower amounts of composites.

In term of engine lifespan Tejas employs the same engine as the Gripen C/D, The General Electric F404 then logically the engine lifespan should also be similar.

The truth is that the exact in-service fatigue life of Tejas is yet to be determined however Initial conservative estimates indicate a service life of 9000 hours. Each of the in-service Tejas units are fitted with a Health Up Monitoring System (HUMS) to measure airframe fatigue and come up with revised estimates for service life and It is highly likely that the estimated service life will be revised upwards to approximately 12,000 hours.

This process of revising service life estimates is not unique to Tejas, even aircrafts like the F-16 and Gripen have undergone similar revisions throughout their service. For Example, when the F-16 first entered service, its estimated service life was about 6,000 hours, which was later revised to 8,000 hours, and eventually increased to approximately 12,000 hours.[xvi]

Section 8: Claims on Tejas's Combat Endurance and Servicing requirements.

There are some claims suggesting that the combat endurance of Tejas is less than an hour compared to 3 hours of Saab Gripen and that it requires more servicing per hour of flying than other similar aircrafts.

Before delving any deeper it’s important to understand what combat endurance actually means and how it is calculated to gain a better understanding.

Combat endurance typically refers to the amount of time an aircraft can sustain operations at an altitude suitable for combat. It is determined by factors like the fuel fraction, lift-to-drag ratio, specific fuel consumption (SFC) of the engine, and mission profile.

• Fuel fraction, is the ratio of total fuel weight to aircraft's gross weight, It is a key measure in determining endurance of an aircraft.

Notably, the fuel fractions of Gripen C/D, F-16, and Tejas (with internal fuel) are all quite close, at approximately 0.23, 0.24, and 0.24, respectively.

• Specific Fuel Consumption (SFC) is the mass of fuel needed to provide the net thrust for a given period g/(s·kN) (grams of fuel per second-kilonewton) and SFC of both Tejas and Gripen C/D should be near identical (49 g/(kN⋅s)) as they use the same engine

• Lift-to-drag ratio, indicates the aerodynamic efficiency of an aircraft and the penalty the aircraft pays in order to fly through the air. While specific numbers are classified, it is known that for most modern 4th generation fighters these numbers, especially those related to long endurance i.e. cruising are very similar. In fact, they are within 10 percent of each other.

If all these critical parameters of endurance are near identical then how come the Tejas has only 1/3rd the endurance of a Gripen.[xvii]

Another Allegation against Tejas is that it is not maintenance friendly and requires 20 hours of servicing for every one hour of flying compared to only 3.5 hours of Gripen.

Although there is truth to the fact that Tejas mk1 is not as maintenance friendly as it should be and HAL has promised to make the maintenance easier in the newer mk1a variant, It is not as bad as is being claimed because during Aero India 2019, All the Tejas aircrafts selected for flying displays executed 2-3 sorties per day. Similar reports were seen during overseas airshows in Bahrain and Singapore. moreover, Tejas showcased exceptional serviceability and availability rates during IAF's Vayu Shakti and Ironfist exercises, conducting at least 3 bombing runs per day proving how these claims regarding Tejas's serviceability do not hold up under scrutiny.

Section 9: Concerns regarding limited numbers and maturity of Tejas.

Another common criticism people often make is the limited number of Tejas currently in service and concerns about the maturity of the jets and its subsystems.

As of today 40 Tejas are in active service with an additional 83 newer mk1a variant on order with deliveries scheduled to begin in 2024 at a rate of 24 aircrafts per year, resulting in 123 Tejas being deployed by the year 2028 [xviii] which by no means is a small number and would be more than enough to meet IAF's requirements at the western front vis-à-vis the Pakistani JF 17s which is its main role.

Moving on to the concerns regarding the maturity of the Tejas.

Deliveries of Tejas began in 2015 and we are currently in 2023, a period of 8 years has elapsed which is more than enough time for an aircraft to mature, Furthermore the aircraft was deployed at forward bases along the hostile Indo Pak border in 2020[xix] and also actively participated in various multilateral exercises like UAE's Desert Flag, Indian Ironfist, Yayu Shakti exercises etc, showcasing its operational capability and real world experience, dispelling any notions regarding the aircraft's lack of maturity.[xx]

It is also worth mentioning that many indigenous subsystems used in the Tejas are already widely implemented in the IAF's fleet for quite a while now, for instance, IAF's Su-30 MKIs has been using Indian mission computers, MFDs, CMDS, Indian RWR (known as Dhruti) among other things for well over a decade. showcasing the maturity and reliability of those indigenous subsystems.[xxi]

Section 10: High Operating Cost for Tejas.

There have been some claims suggesting that the per unit sale price and operating cost of Tejas are significantly higher compared to most Western aircraft which is simply untrue.

In HAL Chairman’s own words per unit cost of Tejas is 309 crores (or nearly 41 million USD) which is not far off from the sale price of similar aircrafts like Saab Gripen or FA 50.[xxii]

Operating costs of an aircraft primarily depends on 3 main factors fuel efficiency, airframe quality, and engine quality.

Tejas uses a high amount of composite materials in its airframe, which enhances it’s resistance to corrosion and fatigue when compared to aircrafts made out of conventional materials like aerospace-grade aluminum, such as the JF17. This contributes to lower maintenance and repair costs thus ultimately reducing the overall operating expenses.

Additionally, Tejas uses GE F404 engines, known for it’s exceptional efficiency and longer service life when compared to their Russian counterparts like the RD 93 used in aircrafts like the JF17. These highly efficient and reliable engines help minimize fuel consumption, and need less maintenance thereby lowering the overall operating costs.

According to a 2012 Janes report Saab Gripen's per-hour flying cost was estimated to be around $6,000. [xxiii] Considering that Tejas shares comparable parameters with the Gripen its operating cost should not exceed $7,000 per hour making it one of the most cost effective fighter jets present in the IAF's inventory most of which are of Russian origin and use inferior Russian engines and airframe materials.

In conclusion, the Tejas program has been unfairly criticized and labeled as a failure without fully understanding the intricacies of the project and the aircraft itself. While it is true that the Tejas program faced challenges and had some genuine shortcomings, it should not be dismissed as a failure and deserves more nuanced evaluation.