LCA Tejas Mk1 & Mk1A - News and discussions
- Thread starter Ashwin
- Start date
-
- Tags
- indian defence forum
First batch of Uttam MK1A which was earlier slated for Tejas MKI1A from 42nd airframe was supposed to be with 912 TRMs based on GaAs semiconductor tech. But later the plan changed for entire 73 Tejas MKIA having only Elta EL/M-2052 and Uttam being the sole radar for the second batch of 97 jets. But now because of the timeline of this second batch's induction(in 2030s) and maturity of GaN tech, entire 2nd batch will get GaN TRMs based AESA radar.
. Anyways, eagerly waiting for MK1A delivery to begin
0 Mk1A are ready. They got concessions to be able to deliver some this year.
7 MK1A have engines. I wonder if all those are new engines
20 actually, another 2 aircraft that have not been painted to IAF Tipnis Grey can also be seen in the first pic.
What is the current situation with the Mk1A engines? Because sometimes the Tejas Mk1A halfheartedly seems like a semi dead program, sure we can develop most of the other related components on our own now but without an engine of our own or a reliable supplier, america controls how many jets we can make. The GE F414 deal seems to be going nowhere as of now and without a reliable supply of it, how long till we can induct a reliable number of it? Since induction can be from as early as 2028 to 2030, how long till we produce a meaningful number to make a difference for Tejas Mk2 or MK1A atleast.
Don't get me wrong, I'm not trying to be a hater. just concerned over some of the potential problems we are and could face in future and hope we can do something to make sure we can built a good squadron of Tejas for our Airforce.
If we had perfected the Kaveri with reduced weight and new afterburner, we could potentially scale up the order of Tejas and make a Tejas Mk1b which uses the kaveri engine hopefully, (Although I prefer a more aesthetic intake if we did so)
Since the kaveri is an uprated engine and has similar thrust to the GE F404-GE-IN20 engine used in the Tejas,
If we use the Breguet Range Equation simplified for Aircrafts:
Range = (Cruise Speed/Thrust Specific Fuel Consumption in dry mode) x (Lift to Drag Ratio) x Natural Logarithm(Initial Gross Weight of aircraft/Final Weight after fuel is burned)
If we input the values, V = 900km/hr, L/D = 13, Fuel Mass = 2458Kg, W_initial(GEF404) = 13500Kg, W_Final(GE404) = 13500-2458 = 11042kg & W_Initial(Kaveri) = 13600kg and W_Final(Kaveri) = 11142Kg, TSFC(GE F404) = 0.77 kg/kgf·hr and TSFC(Kaveri) = 0.824 kg/kgf·hr.
So for GE F404-IN20 Engine, we get: Range = (900/0.77) x 13 x ln(13500/11042) = 3053.9km
and for Kaveri Engine, we get a: Range = (900/0.824) x 13 x ln(13600/11142) = 2830.5km
Although this is the max theoretical range under ideal conditions, to find the real world range, we would have to apply a correction factor usually seen in typical hi-lo-hi profile mission with fully loaded weapons, the correction factor could range from 0.14 - 0.18 (0.15 most common) . So to calculate
Real Combat Range = Theoretical Range x Correction Factor,
So for Tejas with GE F404, Combat Radius = 3053.9Km x 0.15 = 458.085km
and for Tejas with Kaveri, Combat Radius = 2830.5km x 0.15 = 424.575km
This makes the difference in combat radius between both being 33.5km or an efficiency difference of roughly 7% which isn't a major difference. Although these are just general estimates by me cause some values can differ and change the range, it makes sense why we can use the current kaveri or a further upgraded lightweight one using Blisk in the low and high pressure stages and maybe materials with better strength to weight ratios for greater performance and range. Not to mention with external tanks, we can significantly increase the range of the jet during operation.
The Kaveri program should be treated with absolute importance for self dependency of our country and to boost our aviation Industry.
Don't get me wrong, I'm not trying to be a hater. just concerned over some of the potential problems we are and could face in future and hope we can do something to make sure we can built a good squadron of Tejas for our Airforce.
If we had perfected the Kaveri with reduced weight and new afterburner, we could potentially scale up the order of Tejas and make a Tejas Mk1b which uses the kaveri engine hopefully, (Although I prefer a more aesthetic intake if we did so)
Since the kaveri is an uprated engine and has similar thrust to the GE F404-GE-IN20 engine used in the Tejas,
If we use the Breguet Range Equation simplified for Aircrafts:
Range = (Cruise Speed/Thrust Specific Fuel Consumption in dry mode) x (Lift to Drag Ratio) x Natural Logarithm(Initial Gross Weight of aircraft/Final Weight after fuel is burned)
If we input the values, V = 900km/hr, L/D = 13, Fuel Mass = 2458Kg, W_initial(GEF404) = 13500Kg, W_Final(GE404) = 13500-2458 = 11042kg & W_Initial(Kaveri) = 13600kg and W_Final(Kaveri) = 11142Kg, TSFC(GE F404) = 0.77 kg/kgf·hr and TSFC(Kaveri) = 0.824 kg/kgf·hr.
So for GE F404-IN20 Engine, we get: Range = (900/0.77) x 13 x ln(13500/11042) = 3053.9km
and for Kaveri Engine, we get a: Range = (900/0.824) x 13 x ln(13600/11142) = 2830.5km
Although this is the max theoretical range under ideal conditions, to find the real world range, we would have to apply a correction factor usually seen in typical hi-lo-hi profile mission with fully loaded weapons, the correction factor could range from 0.14 - 0.18 (0.15 most common) . So to calculate
Real Combat Range = Theoretical Range x Correction Factor,
So for Tejas with GE F404, Combat Radius = 3053.9Km x 0.15 = 458.085km
and for Tejas with Kaveri, Combat Radius = 2830.5km x 0.15 = 424.575km
This makes the difference in combat radius between both being 33.5km or an efficiency difference of roughly 7% which isn't a major difference. Although these are just general estimates by me cause some values can differ and change the range, it makes sense why we can use the current kaveri or a further upgraded lightweight one using Blisk in the low and high pressure stages and maybe materials with better strength to weight ratios for greater performance and range. Not to mention with external tanks, we can significantly increase the range of the jet during operation.
The Kaveri program should be treated with absolute importance for self dependency of our country and to boost our aviation Industry.
Last edited:
HAL CMD had said engine supply will stabilize June-July onwards. GE recently announced a $42 million investment in the Lynn plant where F404s are made.
GE Aerospace to Invest Another $1B in U.S. Manufacturing | GE Aerospace News
CINCINNATI – March 9, 2026 – GE Aerospace plans to invest another $1 billion in its U.S.
GE delivers sixth F404 engine for Tejas Mk1A to HAL, but delays continue
GE delivered only six engines to HAL in the last fiscal which ended Tuesday, short of the 11 promised as per the revised timeline.
theprint.in
Only six engines have been delivered to HAL in the last fiscal which ended Tuesday, short of the 11 promised as per the revised timeline.
Confirmation on the sixth engine came as ThePrint reached GE to inquire about the delay. “GE Aerospace has handed over the sixth F404-IN20 engine against the order from 2021. GE Aerospace and HAL continue to work closely to ensure clear line of sight of production schedules for the F404 engines,” read a statement by a spokesperson for GE Aerospace.
HAL sources said they have yet to receive the sixth engine in India, adding that the handover could have taken place in the US.
Sources in the defence establishment said GE has informed HAL that the delay in deliveries is due to the ongoing US-Israel and Iran war.
Earlier this year, ThePrint had reported that despite what the HAL claims, the first lot of the Tejas Mk1A, which was to be delivered to the Indian Air Force (IAF) in March 2024, is likely to be inducted latest only by June-July this year—after a delay of over two years.
Incidentally, the IAF and the Ministry of Defence (MoD) have agreed to grant HAL certain exemptions from contractual obligations, so that the long-pending delivery of the Tejas Mk1A can start early this fiscal year. Under the new understanding, IAF will accept the aircraft if the Aeronautical Development Agency (ADA) and HAL complete the missile-firing tests, integration of radar to the electronic warfare systems, and the weapons package.
It is learnt that firing trials are complete and the certification process is underway. The three tasks were described as “completely essential” under the new arrangement.
HAL has argued before the defence ministry and IAF that much of the pending work is being overseen by ADA, and is not a manufacturing delay. Major capabilities incorporated are undergoing the certification process and should be completed by the end of April. Following this, the IAF will undertake acceptance trials, which could last a few weeks.
IAF, HAL to hold Tejas Mk1A review this month; delivery timeline hinges on mandatory requirements
NEW DELHI: With the Tejas Mk1A programme mired in persistent delays, Hindustan Aeronautics Limited (HAL) and the Indian Air Force (IAF) are set to hold a critic
With the Tejas Mk1A programme mired in persistent delays, Hindustan Aeronautics Limited (HAL) and the Indian Air Force (IAF) are set to hold a critical programme review later this month to take stock of progress and finalise a revised induction timeline, it is learnt.
Sources in the defence establishment said senior officials from the IAF and HAL will meet in New Delhi to assess the progress made on mandatory operational requirements, benchmarks considered non-negotiable for the aircraft to be accepted into service.
“The outcome of the review will be decisive. If the programme is sufficiently on track, the IAF is likely to take delivery of the first Mk1A within the next two-three months. If not, further slippages are likely,” the source said.
The mandatory requirements include completion of missile firing trials, integration of the radar with the electronic warfare suite and validation of the full weapons package.
“The IAF is pushing for clarity on when the first aircraft, already over two years behind schedule, will finally be inducted,” the source added. “We have granted certain exemptions from contractual obligations and if the mandatory requirements are met, we would take the fighter as soon as possible.”
In February, HAL declared five Mk1As ready for delivery, saying the aircraft had incorporated “major” contracted capabilities. However, sources indicate that while the five aircraft described as “ready” incorporate key contracted capabilities, not all contracted capabilities have yet received certification, with certain mandatory clearances still pending.
Looks like the crashed aircraft has been repaired.
Engine s are made by a big country in War
Radar - EW made by a small country in war.
HAL has made a squad of Tejas without engines and parked ..
IAF unwilling to accept even a small batch with the new engines without the capabilities contracted.
Is there are any other possibilities to delay even more ?
How long and how many hurdles to crossover..
Radar - EW made by a small country in war.
HAL has made a squad of Tejas without engines and parked ..
IAF unwilling to accept even a small batch with the new engines without the capabilities contracted.
Is there are any other possibilities to delay even more ?
How long and how many hurdles to crossover..
The bigger problem is the project itself is led by an incompetent company.
Good News
Things are getting Better
With EW suite done , IAF will have a potent BVR fighter to take on J 10 and F 16
Things are getting Better
With EW suite done , IAF will have a potent BVR fighter to take on J 10 and F 16