India AMCA Program

[Bhartiya Sainik]

https://twitter.com/i/web/status/1891128618207604907

HAL shys away from rapid prototyping so we don't see them putting out frames faster. HAL has the capability to put out a flying prototype without the necessary sub system but that's does not fit into HAL Philosophy of manufacturing

1:1 mockup, engineering model, static model, exhibit model, etc, whatever people wan't to call it, this exhibit model is made with wood &/or fiber. There are hardly any joints, rivets, real panels, etc. The static model is not for development into flight model.
As per DRDO & PSU info on various forums + AMCA bulkhead metal cutting happened in 2022 + as per these ADA guys it'll take 4 more years to roll out the prototype = no full structure available yet.
So beware of Youtubers, journalists saying something semantically wrong like "in THEORY... FLIGHT with THIS Aero India model".
Flight is practical, not theory. Makers reveal a flyable prototype only at the manufacturing facility with runway obviously, but Yelahanka is just a simple airbase.

 

[Bhartiya Sainik]

A collage of AMCA's CAD 2D front view projections from various artists, in different resolutions, some resized.
If anybody has more 2D front views, diagram, sketch, etc, please share.

 

[Bhartiya Sainik]

Continuing the chain of posts for weapons in AMCA's IWB which is officially quoted 4.2m X 2.2m,
After observing the designs of all BVR-AAMs made globally, and intention of F-35 & J-35 to increase their IWB capacity to 6 AAMs, I had shown by diagrams that only 4 big-fin Astr-1/2 AAMs can fit in IWB but,
6 staggered Astr-2 short-fin AAMs (like AIM-120-D in F-22),
or 6 modified Astr-3 SFDR,
or 8 folding-fin Astr-2 AAMs can fit in (like Chinese PL-15).

I took the CAD of Astr-2 big-fin by artist "Akela freedom" & edited in Paint to match short-fin version made by artist "Kuntal Biswas" which is also identical to AIM-120-D. So the forward fixed fin has been shortened & shifted forward & rear fin leading edge more swept back, that's all, simple quick edit.

View attachment 73595

Now we can see the comparison more clear & precise, 4 & 6 big-fin AAMs vs 6 short-fin AAMs in the outine of official dimension of IWB. Unfortunately an updated CAD is not released yet by any artist or DoD.

View attachment 73596

I did this few weeks back but I waited for Aero-India, hoping they would officially increase the IWB capacity & showcase, but didn't happen. But this is not an up-hill task & can be done easily till IOC jet.

View attachment 73597

There is no separator wall in the IWB. 1 door panel slightly overlaps on the panel of other side door, means both doors have to open full to drop any weapon, exposing full IWB.
I hope this gets corrected in IOC jet.

So far we have seen multiple CADs & static models with slight differences.
Neither ADA nor the 3D artists release basic schematic diagrams, cross sections, configurations, etc. The ones available so far are low resolution & inadequate.

It is difficult to confirm how the inducted jet will look like & its capabilities.
So taking the most convincing CAD front view & superimposing the IWB dimension of 2.2m width & 0.75m depth, along with BVR-AAMs from TEDBF CAD, it seems 6x Astr-2 short-fin version with 178mm body diameter would fit in IWB easily with or w/o staggering.
SWB is also possible.
With 1.5 ton IWB capacity, 6x BVR-AAMs + 2 CCMs = 6x154 + 2x88 = 1,100 Kg, 1.1/(12+6.5+1.1)=5.6% of STOW.
Wet T/STOW ratio = 2x98 KN / 9.8 / (12+6.5+1.1) = 1.02
With 50% fuel used & firing 4 BVR-AAMs, with 2 CCMs & 2 BVR-AAMs left, wet TWR = 2x98 KN / 9.8 / {12+3.25+(2x154 + 2x88)/1000} = 1.27

 

[Bhartiya Sainik]

AMCA width 36'6" / length 57'9" / empty weight 12 tons / Internal fuel 6.5 tons.
F-18E/F width 44'8" / length 60'1" / empty weight 14.5 tons / Internal fuel 6.7 tons.
After seeing skinny 4gen F-18 SH with same 2x F414 engines & enjoying versatility of high loadout including EW pods, i decided to push AMCA's design potential as per its dimensions.

5gen design brings AAMs very close inside IWB in staggered order. The fins of AAMs were clipped.
6gen focuses on more capacity of everything & AMCA is being pitched as 5.5gen, so capacity should be increased IMO.

Bcoz AAMs already don't have 100% PK (Probability of Kill) & DEW-CIWS or DECM (Directed Energy Counter Measure), so the next step is to pack more AAMs in same space.
NOTE- After shooting BVR-AAMs the tactic is not to merge for dogfight like in movies, videogames, but make U-turn & continue to stayout of enemy's AAM's NEZ till all BVR-AAMs are depleted.

The PL-15 might be 1st medium range AAM with folding fin.

But with AMCA's 0.75m IWB depth, 135 degrees of folding is not required, just 45 degrees up/down would suffice. The launcher would punch out the AAMs straight, so the folded fins would be aerodynamically in line with separation trajectory, would take less time to unfold & start flying the AAM.
Astr AAM dia. is 178mm.
In the 2,200mm wide IWB, 2x4 or even 2x5 AAMs might fit tightly.
If the folding can be done within 180mm width then 5x180=900mm would be needed for 5 AAMs, leaving 200/6= 33mm gap b/w the AAMs & with IWB side walls.
A scaled notional diagram of 3/4/5 AAMs looks like following:

With 10x BVR-AAMs + 4 CCMs = 10x154 + 4x88 = 1,892 Kg, 1.892/(12+6.5+1.892)=9.3% of STOW (earlier 1.1 tons was 5.6%).
Wet T/STOW ratio = 2x98 KN / 9.8 / (12+6.5+1.892) = 0.98 (earlier 1.02)
With 50% fuel used & firing 6 BVR-AAMs, with 2 CCMs & 4 BVR-AAMs left, wet TWR = 2x98 KN / 9.8 / (12+3.25+0.792) = 1.24 (earlier 1.27)

Now comparing this new potential with F-18 looks like following:

It looks like may be AMCA airframe volume can be expanded some more.

 

[Bhartiya Sainik]

I did the 10+4 concept with folding fin version of Astr-2 with regular solid fuel rocket motor.
I had shown earlier in Dec'2024 about Astr-3 SFDR too.

> current design of Astr-3 SFDR is making it difficult to fit more than 2x in each IWB due to its long Ramjet intakes.

> if intakes are modified near fins, then it can aid in staggering 3x AAMs easily.

> with folding fins, 3x is possible in each side IWB w/o staggering.
200mm dia. + 2x50mm intake width = 300mm for each AAM.
In IWB width of 1,100mm, the AAMs would take 3x300mm = 900mm giving 200mm/4=50mm gaps.

I think artist Kuntal Biswas didn't give front view of SFDR, atleast i don't have it, so i took that of Meteor AAM by Akela-Freedom for notional representation.

 

[Bhartiya Sainik]

while searching for F-18 SH's stealth pod, i found F-18 SH stealth derivative by some artist on Reddit site:
( https://www.reddit.com/r/FighterJets/comments/2aqddg )

BTW, this is 11 years ago
Unfortunately 2D views of this 3D art are not available.

We also had a caret-intake model earlier & F-18 SH has such identical intakes.
So just for the sake of some similarity & 2xF414 engines, let's compare the F-18 SH upgrade proposed with CFT + stealth pod, with AMCA.
Otherwise 4gen vs 5gen doesn't compare, different components by different makers in different era.
The aerodynamics are also different.
This is just to see what the 2xF414 engines are pushing.

F-18 SH empty weight = base + 2x CFT = 14.5 + 2x0.4 = 15.3 tons.
Internal fuel = 6.7 tons + 3.2 tons total in 2x CFTs = 9.9 tons.
AAMs tons = 4x AIM-120 + 2x AIM-9X = 2*(162+162+85)/1000 = 0.818 tons.

AMCA AAMs tons = 4x154 Kg Astr AAMs = 0.616 tons.

Wet TWR should be at least 1.1
Bcoz 196 KN wet thrust is 62.8% of F-22's, so to have same TWR, all the weights on average should be 62.8%. The empty, fuel, weapons, external load weights can vary but total STOW & MTOW should not exceed 62.8% ideally. But AMCA's AA-STOW is 19.116 tons (65.8%), AG-STOW is 20 tons (68.3%) & MTOW is 27 tons (71%) & that of F-18 SH is even more - 90%(4+2 AAMs) & 79% MTOW. For us not having engine options YET it is a desperate compelling situation, but USA's or any maker nation's domestic engines can have more thust than export versions, which could be kept classified.
Moreover, bcoz F-18 has perpendicular wing with higher drag & lift for carrier ops, but AMCA being AF jet has better swept wings,
hence F-18 can haul more weight, but AMCA would cruise much better, longer, farther.

Let's see approximate scaled comparison b/w AMCA's caret-intake model, DSI model & F-18 SH with CFT & EWP model.

From top view, even in the F-18 non-CFT base model the forward fuselage is very skinny, the intakes start much back near LER, wing span more but area is less than AMCA, but still its empty & fuel weights are more.
From front view, AMCA appears more voluminous than non-CFT base model, but the CFT model looks little more voluminous. But the fuel weight difference is a lot - 6.5 Vs 9.9 (6.7+3.2) tons.

The EWP (External Weapons Pod) arranges 4x AAMs in 2 layers, 2x2 order. But for a brand new design, same 4 AAMs would be arranged linearly, like in AMCA or any steath jet.