Indian Air Force News & Discussion - 15 Dec 2016

shiv · Post by **shiv** » 21 Mar 2018 19:49

prashantsharma wrote:
Lalmohan wrote:shiv - from what I have read elsewhere about mig21 handling:

it has fantastic acceleration, agility and raw dogfighting ability coupled with high speed sprinting to and from targets, tight turning circles, etc. which make it a phenomenal - small and agile fighting platform: this is why pilots love it, pity about the short range and until recently not much BVR capability

the delta wing however also makes it high drag in a turn - which has disadvantages in terms of manouvering AND makes for high speed landings - which are tricky to manage; this is where the criticisms come from - and to be honest, a high speed landing is always dangerous

I dont recollect any crash of a mig-21 being attributed to its "high landing speed"

It is somewhat counterintuitive - but there are several explanations that connect the high landing speed with accidents. (This is not my personal knowledge - but from a couple of sources - including one I will try and find and post). A minimum speed is required to stay in the air and that speed is reduced as the plane comes down to land. Somewhere around 340 kmph the plane will stop floating and descend to the runway if it slows down more - so it is essentially approaching its stalling speed. One of the "problems" about the MiG 21 is that it apparently does not give warning signals like shaking and juddering at stalling speed. So while landing there is a critical speed point at which the pilot has to touch down. If he cannot touch down for some reason - say he has overshot - this is the point where the MiG 21 apparently acts funny. For the pilot to "go round" for another landing by aborting one landing - pilots have a natural tendency to pull the stick back to raise the nose. Unfortunately - when the MiG 21 is at that critical velocity raising the nose actually drops the speed further and the plane stalls and may hit the ground. (Apparently this "pulling stick back" is OK in other aircraft). For the Mig 21 (I have read) that the right thing is to point the nose down (counter-intuitively) and rev up the engine (afterburner) to build up speed before pulling up the nose.

This is second and third hand knowledge - but I am reasonably sure of its accuracy. I wonder if Abhibhushan can chip in here..

fanne · Post by **fanne** » 21 Mar 2018 19:53

didn't some techie found a issue that when solved, the MIg 21 stopped crashing? It happened just after Hawk buy was announced.

ks_sachin · Post by **ks_sachin** » 21 Mar 2018 19:57

prashantsharma wrote:
Lalmohan wrote:shiv - from what I have read elsewhere about mig21 handling:

it has fantastic acceleration, agility and raw dogfighting ability coupled with high speed sprinting to and from targets, tight turning circles, etc. which make it a phenomenal - small and agile fighting platform: this is why pilots love it, pity about the short range and until recently not much BVR capability

the delta wing however also makes it high drag in a turn - which has disadvantages in terms of manouvering AND makes for high speed landings - which are tricky to manage; this is where the criticisms come from - and to be honest, a high speed landing is always dangerous

I dont recollect any crash of a mig-21 being attributed to its "high landing speed"

http://www.bharat-rakshak.com/IAF/Aircr ... odyut.html

shiv · Post by **shiv** » 21 Mar 2018 20:02

fanne wrote:didn't some techie found a issue that when solved, the MIg 21 stopped crashing? It happened just after Hawk buy was announced.

Fighters (as you know) are complex machines - so there are multiple causes. I have heard pilots telling me that there is a monster of a difference between flying an HPT-32/PC-7 and then Kiran versus getting into a MiG 21 which is a wild and powerful horse. An AJT like the Hawk is a "half-wild" horse - which gives pilots some of the sensations that a Mig 21 gives - because I believe flying a high performance fighter is an intense physical experience that affects every cell of the body and can blow the mind and is not a simple joyride. Of course fighter pilots who have experience start enjoying the thrill of feelings that would make most people crap in their pants. That said - I always remember a quote I read somewhere from a senior fighter pilot to a newbie.

When you start flying - you come with two buckets. Your bucket of luck is full and your bucket of experience is empty. Better make sure that your bucket of experience fills up before your bucket of luck runs out

shiv · Post by **shiv** » 21 Mar 2018 20:03

ks_sachin wrote:
prashantsharma wrote:

I dont recollect any crash of a mig-21 being attributed to its "high landing speed"
http://www.bharat-rakshak.com/IAF/Aircr ... odyut.html

Thanks Sachin

Lalmohan · Post by **Lalmohan** » 21 Mar 2018 20:09

shiv - your explanation of the landing problem sounds about right
all delta winged aircraft have a high landing speed and its a tricky transition because as you come in to land, the angle of attack goes up quickly and drag comes on very fast, so you can go from being a high speed aircraft to a high speed concrete block in a very short time before you are a slowing aircraft that is landing under control

srin · Post by **srin** » 21 Mar 2018 20:31

^^^
What's the landing speed of Tejas ?

Added later: Does the compound delta make the landing speed lower than pure delta ?

shiv · Post by **shiv** » 21 Mar 2018 21:05

I think the landing speed of the Tejas may be around 220-250 kmph. AFAIK it is not the shape of the wing but the wing loading. For a given weight - if the wing area is high then the plane takes off at very low speeds. Planes like the U2 were said to sometimes take off in a strong gust of wind..

Lalmohan · Post by **Lalmohan** » 22 Mar 2018 03:56

it will be the effective camber on the aerofoil as well... which on a high speed design cannot be much or it will be too draggy. the more the camber the slower you can fly with the airflow still attached

also FBW and auto land systems take a lot of the pain out of landings these days

Indranil · Post by **Indranil** » 22 Mar 2018 05:11

Shape, size, camber: all matter. To understand the wing design of Mig-21, one has to understand the history of jet design. In those days the goal for fighter jets was to go fast. Mikoyan was in the same race. The engines were getting better and better and if you study the evolution of the Mig designs, you will see the aircraft progressively went faster and faster. But in order to go fast, your wings have to be swept more and more to avoid interactions with the shock cones. This culminated in the Mig-21 having a phenomenal sweep angle of 60 degrees. Mig-21 is a phenomenal interceptor. It is cheap and light and fast. And because it light an agile, it is also a pretty decent dog fighter.

Tejas was designed much later and hence benefited with all the technological advancements. BEcause, it is unstable in nature the designers, could take other liberties. For example, because of the maneuverability that is accorded by the instability, the designers fit large wings. If you fitted Mig-21 with LCA sized wings, it will become a too stable of an aircraft. Not only that, inspite of being larger than the Mig-21s wings, LCAs wings are lighter. Thanks to the use of light weight composites. And most importantly active control surfaces allow the wing to morph for slow speed handling (the weak point of delta wings at low altitudes). The full length multi-segment active slats and the full length large flaperons provide a much more controllable aircraft at landing speeds.

But one can imagine the joys of flying a Mig-21. It is a brute of a plane. If you want to feel the rawness of high-performance flying machine, this is it. LCA is very sophisticated. It won't let you to lose control, even if you wanted to. If you lost orientation, it will take over, recover the plane to level flight and then give controls back to you.

Philip · Post by **Philip** » 23 Mar 2018 03:26

Nikhil.QED!

Cain Marko · Post by **Cain Marko** » 23 Mar 2018 08:11

I always wondered what could've been if the bison would've included an engine upgrade with the rd 33. The Russians supposedly successfully tested the same. Might have made landings easier since the rd 33 is known for robust slow speed handling not to mention excellent sfc and twr, which could've helped range and endurance.

But of course the supply chain issues associated with that engine probably deterred the AF.

shiv · Post by **shiv** » 23 Mar 2018 08:43

Cain Marko wrote:I always wondered what could've been if the bison would've included an engine upgrade with the rd 33. The Russians supposedly successfully tested the same. Might have made landings easier since the rd 33 is known for robust slow speed handling not to mention excellent sfc and twr, which could've helped range and endurance.

But of course the supply chain issues associated with that engine probably deterred the AF.

It's not the engine. It's the airframe that holds the plane up in the air. The Chinese made a MiG 21 variant (F-7) whose wings were extended whose landing performance was better acc to Wiki - but as with all plane mods - this would surely have had a blowback effect on its performance elsewhere...

nachiket · Post by **nachiket** » 23 Mar 2018 11:18

Cain Marko wrote:I always wondered what could've been if the bison would've included an engine upgrade with the rd 33. The Russians supposedly successfully tested the same. Might have made landings easier since the rd 33 is known for robust slow speed handling not to mention excellent sfc and twr, which could've helped range and endurance.

But of course the supply chain issues associated with that engine probably deterred the AF.

The Mig-21's high stall (and landing) speeds were because of its highly swept and rather small wing giving it a very high wing loading. Nothing to do with any shortcomings of its engine. You could fit an AL-31 in it if you can and it would still land at 340km/hr. That is my understanding anyway.

Lalmohan · Post by **Lalmohan** » 23 Mar 2018 18:28

correct, nothing to do with the engine

Rakesh · Post by **Rakesh** » 24 Mar 2018 02:08

Indian Air Force Claims China's J-20 Stealth Fighter Jets Are Not Undetectable
https://sputniknews.com/asia/2018032310 ... table-iaf/

SiddharthS · Post by **SiddharthS** » 24 Mar 2018 02:48

Maybe this has been already pointed out but Chinese seems to have stolen J-20 design from Common Affordable Lightweight Fighter (CALF).

Kartik · Post by **Kartik** » 24 Mar 2018 03:28

Interesting picture of an upgraded Mirage-2000TI with MICA missiles on the wing-root. AFAIK, there is no other known picture of an IAF Mirage-2000I or TI showing MICA missiles mounted on non-wing hardpoints. French Mirage-2000-5s have been seen with MICA missiles carried on fuselage mounted pylons but IAF Mirage-2000H/TH lacked those hardpoints.

Would allow for some configurations where the Mirage-2000I/TI could carry upto 7 or more MICA missiles with drop tanks. Great for escort missions where high value assets such as AWACS or tankers may need to be protected by a couple of fighters.

pic credit: Vayu Aerospace

Added later: Seems like a single Popeye/Crystal Mace bomb is being carried on the centerline.

Cain Marko · Post by **Cain Marko** » 24 Mar 2018 04:31

^ how is this different from say...this?

This is one area where the Mirages are leagues ahead of the mk1 tejas. Payload

Rakesh · Post by **Rakesh** » 24 Mar 2018 05:34

Listen to what he says about the J-20....then for some weird reason the video goes mute!

John · Post by **John** » 24 Mar 2018 06:17

Cain Marko wrote:^ how is this different from say...this?

This is one area where the Mirages are leagues ahead of the mk1 tejas. Payload

Not sure I would say leagues ahead you can say that about Rafael but not M-2000.

shiv · Post by **shiv** » 24 Mar 2018 07:42

Cain Marko wrote:
This is one area where the Mirages are leagues ahead of the mk1 tejas. Payload

I didn't understand this comment. Could you elaborate?

Cain Marko · Post by **Cain Marko** » 24 Mar 2018 09:11

shiv wrote:
Cain Marko wrote:
This is one area where the Mirages are leagues ahead of the mk1 tejas. Payload
I didn't understand this comment. Could you elaborate?

It carries about 3 tons more than the mk1 iirc.

Cain Marko · Post by **Cain Marko** » 24 Mar 2018 09:17

John wrote:
Cain Marko wrote:^ how is this different from say...this?

This is one area where the Mirages are leagues ahead of the mk1 tejas. Payload
Not sure I would say leagues ahead you can say that about Rafael but not M-2000.

Maybe.... But the difference in payload is not small, almost double.

Cain Marko · Post by **Cain Marko** » 24 Mar 2018 09:25

Rakesh wrote:Listen to what he says about the J-20....then for some weird reason the video goes mute!

Yeh jo aapka su30 ka radar hai na, Kai kilometers mein pick up kar lega usko...

Nice

shiv · Post by **shiv** » 24 Mar 2018 09:26

Cain Marko wrote:
shiv wrote: I didn't understand this comment. Could you elaborate?
It carries about 3 tons more than the mk1 iirc.

It is meant to carry more. It is larger, heavier and despite a larger wing area has a higher wing loading than the Tejas. Tejas has a better thrust weight ratio. Tejas t/w ratio is leagues ahead. One would expect the Tejas to be more stealthy and more agile

Cain Marko · Post by **Cain Marko** » 24 Mar 2018 09:33

^No doubt and no disagreement. What I shouldve probably said is that this is the only area the mk2 will have to catch up with the mirage.

shiv · Post by **shiv** » 24 Mar 2018 09:49

Not really. The Mirage is a bigger aircraft and a different one.

jaysimha · Post by **jaysimha** » 24 Mar 2018 09:50

https://www.drdo.gov.in/drdo/pub/npc/20 ... 3march.pdf

IAF fighter base cleared, to add muscle against Pak
New Delhi: The Cabinet Committee on Security (CCS) headed by Prime Minister Narendra Modi on
Wednesday cleared a long pending Indian Air Force (IAF) plan to set up a forward fighter base close to Deesa
in Banaskantha district, near India’s western border in northwest Gujarat

Cain Marko · Post by **Cain Marko** » 24 Mar 2018 13:26

shiv wrote:Not really. The Mirage is a bigger aircraft and a different one.

Different? Obviously
Bigger? We'll see. The mk2 is likely to be bigger than the mk1 too.

shiv · Post by **shiv** » 24 Mar 2018 14:56

Cain Marko wrote:
shiv wrote:Not really. The Mirage is a bigger aircraft and a different one.
Different? Obviously
Bigger? We'll see. The mk2 is likely to be bigger than the mk1 too.

And because they are different the differences should not be surprising. Only the expectation of similarity is surprising. I don't know what mk2 is.

Lalmohan · Post by **Lalmohan** » 24 Mar 2018 17:09

the tejas has gone from a simple replacement for the Mig21-FL to a Mirage2000-lite
there is a MASSIVE difference in terms of capability and engineering required to get from one to the other and not to be underestimated
we have something in between now, which has its own potency and will be deployed as such

John · Post by **John** » 24 Mar 2018 17:18

Cain Marko wrote:
John wrote: Not sure I would say leagues ahead you can say that about Rafael but not M-2000.
Maybe.... But the difference in payload is not small, almost double.

LCA only lists payload and even then there is lot of ambiguity in that with varying from 3.5 tons to 4.0 tons where as Mirage-2000 lists max external stores clearly. Is the former list max payload with fuel internal i bet that is the case. But if you do the math using numbers available it is not big difference when loaded with internal fuel. IAF has stated LCA can similar payload as Mirage-2000 and Mig-27 in the combat missions

Mirage-200D
Empty Weight:7.5 tons
Internal fuel: 3,160 kg
Max weight: 17 tons

LCA
Empty weight:6.5 tons
Internal fuel:2.5 tons
Max takeoff weight:13.5 tons

SaiK · Post by **SaiK** » 24 Mar 2018 17:30

Darn.... Why? What is the big advantage of crapping out like this? IMHO, we could have played more games w.o. sharing these infos.

Air Chief Marshal B.S. Dhanoa, while addressing the media at Halwara on Thursday, said that signals from the J-20s can be picked up easily by existing radar from several kilometers away against the currently held belief.

And... the russkies. Ugh

Rakesh · Post by **Rakesh** » 24 Mar 2018 18:17

Look at it this way....when you deflate their biggest trump card, they will think twice before attempting some misadventure. Without supremacy in the air, victory becomes much harder.

SaiK · Post by **SaiK** » 24 Mar 2018 18:20

Aahh.. I'm assuming we are playing an NT game.

nam · Post by **nam** » 24 Mar 2018 18:53

J20 flies around with a massive canard. Only the chinis don't think it helps in stealth.

It is a big jet with under powered engine. Hence they need canards for better lift... throwing the stealth out of the window.

Philip · Post by **Philip** » 24 Mar 2018 20:06

Personally, burdening the little LCA originally meant to be a MIG-21 replacement at low cost, with M2K capabilities has hampered the programme and delayed its induction.The MK-1 should've been a simple clean interceptor/ air combat fighter, with a limited CS/GA role and payload. MK-1A an improvement with an AESA radar.Both preferably with integral guns, not gun pods.After 120 of these built, the experience being factored in the MK-2 which with a more powerful engine should be built for at least another 120 aircraft with increased strike capability with PGMs.

Remember that our MIG-27s tasked for GA/CS have heavily armoured cockpits which the LCA does not have.Aircraft for strike from the medium cat. upwards esp. twin-engined,would have the greater range , payload and extra sensors and eqpt. for their multi- role purpose.The LCA would suffer losses when used in the GA/CS role due to the huge anti-air defences of today plus lack of armour. Why we have not developed a dedicated armoured Jag for GA/CS since it is twin-engjned and has better survivability beats me.It could even have some export potential as the virtues of legacy A-10 and SU-25s are being appreciated in today's ME battlefields.Even the armed Hawk was shot down!

Aircraft are far more surviveable than attack helos.The
Apache had a torrid time in Afghanistan and was even on ond occasion withdrawn from combat because oc the pasting it recd.! One must remember the rugged SU-7 we used in '71 for GA, etc.It served magnificently surviving sidewinder missile hits and heavy AAA fire.Pushpinder Chopra's fine "SU-7, Whale of a fighter" account of its history is a v.good read.Wingco Mangat's aircraft is in the Palam air force museum, a testament to its toughness.

Kakkaji · Post by **Kakkaji** » 24 Mar 2018 21:41

Philip wrote:Personally, burdening the little LCA originally meant to be a MIG-21 replacement at low cost, with M2K capabilities has hampered the programme and delayed its induction.The MK-1 should've been a simple clean interceptor/ air combat fighter, with a limited CS/GA role and payload. MK-1A an improvement with an AESA radar.Both preferably with integral guns, not gun pods.After 120 of these built, the experience being factored in the MK-2 which with a more powerful engine should be built for at least another 120 aircraft with increased strike capability with PGMs.

Agree 100% with the above part

Lalmohan · Post by **Lalmohan** » 24 Mar 2018 21:58

the mission where fast jets fly low and drop dumb bombs on top of enemy assets is no longer viable. the lethality of air defences means that attacks have to be made at stand off ranges or face very high attrition. gulf war 1 alone showed that even super duper tornado's were highly vulnerable to AAA in the field with iraqi units

insisting on fighting this mission would be a bit like rajput's insisting on charging mughal guns head on (again)