Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

[Singha]

>> But lower is better.

Did not get this part, i would want the maximum speed at which highest str can be maintained to be high as possible to get combat advantage vs same str but slow speed turners like say a warthog

As speed gets past this point the str will fall off and at mach3 the turn rates will be very low at highest speed of a foxhound

[shiv]

>> But lower is better.

Did not get this part, i would want the maximum speed at which highest str can be maintained to be high as possible to get combat advantage vs same str but slow speed turners like say a warthog

As speed gets past this point the str will fall off and at mach3 the turn rates will be very low at highest speed of a foxhound

I believe it is like this. It's a little weird and non-intuitive

In a turn the wing+body+tail lift has 2 component orthogonal vectors. One is causing the plane to turn (let me call it turn vector) and the other is maintaining the altitude (lift vector) . For a higher rate of turn the bank angle has to be higher and this reduces the lift vector. But if the lift vector tails off and the plane will start doing a side-slip. To avoid this this the speed will have to be higher in order to increase the vertical (lift) vector to maintain altitude. This in turn will massively increase the turning vector (G-force). The G forces are dependent on the bank angle (as in the chart I posted earlier). If the speed is higher the G-forces are higher. Sustained 7-8G or higher will make most humans unconscious and even higher G forces can cause structural damage.

So in theory - if your plane can generate enough lift (using wing, body and other surfaces including tail) to retain altitude with no side slip while doing as tight a turn as possible, the lowest speed at which the tightest turn can be done is best. Any faster then either the G-forces become too high or the turn rate is reduced (the turning vector is reduced)

In the B-52 crash video below the plane maintains altitude till 35 seconds when its bank angle is about 45 degrees. 2 seconds later it is clear that it is side-slipping and the bank angle is too high - there is not enough lift to keep it in the air. The pilot straightens up but by 47 sec he is again in a bank that is unrecoverable for that altitude.
https://www.youtube.com/watch?v=7-S_NM--evM


In the J-20 video linked below the pilots starts his banking turn at 38 seconds andby 42 seconds the pilot is going nose down because he cannot hold the altitude at that bank angle.
https://youtu.be/MwdFZ8xFUjU?t=38

[KBDagha]

LCA Tejas SP-9 successfully completes first flight
24th March 2018

LCA Tejas SP-9 (LA-5009) successfully flew for the first time today taking off at 1033 hrs from HAL Airport in Bengaluru and landing back at 1054 hrs. SP-9 flew for 21 mins with Air. Cmde KA Muthanna (Retd) in the cockpit. This is the Ninth Series Production Aircraft and will be handed over to the No.45 Squadron of the Indian Air Force also called the 'Flying Daggers' after a few production sorties
Photo for representational purposes only.
#LCATejas #SeriesProduction #FlyingDaggers45 #IAF #HAL #ADA

[suryag]

Today being Saturday as soon as I heard the Tejas roar I ran out expecting to see SP9(SP8 flew on Saturday too ), saw a Tejas but couldn’t make out if it was SP9, this news made my day. IR sir any more expected in near future(end of April) or we would have to wait longer for SP10? Rangachari sir and his boys might be super excited with these numbers and hopefully are honing their tactics to kick foreign butts in the next exercise, they should also be packing their bags to relocate to thanjavur.

These SPs should become like all naarmal PSLV launches, next big event am waiting for is wet refueling by a tanker in air

BTW am eagerly looking forward for a pic with all 9 lined up in tarmac

Overall very happy today

[Singha]

Do the high power wing blowers and huge flaps of the c17 types help to avoid or delay the fatal problem the b52 fell into?
I hv seen some footage where the c17 seemed to hang nearly stationary in the air but in level flight not turning

[fanne]

Flying daggers now have 9 planes. My guess it after 10-11 planes total, the next SQ (no 18?) will start receiving planes. I have been one crying about the slow rate of production. I hope, next fiscal they produce the max that is possible (16?) and not fall short. Their are many roadblocks in achieving max production - Lots of external players, some outside the country (engines, radars). It needs a different level of planning, HAL has never done this. At most it had produced planes from one vendor, all in house, mostly SKD or fully KD kits. MKI had some multiple player, still most of the plane is not from raw material stage. This year itself, HAL could have produced more from it installed capacity, but has not.

[Rakesh]

LCA Tejas SP-9 successfully completes first flight
24th March 2018

LCA Tejas SP-9 (LA-5009) successfully flew for the first time today taking off at 1033 hrs from HAL Airport in Bengaluru and landing back at 1054 hrs. SP-9 flew for 21 mins with Air. Cmde KA Muthanna (Retd) in the cockpit. This is the Ninth Series Production Aircraft and will be handed over to the No.45 Squadron of the Indian Air Force also called the 'Flying Daggers' after a few production sorties
Photo for representational purposes only.
#LCATejas #SeriesProduction #FlyingDaggers45 #IAF #HAL #ADA

Very nice for a beautiful Saturday morning! Page 1 of this thread updated. Can someone advise which line?

[Rakesh]

It certainly looks like Tejas production is on the upswing. 2019 is the big Kahuna --> 16/year.

- Oct 2014 - one aircraft
- July 2016 - No 45 Sqn reserructed with Tejas with SP-1 and SP-2
- 2016 saw a third bird being added to the squadron
- 2017 saw three more birds joining the squadron, so sqn strenth was then at six birds
- 2018 so far, has seen three birds joining the squadron and sqn strength is now at nine birds.
- March 31 is the end of the fiscal year and nine more months left for 2018. So hoping for another 3 - 4 more by 2018 end.

[suryag]

Rakesh sir please don’t open that confusing “which line” question

[chetak]

>> But lower is better.

Did not get this part, i would want the maximum speed at which highest str can be maintained to be high as possible to get combat advantage vs same str but slow speed turners like say a warthog

As speed gets past this point the str will fall off and at mach3 the turn rates will be very low at highest speed of a foxhound

Just saying onlee.

has/have any other cause(s) been considered??

Sometimes pilots do really crazy things.

know of one incident when an Indian pilot, during the practice, prior to a display for a dignitary, took his aircraft into the ground, along with his copilot.

The really tight turn, and that too, in a B 52, and so close to the ground, seems like a mistake that even a rookie pilot would not do.

[chetak]

>> But lower is better.

Did not get this part, i would want the maximum speed at which highest str can be maintained to be high as possible to get combat advantage vs same str but slow speed turners like say a warthog

As speed gets past this point the str will fall off and at mach3 the turn rates will be very low at highest speed of a foxhound

I believe it is like this. It's a little weird and non-intuitive

In a turn the wing+body+tail lift has 2 component orthogonal vectors. One is causing the plane to turn (let me call it turn vector) and the other is maintaining the altitude (lift vector) . For a higher rate of turn the bank angle has to be higher and this reduces the lift vector. But if the lift vector tails off and the plane will start doing a side-slip. To avoid this this the speed will have to be higher in order to increase the vertical (lift) vector to maintain altitude. This in turn will massively increase the turning vector (G-force). The G forces are dependent on the bank angle (as in the chart I posted earlier). If the speed is higher the G-forces are higher. Sustained 7-8G or higher will make most humans unconscious and even higher G forces can cause structural damage.

So in theory - if your plane can generate enough lift (using wing, body and other surfaces including tail) to retain altitude with no side slip while doing as tight a turn as possible, the lowest speed at which the tightest turn can be done is best. Any faster then either the G-forces become too high or the turn rate is reduced (the turning vector is reduced)

In the B-52 crash video below the plane maintains altitude till 35 seconds when its bank angle is about 45 degrees. 2 seconds later it is clear that it is side-slipping and the bank angle is too high - there is not enough lift to keep it in the air. The pilot straightens up but by 47 sec he is again in a bank that is unrecoverable for that altitude.
https://www.youtube.com/watch?v=7-S_NM--evM


In the J-20 video linked below the pilots starts his banking turn at 38 seconds andby 42 seconds the pilot is going nose down because he cannot hold the altitude at that bank angle.
https://youtu.be/MwdFZ8xFUjU?t=38

Lots of pilots, by virtue of experience and repeated exposure, can hold sustained high G turns for relatively long periods.

B52 pilots, by virtue of their mission profiles with nuke payloads would train long and hard for high G manoeuvers. Also, these guys routinely fly in G suits.

That said, +Gs are much easier to manage than -Gs.

[shiv]

Lots of pilots, by virtue of experience and repeated exposure, can hold sustained high G turns for relatively long periods.

B52 pilots, by virtue of their mission profiles with nuke payloads would train long and hard for high G manoeuvers.

That said, +Gs are much easier to manage than -Gs.

Several issues here:
1. That B-52 started sideslipping and losing altitude at 45 degrees which corresponds to 1.5G. So whether a pilot can withstand it or not - if the plane starts descending, only adequate altitude can save it.

2. Lots of pilots have been past +8G - but no matter how tough and macho one may consider oneself to be it is physically demanding and there can be brief loss of attention simply because this is a mechanical question of liquid blood flowing through tubes in the brain with a normal heart trying to push the blood into the brain while the blood suddenly requires 8x or 9x the pressure which the heart simply cannot deliver. That aside those "pipes" are elastic so some pipes will swell while more distant pipes near the brain surface will lose blood supply briefly.

3. If the wings are loaded with stores then it may not be able to exceed 4 G - because a 500 kb bomb becomes 2000 kg in a 75 degree bank/4G turn. Or the wing/pylon will get ripped off

As regards the B-52, it is well documented that it was a macho pilot error
https://en.wikipedia.org/wiki/1994_Fair ... B-52_crash

The accident board stated that Colonel Holland's macho, daredevil personality significantly influenced the crash sequence. USAF personnel testified that Holland had developed a reputation as an aggressive pilot who often broke flight-safety and other rules. The rule-breaking included flying below minimum-clearance altitudes and exceeding bank-angle limitations and climb rates.[10]

[shiv]

Do the high power wing blowers and huge flaps of the c17 types help to avoid or delay the fatal problem the b52 fell into?
I hv seen some footage where the c17 seemed to hang nearly stationary in the air but in level flight not turning

Those blowers will help only in level flight.

[chetak]

Lots of pilots, by virtue of experience and repeated exposure, can hold sustained high G turns for relatively long periods.

B52 pilots, by virtue of their mission profiles with nuke payloads would train long and hard for high G manoeuvers.

That said, +Gs are much easier to manage than -Gs.

Several issues here:
1. That B-52 started sideslipping and losing altitude at 45 degrees which corresponds to 1.5G. So whether a pilot can withstand it or not - if the plane starts descending, only adequate altitude can save it.

2. Lots of pilots have been past +8G - but no matter how tough and macho one may consider oneself to be it is physically demanding and there can be brief loss of attention simply because this is a mechanical question of liquid blood flowing through tubes in the brain with a normal heart trying to push the blood into the brain while the blood suddenly requires 8x or 9x the pressure which the heart simply cannot deliver. That aside those "pipes" are elastic so some pipes will swell while more distant pipes near the brain surface will lose blood supply briefly.

3. If the wings are loaded with stores then it may not be able to exceed 4 G - because a 500 kb bomb becomes 2000 kg in a 75 degree bank/4G turn. Or the wing/pylon will get ripped off

As regards the B-52, it is well documented that it was a macho pilot error
https://en.wikipedia.org/wiki/1994_Fair ... B-52_crash

The accident board stated that Colonel Holland's macho, daredevil personality significantly influenced the crash sequence. USAF personnel testified that Holland had developed a reputation as an aggressive pilot who often broke flight-safety and other rules. The rule-breaking included flying below minimum-clearance altitudes and exceeding bank-angle limitations and climb rates.[10]

Yes, there were other causes.

The guy was an idiot and he took his crew with him.

[Rakesh]

Rakesh sir please don’t open that confusing “which line” question

Surya Saar, I need to update page 1 of this dhaaga. That is why Sorry!

[Indranil]

>> But lower is better.

Did not get this part, i would want the maximum speed at which highest str can be maintained to be high as possible to get combat advantage vs same str but slow speed turners like say a warthog

As speed gets past this point the str will fall off and at mach3 the turn rates will be very low at highest speed of a foxhound

​Two different things Singha sir​.

Gs is nothing but a measure of acceleration. If two aircrafts are pulling the same Gs, the plane flying slower is making the tighter turn.

Energy management is related and but not he same thing. Imagine that you and your adversary get into a turning fight. You both are flying much faster than your corner speeds at the merge. Therefore, both of you can turn faster than your respective STRs. If you lose energy at a slower rate, you will be able to keep turning at this faster rate for longer. Similarly, if your corner speed is lower, you can keep turning at this faster rate for longer. Second, if you lose energy at a lower rate, your engine can push you at a faster speed. If you can cut your turn radius, you can increase your rate of turn. If you can't, you will have higher energy while turning at the same rate.

[JTull]

LCA Tejas SP-9 successfully completes first flight
24th March 2018

LCA Tejas SP-9 (LA-5009) successfully flew for the first time today taking off at 1033 hrs from HAL Airport in Bengaluru and landing back at 1054 hrs. SP-9 flew for 21 mins with Air. Cmde KA Muthanna (Retd) in the cockpit. This is the Ninth Series Production Aircraft and will be handed over to the No.45 Squadron of the Indian Air Force also called the 'Flying Daggers' after a few production sorties
Photo for representational purposes only.
#LCATejas #SeriesProduction #FlyingDaggers45 #IAF #HAL #ADA

Yaaawwnn!

Waiting for the day when the only way to know the number delivered is when we hear about a new sqn being raised or by trolling thru some annual reports.

Next sqn should be announced later this year if we're expecting 12 deliveries next fiscal.

[Neshant]

Looking back at this program, what could have been done differently from planning, design or production perspective?

[vipins]

Rakesh sir please don’t open that confusing “which line” question

Surya Saar, I need to update page 1 of this dhaaga. That is why Sorry!

Line 1 as per one of the post by Indranil saar!!
Link

[ramana]

Kersi ADEN has slower rate of fire and each round is heavier. As it is I think GSh was restricted to maybe 120 rounds (not sure)

Another way of saying is the GSh 23 with twin barrels in one location has higher rate of fire and occupies less space on Tejas.

For comparison one can compare the kinetic energy of a 30mm NATO round and 23 mm GSh round. Add rate of fire and an increment for explosive energy and compare the gun stations.
Will do it this weekend.
That way we bring facts to table.

Ok. Considering the muzzle velocity, the bullet weight, the explosive contribution, and the rate of fire the 23 GSh beats the 30 mm DEFA or Aden in total destructive power.

I think is air to air this trumps the other cannon.
Ground attack maybe different gun.

So the Tejas choice is the best feasible cannon for IAF.

I will link the site which explains all this and compares many cannon.

[Indranil]

Rakesh,

It is from Line 1, but let us leave out this bit of the detail moving on.

Chetak sir,

You are absolutely right about how trained pilots and stupid pilots make a plane great or bad. There are so many instances from the Vietnam war etc. where the Yankee pilots could not believe what some of the Vietnamese were doing with the Mig-21s. Some flew straight into the hairs and others did things which startled the pilots.

Modern fighters though have a lot of aids. Tejas, like the Eurocanards, takes control over the plane recovers and hands it back to the pilot. Last year they were testing this autorecovery and seeing how slow can the Tejas fly. They found out that they were actually conservative. So they made changes to the flight computer to allow flying at even lower speeds. Both those speeds are much lower than what has been demonstrated in public.

[SaiK]

https://twitter.com/writetake/status/977775663900954624

[srin]

Another way of saying is the GSh 23 with twin barrels in one location has higher rate of fire and occupies less space on Tejas.

For comparison one can compare the kinetic energy of a 30mm NATO round and 23 mm GSh round. Add rate of fire and an increment for explosive energy and compare the gun stations.
Will do it this weekend.
That way we bring facts to table.

Ok. Considering the muzzle velocity, the bullet weight, the explosive contribution, and the rate of fire the 23 GSh beats the 30 mm DEFA or Aden in total destructive power.

I think is air to air this trumps the other cannon.
Ground attack maybe different gun.

So the Tejas choice is the best feasible cannon for IAF.

I will link the site which explains all this and compares many cannon.

Can please post the link ? Would love to understand this better.

[ramana]

I was going to do a summary with the link. Its quite late now.
Please do the honors. Here is the link.


http://quarryhs.co.uk/modern_fighter_gu ... veness.htm

[Karthik S]

Tejas FB confirmed the envelope for MK1A - 15Km ceiling, 24deg AoA and certified for 8G loads

In the numerous anecdotes one reads about older aircraft - one finds that they too were "certified" to x G and it was up to the pilots to make sure that they (manually/voluntarily) did not exceed that. From this fact emerge the exciting tales of pilots who exceeded the G limits either to escape a tricky situation or something else. I recently read a story (may have been HF 24???) in which on a challenge - a pilot pulled such high G that one of the pylons tore off and the G meter was stuck at max. Of course we will never hear the stories of people who did excess high G and either lost control (lost consciousness or a wing

In a plane like the Tejas "certified for 8 G" means that the FBW software will not allow the plane to exceed 8G until some future date when they may increase that

I read a similar story about a pilot pulling off similar very high G stunt ( > 9G) on MiG 29 IIRC but after which the plane was written off something like that.

[Karthik S]

Kersi ADEN has slower rate of fire and each round is heavier. As it is I think GSh was restricted to maybe 120 rounds (not sure)

Had this query, I watched almost all episodes of Dogfights series in the History channel. Observed that the Israelis relied and were excellent with cannons as they didn't have access to missiles tech back in 60s and 70s. But in current scenario, with such advanced A to A missiles and maneuverable planes, will cannon really play a difference. If we think about it, those cannons fire at thousands of rounds per minute, so the ammo carried by planes can be used for just 1 burst, if the pilot squeezes the trigger for 2-3 seconds, ammo is gone. But considering the weight, vibration variables, is it really necessary to carry one.

[Trikaal]

That final stick of misinformation that Tejas can't produced quickly enough in desh has to be broken.

This is a great news. The last major issue that remains is a sanctions proof and reliable engine. Only way it can happen is by having a domestic engine.


404 / 414 are interim solutions. We need Kaveri to be on full stream.

hopefully kaveri will be ready in time to be tested on Mk2. We have 7-9 years before Mk2 will be inducted so should be enough time for Kaveri development.

[hanumadu]

Saurav Jha
‏

@SJha1618
12m12 minutes ago
More
Based on my discussions with people in the 'Tejas community' it seems increasingly likely that MK-1A production may begin with the 21st HAL series production unit itself.

What about testing? Will it be done by the time first 20 are delivered?

[Thakur_B]

^^ I have a growing suspicion that Mk1A will come with Uttam as no deal has been announced for radar for Mk1A.

Rest pretty much everything is Mk1A only.

[fanne]

A aircraft borne radar is only as good as the missiles it fires, what does Uttam has?

[Pratyush]

A aircraft borne radar is only as good as the missiles it fires, what does Uttam has?

Astra.

[fanne]

Not proven enough yet!! CCM is not a problem as it is not that dependent on radar (most are IR based). Though some are slaved to the radar as well. For medium to longer range you need a family of missiles, radar based, it based guided by radar for mid course, a combination of radar and IR. Various ranges. You need at least 3-4 variant proven. Astra for us is a great start, but maybe few years from fielding. We need a proven combo - Israel or france

[srin]

I don't understand - are you saying that if we have our own radar, then Israelis won't allow interfacing Derby with our radar ? Is so, why would they interface with a French radar ?
Aren't there any open standards for radars and missiles to interface with each other and with the aircraft ?

[Pratyush]

Not proven enough yet!! CCM is not a problem as it is not that dependent on radar (most are IR based). Though some are slaved to the radar as well. For medium to longer range you need a family of missiles, radar based, it based guided by radar for mid course, a combination of radar and IR. Various ranges. You need at least 3-4 variant proven. Astra for us is a great start, but maybe few years from fielding. We need a proven combo - Israel or france

The astra is good enough for su30 but it's not good enough for the Tejas. Also how do you prove any weapon. If astra is not proven. Then by that logic, other than Amram no other missile is proven. As it has been fired in combat.

[John]

^^ I have a growing suspicion that Mk1A will come with Uttam as no deal has been announced for radar for Mk1A.

Rest pretty much everything is Mk1A only.

Has list of features in Mk.1A been confirmed? Apart from what was mentioned in Shiv Aroor article? He only mentions a few.

[John]

I don't understand - are you saying that if we have our own radar, then Israelis won't allow interfacing Derby with our radar ? Is so, why would they interface with a French radar ?
Aren't there any open standards for radars and missiles to interface with each other and with the aircraft ?

I don't understand what he is saying either; Rafael has shown to be more than willing to integrate with domestic or Russian radar even when IAI equipments ( they are two different companies though they are gov owned) are not used. We are seeing that with Barak-1 and Barak-8 right now.

[shiv]

Kersi ADEN has slower rate of fire and each round is heavier. As it is I think GSh was restricted to maybe 120 rounds (not sure)

Had this query, I watched almost all episodes of Dogfights series in the History channel. Observed that the Israelis relied and were excellent with cannons as they didn't have access to missiles tech back in 60s and 70s. But in current scenario, with such advanced A to A missiles and maneuverable planes, will cannon really play a difference. If we think about it, those cannons fire at thousands of rounds per minute, so the ammo carried by planes can be used for just 1 burst, if the pilot squeezes the trigger for 2-3 seconds, ammo is gone. But considering the weight, vibration variables, is it really necessary to carry one.

This subject was debated in the US after Vietnam by which time they expected missile to do the job - but found that guns were needed. Guns were re-introduced into US fighters. Later, the IAF - starting 1965 found that MiG 21 missiles were not working and demanded guns for the MiG 21. By 1971 - most air to air kills were with guns. That said India lost more aircraft to anti-aircraft fire attacking targets than to Paki interception

Modern fighters barely carry 2-3 seconds of ammunition - but in air to air it would be rare for a turning twisting enemy aircraft to offer himself to be shot for more than a fraction of a second. These cannon shoot a cloud of shells in a short while and one shell can achieve a kill. A half second burst sends a cloud of 30 shells at the target. But all in all guns still have their uses although missiles are getting better.

[Indranil]

Integration of weapons with Uttam is not the challenge. Uttam's hardware realization is complete. However, it has to be calibrated and fine tuned for all modes in all situations. That will take time, but should be taken up immediately. We are speaking of years because you have to take to the air, complete the test flight, come back, modify and get back in the air again.

HAL is therefore pushing back on Uttam in Mk1A. DRDO is pushing strongly for it. It helps that Dr. Christopher was directly linked with the project.

IMHO, Uttam should be delinked from Mk1A. After FOC of Mk1, all LSPs should be made available for testing Uttam. Mk2 should come with Uttams.

[Suresh S]

This issue about whether modern Aircraft needs guns or not is like arguing whether in this era of endovascular and laparoscopic surgery open surgery is required or not. The answer as we know is absolutely yes.

[srin]

I was going to do a summary with the link. Its quite late now.
Please do the honors. Here is the link.


http://quarryhs.co.uk/modern_fighter_gu ... veness.htm

Thank you, Ramana. Let me take a look at it. But would love to see your views as well.