MRCA Discussion - October 2, 2010

[shukla]

More juice..

UK to push India on Typhoon

The government is doing "all it can" to encourage India to purchase Typhoon aircraft, defence minister Gerald Howarth has said. Howarth, who has responsibility for defence exports, told the Commons that he agreed the Typhoon had "overwhelming" technical superiority, a view he noted The Sunday Telegraph had reported to have been reached by the Indian government.

He said: "We are doing all we can in conjunction with our partner nations to secure that order." Howarth said that Germany has been taking the lead in selling Typhoon to India. But he said that the UK would also get involved. He said: "I am very hopeful that when my right hon. friend the Secretary of State for Defence visits India, we can further promote the case of the Typhoon."

[Tummen]

7200kg is the SAAB's official figure for Gripen NG's payload.
http://www.saabgroup.com/en/Air/Gripen- ... Gripen-IN/

Gaur, that is just clever marketing, the Gripen NG's payload remains around 6 tonnes. The 7.2 tonne figure they use would be achievable only after a compromise on internal fuel. IOWs, the Gripen NG at 7000kg (empty) + 3400kg (internal fuel max - 40% increase over C version) + 6000kg (external payload) ~ 16.5 tonnes (MTOW). There is simply no way that payload can be 7200kg unless it suddenly dropped 1 tonne empty weight!

So what they do in that brochure is simply show figures without full internal fuel load, which is misleading and allows one to compare it to larger MRCA birds such as the EF-2000. In the case of the Typhoon, the weights clearly show this:

11200kg (empty)
5000kg (max internal fuel)
7500kg (max payload)
Total: 24000kg (MTOW)

Here there is no compromise on internal fuel to achieve the 7.5 ton payload (unlike the Gripen) so the comparison is rather clever but quite flawed. IOWs, the Gripen NG, although very impressive, does not fall anywhere close to the twin engined a/c capacities, and there is little to doubt that the Tiffy could carry more if further optimized.

CM

I am not sure we have the correct numbers on SAABs goal on Gripens INs empty weight (7000kg). Any producer of military aircraft might find it convenient to not openly reveal the capabilities of its system. SAAB have admitted in interviews that the correct empty weigth of Gripen is less than the official number. Here are some numbers, I can not guarantee they are correct, but I am sure readers can make up their own opinion.

At SAAB homepage
the singleseat “Gripen A” emptyweight is said to be 6700 kg
the singleseat “Gripen C” emptyweight is said to be 6800 kg, double seat “Gripen D” 7100kg
the singleseat “Gripen IN” emptyweigth is stated to become 7000 kg or 200 kg more than Gripen C.

However at the homepage for Ministry of Defence & Armed Forces of the Czech Republic (they operate Gripen A/B) the following numbers appear :

Technical specifications of JAS-39 A/B Gripen
Wing Span - 8,40 m
Length - 14.10 m (14.80 m two-seat version)
Height - 4.70 m

Empty Weight - 5,670 kg
Maximum Take-off Weight - 13,000 kg
Maximum Armament Payload - 4,200 kg
External Tanks Capacity - 2,400 l
Minimum RWY Area - 800 x 14 m
Maximum G-load Factor- +9 g / -4 g

Powerplant - 1x Volvo Aero RM 12
Maximum Thrust - 54 kN
Maximum Thrust With Afterburner - 80.5 kN

Maximum Speed at High Level - 2,130 km/h
Maximum Speed at Sea Level - 1,225 km/h
Range Radius (2,000 kg payload) - 700 km
http://www.army.cz/scripts/detail.php?id=6100

Se it seem possible Prof. Prodyut Das used these numbers (5670kg) when he stated that Gripens empty weigth is 5700 kg. These numbers could be correct, we just do not know.
http://www.scribd.com/doc/39718239/VAYU ... -LCA-Tejas

Gripen C on the other hand could according to this logic be some 30 kg heavier than Gripen A, or weigth 5700 kg (5670+30).

If these numbers are the correct ones (and they are from open sources) it could be that the aim of Gripen IN is to weigth 5700+200 kg empty.

In this case SAABs calculations about how much Gripen NG can carry is correct.
5900kg (empty) + 3400kg (internal fuel max - 40% increase over C version) + 7200kg (external payload) ~ 16.5 tonnes (MTOW).

Also, I have this speculation that the maximum (if not sustained) g-limit with full load does not have to decrease so much compared to Gripen C, if the added weigth is carried on the wing, since it is the wing itself and not the body that will have to lift that weight.

Also, the T/W of Gripen will become about the same as Eurofighter with typical Loaded weight (50% internal fuel, AA-missiles).

EJ200 is said to Have 30% growth potential, from 90Kn to 117Kn-120Kn.
http://en.wikipedia.org/wiki/Eurojet_EJ200

F414 is said to have 20% growth potential, from 98Kn to 117Kn
http://en.wikipedia.org/wiki/General_Electric_F414

So, it seem Gripen NG have almost same potential to improve T/W as Eurofighter.

Yes, obviously I am a Gripen fanboy, but I am not sure Gripen is the best aircraft for India. There are too many unknowns.
In the end I think India will buy american, F18 E/F.

Please do point out any mistakes above!

[Indranil]

Also, I have this speculation that the maximum (if not sustained) g-limit with full load does not have to decrease so much compared to Gripen C, if the added weigth is carried on the wing, since it is the wing itself and not the body that will have to lift that weight.

This is not true Wherever you decide to sling the weapons, that part has to be fortified to bear the weight X g-load X max tolerance. If you slung it from the body, you would have to strengthen the body and the wing join. If you sling it from the wing, You will have to strengthen the wing. A heavier wing will require a better join .

Believe whatever figures you choose to believe, but be rest assured that a company trying to advertise its plane and its capabilities, they will never over-quote its weight.

However the Gripen would have definitely cost us less to maintain. Even if I disregard what the Swedes have been saying all along that their planes were designed to be more servicable, and consider that all the planes have same serviceability, we would only spend half the price for fuel, engine replacement, and all the paraphernalia around the engines. Incidentally that would not be a small chunk of the operating costs. Am I missing something?

[Indranil]

Supposed you were to make a 180 degree turn. Do you think the Su-30 would be able to just turn like that because he has TV. He would be able to go to extreme AoA making his whole body act as brake which will slow him down very fast. He can follow this up with a sharp hammerhead, or Immelmann or Split-S to turn 180 degrees. Having TVC gives him control all throughout this "post stall" maneuvers, which essentially mean AoA or air speeds where other plains would have lost authority. However, there is a flip side to this, Coming out of the turn the Su-30 has almost no velocity. So this is not as simple as it sounds.

Lets say there are two aircrafts, A and B, such that A has TVC (Flanker?) and is more maneuverable than B (Typhoon?), and B (no TVC) is more agile than A.

Which of the two aircraft, armed with radars and missiles of similar range and effectiveness, is more likely to win a BVR contest? What about a WVR engagement?

My friend if that could be answered with any authority you would have either seen all planes with TVC or none with them. Also the answer to your question can not be given without a complete description of the arena and the velocity vectors of the planes.

I don't see the use of TVC in BVR. However I would love to learn more here.

But in WVR TVC has been proven to provide more survivability. Notice that a TVC plane can do all that a non-TVC plane can do, but the reverse is not true. However, earlier TVC used to come with tremendous weight penalties and hence the advantages in manoeuvrability would be mitigated by loss in agility. However, with what the Spanish have come out on the EJ-200 will be a game changer IMHO.

45 kg for one engine and 90 kg for two engines will certainly tilt the tables for the TVC. I believe you will start seeing most of the new designs (multirole and A2A fighters) roll out with TVC.

JMT

[Kronop]

Also, I have this speculation that the maximum (if not sustained) g-limit with full load does not have to decrease so much compared to Gripen C, if the added weigth is carried on the wing, since it is the wing itself and not the body that will have to lift that weight.

This is not true Wherever you decide to sling the weapons, that part has to be fortified to bear the weight X g-load X max tolerance. If you slung it from the body, you would have to strengthen the body and the wing join. If you sling it from the wing, You will have to strengthen the wing. A heavier wing will require a better join .

Believe whatever figures you choose to believe, but be rest assured that a company trying to advertise it's plane and its capabilities will never over-quote its weight.

However the Gripen would have definitely cost us less to maintain. Even if I disregard what the Swedes have been saying all along that their planes were designed to be more servicable, and consider that all the planes have same serviceability, we would only spend half the price for fuel, engine replacement, and all the paraphernalia around the engines. Incidentally that would not be a small chunk of the operating costs. Am I missing something?

Indranilroy is absolutely correct on the loads.
Normaly heavy load alternatives carried on the wings comes with limitations on peak and sustained g-loads from a structural standpoint. It is also often the case that such limitations are not directly contirbuted to reaching the design limit load but instead are based on fatigue/life considerations from a load spectrum point of view.

In war-time operation, when a relatively short lifespan of the airframe is expected anyway, such g-load limitations could be removed or relaxed.

[Indranil]

Don't know where to ask this ... but since we are on this topic.

I know that the missiles are shaped like the von Kármán ogive and the external fuel tanks are shaped like the Sears–Haack body to reduce wave drag. However there is no lift generation.

Now could the tanks be shaped in the shape of a aerofoil to provide enough lift for its weight? Also could the missiles be provided in a housing which provides lift for the weight of the housing and the missile it houses. When a missile is to be fired, the housing is opened, the missile drops down and then fires. or the missille drops with the housing and housing peels off before the missile fires.

The advantage of design is
1. The agility, manoeuvrability of the plane is only hampered by the ratio of loss of TWR and not because of lift/weight ratio. Imagine the advantages the radius of loop of a loaded plane will be similar to that of a clean plane. Albeit the drag increased drag would hamper it to some extent.
2. The housing can be made VLO in shape and thus the compromise of stealth on externally loaded weapons/fuel tanks will be a thing of the past.
3. Your plane doesn't have be strengthened as much because the load of the weapons are partially is shared by the lift generated by the housing. Hence we would have lighter plane to start with. Or one could increase the max payload.

This is idea is somewhat used for the CFTs of the SUFA and also int he enclosed weapons pod for the road map ahead for the F-18.

I am not asking for the CFTs to be added to the fuselage. Just shape the tanks and the enclosing weapons pod to be more stealthy and lift producing.

There must be a strong reason for not doing this. Could somebody identify it for me?

[nikhil_p]

^^^
One reason could be the effect of airflow turbulence created by this and the other necessary control surfaces which will need to be created to avoid this.
An example would be to consider a tank designed as a wing, would create a mini vortex at the trailing edge, creating a low pressure area below the wing, which is certainly not desirable.

[Indranil]

^^^ Thats a valid point.

But then this vortex will be caused at the trailing edge of the surface for a housing for the missile or the tank, that is almost at the end of the wing . All missiles have winglets. Even modern external tanks have them. They must be creating vortices as well. Doesn't seem to affect the lift of the planes wing.
That can probably be explained that the vortices are formed below and almost near the trailing edge of the wing and hence the vortices are created behind the plane rather than under it.

Consider the Kh-31A Missile. What about the vortices created by it's front fins?
Also if this is not a problem, the vortices underneath a wing should not be a problem .

[Cain Marko]

Indeed. Clever marketing and if one just verifies the data it becomes clear that there will be severe limitations on maneuverability with such huge payloads on a small fighter. After all, the plain airframe structure weight itself will be only around ~6000 kgs (rest will be fuel tanks empty weights, various avionics boxes and radar, ejection seat, pipes, internally retracting fuel probe, etc.). it can only carry so much stress without being damaged and the FCS will not allow that.....It is impressive nonetheless for such a small fighter, but in reality the Typhoon or Rafale or even the MiG-35 might be able to take such heavy payloads and still offer slightly more maneuverability since the airframe itself may not be so overstressed by pulling high g's with 6 tons of payload + 3 tons of internal fuel. Given that their empty weight will consist of at least 1.3 tons due to an extra engine and associated strengthening, they still have more bulk and strength in their airframes. For instance, the Rafale has an empty weight of 10.3 tons and if 2.3 tons is due to the M-88-2 engines and 1200 kgs for the rest, then that leaves an empty bare airframe weight of 6800 kgs and that is around 800 kgs more than the Gripen NG's bare airframe weight. Much of that weight will be centered around the wing box, fittings near the fin base, hardpoints, etc. and these will allow a little higher amount of gs to be pulled. For instance the Rafale can pull 5.5g/20° when the FCS is configured to the air-to-ground mode.

I feel that the Gripen NG is now squarely in Mirage 2000 category, albeit a wee bit lighter, of course the far superior F-414 engine also helps considerably vis a vis the vintage 2000. However, I simply don't see why the Tejas Mk2 won't allow for similar capability; it is this reason imho, that the Gripen NG is a bit redundant for the MRCA requirement.

There is little doubt that the Gripen will strain to achieve the 6000kg payload parameter (as will the others in attempting their respective mtows), but I don't see this being such a big deal for an EF or Rafale or MIG.

Other than that, this little bird seems to offer quite a lot.

It reportedly enhances survivability by 20 to 30 percent.

This was further corroborated with the F-16VISTA program as well! To think about it, why would the IAF go for the TVC if its benefits were so marginal? It does come with extra maintenance headaches afterall. Not to mention the weight savings to be had without the TVC. Surely, those level headed chaps were not enamoured by Cobra type manouvers? (which btw, could be done by on tvc a/c as well).

Further, iirc, there was a manouver, whereby a/c would use low speed and fly at certain angles to emitting sensors to avoid detection (doppler notching?) - this was a fairly useful move to spoof modern FCRs - I believe tvc would help here too - don't we hear of the russkis boasting that the bird can almost hover like a helicopter?

Another factor to consider is the fact that IAF/PAF/PLAAF bases are located fairly close to each other, the time to engage BVR might simply not exist in certain scenarios, which might boil down to WVR games. Here again the massive Rambha might benefit with TVC - iirc GJ mentioning that some jocks felt that the TVC+HMS combo made the Rambha unbeatable, and they were flying against topnotch fulcrums!

CM

[ramana]

Recall only a few years back US was at forefront of those screaming arms race when ever India bought a few shotguns!

[Gaur]

I unfortunately had little time to follow the discussion for the last couple of days. So, forgive me if I am completely off the tangent here regarding the reason for which members are discussing TVC. However, let me give my 2 cents.

I do not know how the discussion regarding TVC came into focus in MMRCA thread but TVC's effectiveness should not be gauged by F-16 VISTA program. Installation of TVC nozzles in F-16 had resulted in around 650 kg
(including the weight of ballast, hydraulics, landing gear etc) weight increase. So, General Dynamics concluded that it is not worth for a small fighter like F-16. But the effect of TVC on a heavy fighters like MKI, F-22 and PAK-FA should be tremendous. This can be clearly concluded from from numerous western studies and simulations.

Some results:

Herbst: 5:1 in favour of TVC a/c against same a/c without TVC.

US German X-31 vs F-18: 5:1 for dogfights. 32:1 with guns only. This is a tremendous achievement considering the weight of X-31.

The famous USAF commissioned Being Study: MKI vs F-15C. MKI wins "every time".

There are many more studies but I am sure most of the members would know about them. Of course, TVC has been a subject of fierce debate with both sides having valid arguments. Opponents of TVC say that the loss in energy after performing post stall maneuvers would negate any advantage that TVC allegedly provides. That it has no effect on turn rate (My answer: Where is it written that it is meant to?). Not to mention that the studies are just a ploy to either sell or buy depending upon who is doing the studies/simulations.

My POV regarding this is that TVC is a highly useful tool. And like all tools there are places to use it and places not to. TVC provides better post stall control, better pitch control and higher AOA and it should be used considering that in mind. If you are doing tailslide against an IR missile, then only you are to be blame when you are blown to smithereens. However, if you have a enemy fighter on your tail, loss of energy may be the only thing that may save you.

High AOA is one of the most focused attribute of a fighter a/c. Every designers strives to extract max AOA from the design and every pilot wants more. So, in a world which emphasizes so much upon the importance of high AOA, the limitless AOA provided by TVC surely cannot be underestimated.

[Cain Marko]

I do not know how the discussion regarding TVC came into focus in MMRCA thread but TVC's effectiveness should not be gauged by F-16 VISTA program. Installation of TVC nozzles in F-16 had resulted in around 650 kg
(including the weight of ballast, hydraulics, landing gear etc) weight increase. So, General Dynamics concluded that it is not worth for a small fighter like F-16.

However, the bottomline here, in the context of our discussion is performance, and iirc, the VISTA/MATV was tested against uber f-16s/18s etc, and had favourable results -

Phase III of the MATV program was a tactical demonstration consisting of 183 one-versus-one and one-versus-two fighter engagements against F-16, F-15, and F-18 fighters. The general results: When the F-16 MATV started from an offensive position in a one-on-one encounter, thrust vectoring reduced the time for the first-shot opportunity and reduced the effect of common mistakes such as overshooting and getting "stuck in lag," where the aircraft can't quite get its nose onto the opponent due to AOA limits. Defensively, vectoring allowed the plane to survive longer. The opponent could still shoot, but the shots had a lower probability of kill because of the F-16 MATV's elusiveness. In one-versus-two defensive engagements against F-16s, the F-16 MATV was able to survive longer, but had difficulty in getting on the offensive. In neutral one-versus-two matches, the F-16 MATV could shoot or at least threaten the fighter wingman while continuing the fight with the lead fighter. It was also observed that once in the post-stall regime, the gun was the weapon of choice; missiles were used only sparingly.

"This jet is much more lethal than a normal F-16," said Capt. Jim Henderson of the 422nd. "In a one-versus-two engagement, it allows you to actually be offensive instead of defensive as in a normal jet. The limiter-off capabilities give you the opportunity to quickly kill one bandit and then engage the other - one on one. The bottom line is you have a greatly increased capability to survive and kill with this system."

In general, the final phase of the MATV program showed that thrust vectoring provides a significant advantage in terms of bringing armament to bear more quickly, in avoiding the risk of departure from controlled flight, and in negating offensive threats.

http://www.allbusiness.com/professional ... 119-1.html

IOWs, it certainly provides tactical options/advantages. As you point out, these are probably accentuated for larger birds, hence the MKI/Su-35 use it I s'pose. It may make some differnce to smaller birds as well in terms of take off distance - but there are pros and cons.

CM.

[naird]

But in WVR TVC has been proven to provide more survivability. Notice that a TVC plane can do all that a non-TVC plane can do, but the reverse is not true. However, earlier TVC used to come with tremendous weight penalties and hence the advantages in manoeuvrability would be mitigated by loss in agility. However, with what the Spanish have come out on the EJ-200 will be a game changer IMHO.

JMT

Indranil..but dont you agree that all the talks about TVC being superior in WVR is slowly becoming redundant with introduction of JHMCS or advanced HMS...you simply cannot defeat a 50-60g capable missile with TVC.

What all are your thoughts ?

[Austin]

The idea of TVC is not to defeat a 50 - 60 G WVR missile , the idea is to use a combination of JHMC/Sura-K ,WVR Missile with HOBS plus TVC to provide the niche advantage ( first shot ) in firing the missile in combat.

You can try to defeat those HOBS missile by using combination of manouvering, flares/decoys any be in future Laser to burn the seeker head to defeat it.

[Gaur]

naird,
IMHO, TVC is not meant to outmaneuver missiles, it is meant for BVR engagements.

However, your post brings us to a larger issue. There are people who say that modern missiles are highly maneuverable with advanced seekers. Hence, it is futile for a fighter to outrun them. They say that the only thing which can save a fighter from modern missiles is a superior EW suite. Others say that missiles, especially the seekers, are yet not advanced enough as the missile makers would like us to believe. Unfortunately, we have no idea of knowing who is correct.

However, some food for thought. If modern missiles really cannot be outmaneuvered, then it means that WVR is obsolete. This in turn means that maneuverability has no purpose. If this is indeed the case, then why is the world simply not making flying bricks with large payloads? Why F-22, PAK-FA, Eurofighter etc? If maneuverability was not an issue, then much better flying bricks can be made with large BVR missiles carrying capability and space for a lot of sensors. Remember how F-35 is being criticized for being not agile enough? First LM responded that it does not need to as it has stealth and sensors. But interestingly, it later tried to convince that F-35 is as maneuverable as F-16. Why did LM feel the need to do that? While I personally believe that LM has failed miserably with F-35, LM's task would have been infinitely easier if maneuverability was a non issue.

So, unless all the aircraft manufacturers and Air forces have no clue of current/near future missiles capability, I have difficulty believing the claims of all the missile and sensor manufacturers.

[Indranil]

Nair sahab,

Very good question. I really can only express my view on it.

The posters ahead of me have expressed very valid points. Gaur sahab points out what is now a common question for proponents who believe BVR is the end game. F-22, PakFa are the stealthiest planes, with the biggest radars, and furthest-reaching missiles. They shouldn't need much maneuverability. Instead both of them are the most maneuverable planes in the world. They could have been easily be made to carry more internal missiles if maneuverability could have been compromised.

Getting back to your question of WVR, before the missiles are fired, two planes would try to get the lock on each other first. Here the plane with TVC will have an advantage over the plane without TVC.

Also in a tail chase, if the plane can do post stall maneuvers when the missile is very close, it can help in breaking missile lock. This is because missiles can't do those maneuvers and would overshoot. Gaur sahab is right (I had told this before as well). If you are being chased by a missile and the missile is a more than 5 miles away, one would be very foolish to do a cobra maneuver. But if the missile is 300 mtrs behind and you did a "zoom" maneuver. It might help a lot because unlike you the missile can't slow down so fast.

TVCs are very useful for such extreme snap maneuvers and retaining control thereafter which can be very useful when the missile is very close. You can do the same maneuvers on a non TVC plane, except that the snap will be slower, which the missile has a better chance of tracking.

[Singha]

at high alt where control surfaces are sluggish, TVC can help the plane to remain nimble. also its been claimed a moderate use of TVC will minimize the use of control surfaces in wings which open the interior pipes and actuators (higher RCS) to hostile radar scans! but I think f22/JSF have gone to some length to minimize rcs off such exposed cavities as well?

[niran]

But if the missile is 300 mtrs behind and you did a "zoom" maneuver. It might help a lot because unlike you the missile can't slow down so fast.

a question
i have read modern missiles are programmed to blow up when it sense it is losing the target and the target is nearby or passing nearby
in light of this what use these manevours are for?

[Christopher Sidor]

F-15 is a air superiority fighter. It is meant to "sanitize" the airspace so that other aerial assets like F-16 can do their job. It is also meant for escort services for bombers and air-tankers. It is a costly plane to operate and is going to be replaced by F-22.

[Christopher Sidor]

TVC was meant to give an edge to the fighter in Dog-fights. It is not meant to overcome air-air missiles or ground-air missiles. With the speeds of current fighter and limits to human endurance, it is just not possible to out run present day missiles. With Beyond-Visual-Range missiles, it is likely that we might not see close air to air combat like we used to see previously. But just in the case a pilot does find himself in close combat, aka dog-fight, then TVC may enable the pilot to survive and eliminate his or her opponent.

Add to this fact is the terrain on which the fighter operates. In case the fighter has to evade the enemy, one of the best way is to hug the ground or fly as close as possible to land. On Sea this option is employed by sea-skimming missiles, whose main purpose is to prevent detection by enemy radar. Because on the sea a battleship/cruiser/carrier can employ counter measures like saturated firing, which will shoot down the missiles.
The other way to evade radar and missiles is to fly high and fly really fast. U-2, SR-71 and the rumored aurora plane use the 2nd option. U-2 flights continued till the soviets had a missile capable of catching upto U-2 and capable of operating at the ceiling of U-2. SR-71 has allegedly never been shot down. But was this due to some limitation of soviet missiles or due to some unstated understanding between Soviets and Americans cannot be said with any certainty.
There is a third way also, it is called stealth. However stealth has a problem. Once the fighter is detected, which can be done once a stealth fighter fires a missile or is detected by the human eye, most of its advantage vanishes. Moreover current stealth fighters will be detected as new radar systems, based on infrared and other technologies come online. That is why Agility is important.

So coming back to the point under discussion, more agile a fighter the better the fighter will be able to hug the terrain. With India requiring a fighter that can operate in Himalayas, the primary theater of Indian armed forces, agility becomes important.

[Gaur]

F-15 is a air superiority fighter. It is meant to "sanitize" the airspace so that other aerial assets like F-16 can do their job. It is also meant for escort services for bombers and air-tankers. It is a costly plane to operate and is going to be replaced by F-22.

USAF operates 267 Eagles and 223 Strike Eagles. USAF operates 166 F-22s. Only 21 more are F-22s planned. So, how will F-22 "replace" F-15s? F-22 replacing F-15s was the original plan when USAF expected to procure 650-750 F-22s.
However, that is now not possible.

Add to this fact is the terrain on which the fighter operates. In case the fighter has to evade the enemy, one of the best way is to hug the ground or fly as close as possible to land. On Sea this option is employed by sea-skimming missiles, whose main purpose is to prevent detection by enemy radar. Because on the sea a battleship/cruiser/carrier can employ counter measures like saturated firing, which will shoot down the missiles. ...................So coming back to the point under discussion, more agile a fighter the better the fighter will be able to hug the terrain.

Terrain Hugging is nothing new. It has been done for decades. You do not need F-22, PAK-FA, MKI level agility etc to do that. Even Sabre is more than capable for doing that.

However, given the modern AWAC dominant scenario, I doubt whether terrain hugging would do you much good. Low flying will work only against ground based radars. It used to work earlier on Air based Radars because look-down radars were not developed at that time. With AWACS, this trick will have limited use.

With the speeds of current fighter and limits to human endurance, it is just not possible to out run present day missiles. With Beyond-Visual-Range missiles, it is likely that we might not see close air to air combat like we used to see previously. But just in the case a pilot does find himself in close combat, aka dog-fight, then TVC may enable the pilot to survive and eliminate his or her opponent.

If one cannot escape from a missile, how would a pilot find himself in close combat? Why would a designer/AF develop a fighter for a scenario that, according to you, has a "just in case" chance of occurring. They would rather develop a large fighter with huge BVR carrying capacity so that it will never lose.

[Singha]

hmm...I thought at one point the USAF had close to 700 F-15 on the payroll? must be lot of retirements in f15c and no more building of f15e for quite a time.

[Gaur]

^^
Yes, total number of F-15s are indeed higher. The nos I mentioned are from USAF wiki page. Apparently, this is the figure only for number of F-15s on active duty. According to F-15 wiki page, USAF operated 630 F-15 aircraft (499 in active duty and 131 in ANG, all variants) as of September 2008. The source is AF magazine and hence credible.

[Dmurphy]

USAF operates 267 Eagles and 223 Strike Eagles. USAF operates 166 F-22s. Only 21 more are F-22s planned. So, how will F-22 "replace" F-15s? F-22 replacing F-15s was the original plan when USAF expected to procure 650-750 F-22s.
However, that is now not possible.

Gaur ji, why does replacing a particular aircraft with a superior one need to be done on one-to-one basis only? I know numbers play a big role too, but...

[Austin]

SR-71 has allegedly never been shot down. But was this due to some limitation of soviet missiles or due to some unstated understanding between Soviets and Americans cannot be said with any certainty.

Well SR-71 used to make flights near SU border areas , they never tried to penetrate deep inside though for obvious reason , but even the border flight stopped once couple of Mig-31 ambushed the SR-71 in operational spy flight , the SR-71 was locked by Mig-31 radar the US got the message.

[Gaur]

USAF operates 267 Eagles and 223 Strike Eagles. USAF operates 166 F-22s. Only 21 more are F-22s planned. So, how will F-22 "replace" F-15s? F-22 replacing F-15s was the original plan when USAF expected to procure 650-750 F-22s.
However, that is now not possible.

Gaur ji, why does replacing a particular aircraft with a superior one need to be done on one-to-one basis only? I know numbers play a big role too, but...

I agree. But are 187 F-22s equal to 650 F-15s? Perhaps (though I doubt that). But the point is that...if USAF wants capability only equal to 650 F-15s, why develop F-22s at all. They already have that capability. They can carry on the production of F-15s to replace the ones that retire.
It is like when the replacement of F-22 is developed (say F-XX), will they only produce 20 F-XXs because 20 F-XX = 187 F-22s = 700F-15s?

Also, it was not my assumption that 1:1 replacement is required, it was USAF itself which had projected requirement of 650 F-22s to replace F-15s. So, clearly USAF felt that one to one replacement of F-15s was necessary.

PS: Please, Gaur would suffice. There is no need for ji.

[Christopher Sidor]

USAF operates 267 Eagles and 223 Strike Eagles. USAF operates 166 F-22s. Only 21 more are F-22s planned. So, how will F-22 "replace" F-15s? F-22 replacing F-15s was the original plan when USAF expected to procure 650-750 F-22s.
However, that is now not possible.

Americans will retain and upgrade the F-15 due to the cost factors involved in F-22 Raptor program. But to put a F-15 against F-22 is madness. F-15 looses hands down. Dont forget F-22 & F-35 are designed with one thing in mind to out-perform all the existing 4 generation and 4.5 generation fighters. F-15 is a 4th generation air-superiority fighter.

With the speeds of current fighter and limits to human endurance, it is just not possible to out run present day missiles. With Beyond-Visual-Range missiles, it is likely that we might not see close air to air combat like we used to see previously. But just in the case a pilot does find himself in close combat, aka dog-fight, then TVC may enable the pilot to survive and eliminate his or her opponent.

If one cannot escape from a missile, how would a pilot find himself in close combat? Why would a designer/AF develop a fighter for a scenario that, according to you, has a "just in case" chance of occurring. They would rather develop a large fighter with huge BVR carrying capacity so that it will never lose.

Scenario 1: A fighter or a couple of fighters are returning to their base from a mission after exhausting their air-air missiles. In the meantime they are intercepted by the enemy fighters.
Scenario 2: A MRCA fighter or a group of fighters manages to evade the enemy radar and runs into SU-30MKK/Su-27 fighter(s) or the proposed 5th generation chinese fighter.

BVR makes Dog-fights unlikely, but does not eliminate them entirely. Also a fighter can carry only so many air-air BVR missiles. For example a Su-30 can carry 10 air-air missiles. While a Grippen (not Grippen NG) can carry some 6/4 air-air missiles.

I said out run and not escape . The speed of most air-air missiles is in the range of 2.5-4.5 Mach. Contrast this with the max speed of a fighter like Su-30 MKI, EFT and Grippen (not Grippen NG) which is Mach 2. A fighter can still escape BVR missiles by using countermeasures like flares, electronic, etc. A fighter with a huge BVR capability is best suited for air dominance. It can clear the skies of the opposing fighters. IAF on the other hand wants a multi-role fighter and not a specialist fighter. Capable of handling various mission assignments. So if we design a fighter with huge BVR missiles, it might leave the fighter ill suited for other roles.

[naird]

Saar- my thoughts

naird,
IMHO, TVC is not meant to outmaneuver missiles, it is meant for BVR engagements.

BVR ?? This is surprise. How will TVC help in a BVR engagement ?

However, some food for thought. If modern missiles really cannot be outmaneuvered, then it means that WVR is obsolete. This in turn means that maneuverability has no purpose. If this is indeed the case, then why is the world simply not making flying bricks with large payloads? Why F-22, PAK-FA, Eurofighter etc? If maneuverability was not an issue, then much better flying bricks can be made with large BVR missiles carrying capability and space for a lot of sensors.

Since we are discussing TVC - lets leave aside conventional maneuverability for the moment. This brings us to the question , why F22 and PAKFA has TVC ? The TVC in PAKFA i feel is a result of Russian fascination with super maneuverability. After all Russians have been the biggest proponents of TVC with their su series -- to not include TVC in PAKFA would be akin to saying "we dont believe in TVC concept anymore". Why F22 ? I can only guess that when F22 was realised it was purely meant to counter the Russian fighters , and how better to demonstrate that US was ahead of the game than to include to TVC in a stealth package. If US or any Nato nations would have believed in TVC , we would have definitely seen more of this concept in their next new series of fighters visa vi F35, EF and RAFALE

Remember how F-35 is being criticized for being not agile enough? First LM responded that it does not need to as it has stealth and sensors. But interestingly, it later tried to convince that F-35 is as maneuverable as F-16. Why did LM feel the need to do that? While I personally believe that LM has failed miserably with F-35, LM's task would have been infinitely easier if maneuverability was a non issue.

F35 is Achilles heel is not only that it is not agile enough but also due a to poor payload. You simply cannot tell the old school F15 , F22 pilots that a plane which is not maneuverable and which doesn't have a great payload will still be a great fighter. Critics just picked up the bone with maneuverability.

[naird]

Getting back to your question of WVR, before the missiles are fired, two planes would try to get the lock on each other first. Here the plane with TVC will have an advantage over the plane without TVC.

roy saab - I agree that in WVR before the missiles are fired two planes would try to get lock on each other (not entirely true these days with lock on after launch concept). But how will a plane with TVC have an advantage over a plane with lets JHCMS or latest DASH. ? No matter whatever maneuver a plane does ,if the opposing fighter pilot is able to see it then the missile seeker will be able lock on it.

Also in a tail chase, if the plane can do post stall maneuvers when the missile is very close, it can help in breaking missile lock. This is because missiles can't do those maneuvers and would overshoot. Gaur sahab is right (I had told this before as well). If you are being chased by a missile and the missile is a more than 5 miles away, one would be very foolish to do a cobra maneuver. But if the missile is 300 mtrs behind and you did a "zoom" maneuver. It might help a lot because unlike you the missile can't slow down so fast.

If the missile is 500 mtrs behind and if you do a zoom maneuver the missile might not hit you at that moment instead it will describe a radius of turn and come back at you. This close you simply cannot outrun a missile. Also these days even missiles are equiped with TVC - you do a zoom maneuver and it will closely follow you. Your best bet is to jam it -- but then a plane without a TVC will also be able to do it.

IMHO the days of TVC are over with the advent of next gen HMS technologies. Minimal RCS coupled with a good payload is definetly the way to go.

[Henrik]

^^

It should be noted that a missile doesn't necessarily need a direct hit to cause severe damage. It could fragment close-by, thus enlarging the "kill zone".

[Gaur]

naird sahab,
My mistake. I meant WVR. Truly, I cannot see how TVC can help in a BVR scenario.
IMO, we cannot leave aside conventional maneuverability when discussing TVC. The primary job of booth is to have the ability to line up first and take the shot. Targeting using HMS is very useful indeed. But first you have to line up to give the missile a good probability to hit. I get the feeling that you think that post stall maneuvers are not very useful in real combat? OK..I respect your opinion even though I may not agree with it. However, I hope you would agree with me that AOA and turn rate are the 2 primary attributes of any fighter. Considering that TVC greatly helps in AOA, IMO, its usefulness to line up in BVR engagements cannot be easily dismissed.


Also, you have to remember that it were the Russians who introduced HMS long before US developed one. So, who knows the impact of HMS in BVR engagement more than Russians? So, it is clear that the Russians thought that the combination of HMD and super maneuverability is the right way to go. Also, I have to respectfully disagree regarding your statement that Russians are "fascinated" with super maneuverability and TVC. Russians are not children. We armchair marshals look at brochures, OEM claims, marketing stuff etc and get enamored by it. On the other hand. Russian AF and designers have studied,tested and used all the above for decades. If super maneuverability and TVC was not of much value, they surely would not have wasted their limited credit to develop PAK-FA with that in mind.

Regarding F-35. True, its payload is also a huge concern but that is exactly my point. My understanding is that designing fighter is a compromise. To increase one attribute, you will have to sacrifice another. It is always a compromise. So, perhaps F-35 would not have to make a compromise in payload if maneuverability was not an issue? Perhaps, the airframe design could have been changed to accommodate larger internal bay at the cost of agility? Again, I am no aeronautical engineer. I am just giving my though process.

[Gaur]

Christopher Sidor,
I have already given my thoughts regarding the matter to you, naird and Dmurphy. So, anything I say again would be repeating myself.
Cheers.

[nrshah]

To continue where Gaur left,

We continue to hear that the days of WVR are over (Specially after JSF was felt to be less agile and maneuverable) on one side, whereas on the other side, we claim with stealth technology, detection range will be reduced drastically...

Now, I dont understand which of the above statement is correct...

If F 22 and PAk FA cannot detect each other at say more than 30 kms, do we have the time to go for a BVR shot?

Why does the proponents of first statement (read LM) still design weapon bays to accommodate WVR missile? I mean, they could have been better off having additional BVR missile instead...And why a Gun????

Scenario 1: A fighter or a couple of fighters are returning to their base from a mission after exhausting their air-air missiles. In the meantime they are intercepted by the enemy fighters.
Scenario 2: A MRCA fighter or a group of fighters manages to evade the enemy radar and runs into SU-30MKK/Su-27 fighter(s) or the proposed 5th generation chinese fighter.

But than still as claimed they cannot over run a missile, and the only defense is EW as has been made out to be, they why agility? As Gaur mentioned, we will be better off having a plane (flying brick) with high no of BVR missiles and very sophisticated EW... All the discussions on Gs of Gripen or tejas slow turn rate should not matter...

[naird]

naird sahab,
My mistake. I meant WVR. Truly, I cannot see how TVC can help in a BVR scenario.
IMO, we cannot leave aside conventional maneuverability when discussing TVC. The primary job of booth is to have the ability to line up first and take the shot. Targeting using HMS is very useful indeed. But first you have to line up to give the missile a good probability to hit. I get the feeling that you think that post stall maneuvers are not very useful in real combat? OK..I respect your opinion even though I may not agree with it. However, I hope you would agree with me that AOA and turn rate are the 2 primary attributes of any fighter. Considering that TVC greatly helps in AOA, IMO, its usefulness to line up in BVR engagements cannot be easily dismissed.

Saar i do agree that AoA and turn rate are the 2 primary attributes of any fighter where a WVR engagement used to happen in a merge , line up and shoot scenario. However with advent of advanced HMS and equally advanced missiles the concept of lining up the fighters and then shooting the missiles is becoming redundant at a great pace. The days when fighter a/c had to position its nose cone to 45 deg to 60 deg to enemy fighter to achieve a lock on & shoot has been quickly over shadowed with HMS coupled with advanced missiles. Mig 29 started it and the Americans were very vary of getting into a 45 deg cone when fighting with Mig 29's. But these days there is no limitation on HMS. It doesnt matter what AoA or turn rate a fighter describes if the opposing enemy fighter with JHMS and AIM 9X is able to see you then chances are good that your a/c will be locked on. Python 5 advertises the fact in a tail chase scenario if you can look behind and see the enemy fighter chasing then the python imaging seekers can also achieve a lock on via a DASH helmet - AIM 9X can also do the same 360 deg approach. JHMCS is better, it can even see the enemy fighters below the floor of aircraft without maneuvering the a/c.

Also, you have to remember that it were the Russians who introduced HMS long before US developed one. So, who knows the impact of HMS in BVR engagement more than Russians? So, it is clear that the Russians thought that the combination of HMD and super maneuverability is the right way to go.

These were two seperate developments with HMS being developed first for Mig 29 and later on TVC being incorporated with Su's. However please consider the fact that when Russians developed HMS the full potential of the technology was not realised -- TVC still had a lot of role with SURA type helmets where enemy fighter could not be targeted over the entire visual spectrum. It made perfect sense to have both coupled then. However this is not true in todays scenario.

Also, I have to respectfully disagree regarding your statement that Russians are "fascinated" with super maneuverability and TVC. Russians are not children. We armchair marshals look at brochures, OEM claims, marketing stuff etc and get enamored by it. On the other hand. Russian AF and designers have studied,tested and used all the above for decades. If super maneuverability and TVC was not of much value, they surely would not have wasted their limited credit to develop PAK-FA with that in mind.

I did not mean to belittle Russians. They are geniuses in their own rights. However when compared with the amount of R&D that takes place in US/Nato nations it would seem IMO(no disrespect) that they are clinging on to a old philosphy and are afraid to let go of their main advertising strong points .i.e TVC. Please also consider the fact that Americans inserted TVC on F16 (removed later due to weight penalities) and then later on they incorporated it onto F22. It made perfect sense then since HMS technology was not evolved. The moment they sensed the direction of air warfare they did not include it for F35 and likewise for EF/RAFALE. If TVC indeed had great advantages then i am sure that we would have seen TVC in the next line of fighters considering the fact that NATO is always trying to be one up on mother russia.

Regarding F-35. True, its payload is also a huge concern but that is exactly my point. My understanding is that designing fighter is a compromise. To increase one attribute, you will have to sacrifice another. It is always a compromise. So, perhaps F-35 would not have to make a compromise in payload if maneuverability was not an issue? Perhaps, the airframe design could have been changed to accommodate larger internal bay at the cost of agility? Again, I am no aeronautical engineer. I am just giving my though process.

Your views are spot on. But then F35 made a compromise on both payload and agility. They banked too heavily on VLO aspect which on the face of it looks great but somehow it did not fly down well with old school USAF. Just pure speculation , we may never know.

[naird]

To continue where Gaur left,

We continue to hear that the days of WVR are over (Specially after JSF was felt to be less agile and maneuverable) on one side, whereas on the other side, we claim with stealth technology, detection range will be reduced drastically...

Now, I dont understand which of the above statement is correct...

If F 22 and PAk FA cannot detect each other at say more than 30 kms, do we have the time to go for a BVR shot?

Why does the proponents of first statement (read LM) still design weapon bays to accommodate WVR missile? I mean, they could have been better off having additional BVR missile instead...And why a Gun????

30 KMs?? Nope saaar. If PAKFA and F22 are what they are advertised to be then detection of each other will be in WVR range. It would be akin to putting two cowboys in a small rectangular room for a duel resulting in a MAD (Mutually assured destruction) situation . I think the fight between these two fighters would also be in the same vein.

Second reason for a WVR missile would be to first visually identify a boggie and then possibly shoot it down. Numerous other possibilities.

[Indranil]

Nair sahab, frankly to say that TVC in F-22 and PakFA to show off is the lamest excuse I have heard till now. You are softly alleging that designers and policy makers of the two biggest aircraft making nations add extra weight to their most advanced planes as a show off. Oh and then may be the aircraft guns should be a show off as well.

Coming to JHMCS. You might lock on to a plane which is at between your 3 o'clock and 9 o'clock, but the efficacy of that missile is greatly reduced. you might want to read up on that.

Coming back to countering the missile using post stall maneuvers. Well it depends on the missile. If it is acting on it's own radar, if it shoots past the plane there is a low possibility that it will maintain radar lock.

If the missile is guided by the radar of the enemy airplane, then the pursuing plane can continue to guide it. However, your assumption that it will be able to do a 180 degree loop and catch the plane again is not correct. In that case, it has to a 360 degrees. The zoom maneuver makes the plane gain 100 metres or so, for a 180 degree turn the missile would have to have a turning radius of 50 metres, which I don't think is possible. For getting inline it has to make a 360 degree turn. Other wise, it will have to fly further ahead and make sure that after the inside loop, it is still ahead of the plane.

In either case the efficacy of the missile after all these missiles would be greatly reduced.

I am not trying to say the TVC plane will not employ countermeasures or jamming. But in this game of catch up where the plane can never outrun or out turn a missile, anon TVC plane can gain by going to a flight envelope which the missile can't match by flying and maneuvering at below the stall speed of the aircraft.

It's just an additional option with a TVC plane which a non TVC plane doesn't have.

[Indranil]

Many of you are right that modern day missiles, have a bigger kill zone by employing proximity switch or exploding on loss of lock.

[nrshah]

30 KMs?? Nope saaar. If PAKFA and F22 are what they are advertised to be then detection of each other will be in WVR range. It would be akin to putting two cowboys in a small rectangular room for a duel resulting in a MAD (Mutually assured destruction) situation . I think the fight between these two fighters would also be in the same vein.

Second reason for a WVR missile would be to first visually identify a boggie and then possibly shoot it down. Numerous other possibilities.

Exactly my point... If the new gen fighters (ready to dominate the world by next decade - US and allies going for F22/F35, India and Russians going for Pakfa/FGFA/AMCA, China and other third world countries betting on JXX, Sooner or later other EU countries will also go the US way), most of the detection will happen in WVR range... The air war will be somewhat akin to submarine warfare today where detection itself will be at very less distance... Hence maneuverability and agility will be required... Probably this is the reason, russian have opted for increased maneuverability and agility even though they had to sacrifice on Stealth...
TVC is just a tool to enhance / improve the same.

On your second point, We assuming the enemy will also wait for us to get a visual on the him... But anyways, even then we are talking of WVR shots where TVC can play important role

The whole point was TVC is not useful as it cannot help aircraft avoid modern missile fired at BVR ranges.

Although, my knowledge is limited, TVC can help break a radar lock considering it will work in tandem with EW which would be busy burning / blinding the missile seeker... A sudden flip using TVC, might help breaking the radar lock also considering, unlike a/c radar, the degree of area missile's seeker can scan is miniscule to that of Aircraft and as such targeted aircraft has to be with in limited arc of scan...

Secondly, TVC can also help you in getting a better firing solution or giving it faster than the opponent... Consider the sudden detection of enemy (as they will be operating in EMCON with redar on stand by guided be a awacs and with data link capabilities)... In such a case the faster you get the firing solution, you will be at advantage...

Third, although we keep on debating on BVR, what percentage of actual shots are fired at maximum ranges.. I read somewhere, over 75% of missiles are fired within 20 Miles distance...This itself is evident from missile ranges which are more than often mis-represented... For eg Astra with a stated range of over 80 kms has range of only 21 kms when fired at low altitude...Do we expect a AIM 120D to be fired at 150 Kms....?

[Singha]

exploding on loss of lock does not make sense if the missile is expected to run and attempt reacquire the target again.

[Indranil]

^^^ Ofcourse the missile won't explode if it is 10 miles away.

But when the missile is in close proximity of the plane it is chasing down, then when will it lose lock? It would be only if the aircraft was very close and suddenly did something which made the aircraft go off-bore sight of the missile. Notice that if the aircraft was far enough it can't do much to go off bore sight as the projection in change of angle of incidence will be much smaller and within the limits of the cone of the missile radar.

Thus if the missile has lost lock suddenly, then this is the point when the missile be closest the aircraft. Once it has lost lock, it has to scan everywhere and if it has overshot the plane, then well well.

So losing lock is close to wasting the missile, it rather blow up when it is as close to the aircraft as possible.

JMT.