Gripen News

Military aircraft - Post cold war aircraft, including for example B-2, Gripen, F-18E/F Super Hornet, Rafale, and Typhoon.
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aaam

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Unread post23 Aug 2017, 22:05

basher54321 wrote:F-14A very likely had the higher T/D and was far better aerodynamically - however the F-14A also had about 6000 lbs more total max static thrust over the F-4S on given figures.

The lower powered F-16C Block 50/52 (~29,000 lbs) have about 7000 lbs more static max thrust over the Gripen E (~22,000 lbs) - so call me mr pessimistic but if looking at drag I wont be putting my money on Gripen E for that contest either. :beer:



Not sure what you mean by "lower powered" F-16C Block 50/52. Aren't all of those blocks powered by an ~ 29,000 lb engine? I would say from appearance that an A2A loaded Gripen E looks less draggy but I don't have hard figures for either. In any case, I'm not saying that at low altitude an Gripen E will out accelerate an F-16. What I'm saying is that just because a Gripen E has a lower T/W at gross (F-16 C/D, the V is heavier), and I'm not sure if that applies at combat weight doesn't mean it's underpowered or that Saab is frantic fo a new engine.

There's an interesting comparison of the two aircraft at https://sofrep.com/61519/dogfight-f-16v ... ipen-wins/. Not endorsing it, just saying that it's interesting. the author is "... is a retired USAF F-16 fighter pilot, current Lockheed Martin test pilot, LO SME, aviation enthusiast, and author".

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basher54321

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Unread post23 Aug 2017, 23:18

aaam wrote:
Not sure what you mean by "lower powered" F-16C Block 50/52. Aren't all of those blocks powered by an ~ 29,000 lb engine? I would say from appearance that an A2A loaded Gripen E looks less draggy but I don't have hard figures for either. In any case, I'm not saying that at low altitude an Gripen E will out accelerate an F-16. What I'm saying is that just because a Gripen E has a lower T/W at gross (F-16 C/D, the V is heavier), and I'm not sure if that applies at combat weight doesn't mean it's underpowered or that Saab is frantic fo a new engine.

There's an interesting comparison of the two aircraft at https://sofrep.com/61519/dogfight-f-16v ... ipen-wins/. Not endorsing it, just saying that it's interesting. the author is "... is a retired USAF F-16 fighter pilot, current Lockheed Martin test pilot, LO SME, aviation enthusiast, and author".



Meant lower powered over the GE-132 (unlikely to be on any Vs currently) - any new Vs would be as advertised.

I know what you are saying however you cannot tell jack by looking at a photo - and without flight test data there isn't much to go on - so all there are is the advertised figures which suggest the F-16 has a higher T/W across the weight range and has a very significant 7000 lbs more max thrust to overcome any extra drag (assuming there is any & depending on config)


The article was originally here https://fightersweep.com/6024/dogfight- ... 9e-gripen/
Someone in the comments corrects his incorrect figures for T/W :D
Last edited by basher54321 on 23 Aug 2017, 23:45, edited 1 time in total.
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XanderCrews

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Unread post23 Aug 2017, 23:25

aaam wrote:
T/W is certainly a factor, but it's not the only, or even the most important factor.


But in this case we are comparing Gripen to Gripen. Let's take a Gripen, give it more thrust but a lot more weight too and expect... What exactly?

Compare a MIG-29 to and F-16 And we have a lot to look at. Take Gripen C and compare to a Gripen E, when Gripen E is trying to be as similar as possible and we can make pretty accurate guesses based on the last 20 years of Gripen ops right?
Last edited by XanderCrews on 24 Aug 2017, 04:03, edited 1 time in total.
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XanderCrews

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Unread post24 Aug 2017, 03:56

ikea99 wrote:"

If you look at the tests done with electronic warfare, gripen c/d (the one tested) had just about the same performance as the most expensive Rafale (the new one in Gripen E will be better with attack ability s etc).



Can you post that please?


And i didn't even see any RCS tests in there of the aircrafts, here Gripen E will be a clear winner since its new built and Swaf had demanded "significantly" lowered RCS ( of a already low RCS).


I would like to know how it's "low RCS"

and I also want to see how they are going to change the RCS given that the airplane is externally the same save for some small details

I would like to see where swaf demanded lowered RCS as well. Because the saab boss dismissed stealth as obsolete just a few years ago. So some stories are not matching up here.



The point is ! The Swiss Gov. didn't make a mistake, they choose Gripen as their winner since it was the most sensible choice.


It disagreed heavily with what the evaluation felt was sensible. Hence the report leaked. Hence the revelation that Gripen fell short of even the F-18. Gripen often placed 3rd or 4th if you Include F-18



You can run two gripens ,at least, for the price of the other ones.


Standing by for comparative numbers
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Unread post24 Aug 2017, 12:07

ikea99 wrote:"Switzerland didn't buy the Grippen. Thank god we have a Direct democracy.

And in the Evaluation by the Swiss Airforce, the Gripen was far behind the Rafale and Eurofighter."

To be fair, an evaluation is not a competition. In a evaluation you look for what is possible to do with a "thing" and in a competition one wins. That said, Gripen E leaked eval in 2008 where only the first evaluation done and the last eval was done many years later when Saab even knew what would be inside gripen for real. To point out once more, the test evaluation was to see what the aircraft could be used for, and if it could manage to do the tasks given to them by the Swiss air force, it wasn't a competition. Absolutely not in 2008 anyway.

The final results where following Rafale(6,98), EF(6,48), Gripen MS21 (5,33). The difference between the best Rafale and the worst Gripen where 23,6%. Not really strange if you ask me. Gripen is a single engine aircraft.

If you look at the tests done with electronic warfare, gripen c/d (the one tested) had just about the same performance as the most expensive Rafale (the new one in Gripen E will be better with attack ability s etc). And i didn't even see any RCS tests in there of the aircrafts, here Gripen E will be a clear winner since its new built and Swaf had demanded "significantly" lowered RCS ( of a already low RCS).

The point is ! The Swiss Gov. didn't make a mistake, they choose Gripen as their winner since it was the most sensible choice. You can run two gripens ,at least, for the price of the other ones.


There was a 2 technical evolution in 2009. with all 98! upgrades for the Gripen (Aesa Radar irst etc.) And he still no achieve a 6 in a scale from 1-9. 6 means minimum capabilities and represents the Hornet C/D. Sorry you don't buy a fighter who is worse then the Fighters you already have.

And the Gripen E should be delivered 2018 to the swiss AF. But as far as i know the first Prototype flown this year, and will be delivered maybe 2021 to the swedish AF. At least 3 years later then promised.

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Unread post24 Aug 2017, 20:10

^Swiss for the win^

There is not an airplane out there that is harder to find real data on than the Gripen, and especially the Gripen E and that's largely thanks to Saabs peerless marketing and the legions of fanboys who spread disinformation (often unwittingly) but frustrating nonetheless about this airplane
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Unread post25 Aug 2017, 00:48

wewuzkangz wrote:
What do you mean that the Gripen is overweight?


aaam wrote:
Not sure what the basis is for saying they are badly short of thrust.


Simple question, meet simple answer:





You would *think* that would be the end of it. Power-to-weight ratio or thrust-to-weight ratio has been an accepted metric of fighter maneuverability for decades. If you don't understand why, consider reading a book on the subject. Or, you know, thinking about it in terms of high-school level physics. It's pretty obvious why this matters. But noooooo...


wewuzkangz wrote:
I referred to the c/d Version instead of the E version.....E version in which they referred to themselves are currently looking to upgrade engines because for them they say it is cheaper


When I mentioned that the Gripen is short of thrust, I explicitly mentioned E/F. Stop trying to save face.

You know, for someone maladroit enough to try and discuss racial psychometrics on an aviation technology forum, I must say that you are a convincing argument for eugenics. No, not that you make a compelling argument for eugenics. I'm saying that you are a compelling argument for eugenics.

aaam wrote:There seems to be a lot of repetition that the Gripen E is overweight and underpowered and that Sweden is desperately searching for a more powerful engine. To me at least, it appears that this is centered around the fact that its T/W ratio at gross is not as high as that of the F-16. The thing is, that is only one of many factors making up an aircraft's capabilities. Turn rate, drag, high alpha performance, ability to regain energy play in, as do sensors and weapons, availability and support, networking, etc.. What I'm saying is that just because they don't match the F-16 doesn't mean they aren't satisfied.


Think about what you're saying for a second.

The Gripen E/F has wings that are only .2 meters wider than the Gripen C's. This means that the wings are going to be producing about the same amount of lift, but they are trying to shift an airframe that has about 17% more mass (going by the empty masses, Gripen E is supposed to carry more fuel so the comparison might be even less in its favor). That means that to achieve the same number of Gs the Gripen E will need to pitch to a higher AOA, which in turn means more induced drag. More drag wouldn't be a problem if it had more thrust to offset that drag, but it doesn't have thrust proportional to the increase in mass.

What's more is that you don't want to have to resort to higher AOA to achieve a given amount of Gs because of the way drag polars are shaped. Higher AOAs increase lift coefficient, but they increase drag coefficient faster than they increase lift coefficient. This is why the fighter mafia harped on the importance of wing loading.

In other words, turn rate is substantially a function of thrust to weight ratio. The Gripen E/F's turn rate will be degraded compared to the Gripen C's because its thrust to weight ratio is degraded. The aerodynamics just aren't different enough between the two for this not to be the case.

The same thing goes for sustained turn rate. High alpha performance? Why would the E/F have any advantages here? SAAB barely changed any of the external aerodynamics, how much could these have improved?

It's a pretty straightforward case that the Gripen E/F has worse agility than the Gripen C/D.
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Unread post25 Aug 2017, 22:57

collimatrix wrote:
wewuzkangz wrote:
What do you mean that the Gripen is overweight?


aaam wrote:
Not sure what the basis is for saying they are badly short of thrust.


Simple question, meet simple answer:





You would *think* that would be the end of it. Power-to-weight ratio or thrust-to-weight ratio has been an accepted metric of fighter maneuverability for decades. If you don't understand why, consider reading a book on the subject. Or, you know, thinking about it in terms of high-school level physics. It's pretty obvious why this matters. But noooooo...


wewuzkangz wrote:
I referred to the c/d Version instead of the E version.....E version in which they referred to themselves are currently looking to upgrade engines because for them they say it is cheaper


When I mentioned that the Gripen is short of thrust, I explicitly mentioned E/F. Stop trying to save face.

You know, for someone maladroit enough to try and discuss racial psychometrics on an aviation technology forum, I must say that you are a convincing argument for eugenics. No, not that you make a compelling argument for eugenics. I'm saying that you are a compelling argument for eugenics.

aaam wrote:There seems to be a lot of repetition that the Gripen E is overweight and underpowered and that Sweden is desperately searching for a more powerful engine. To me at least, it appears that this is centered around the fact that its T/W ratio at gross is not as high as that of the F-16. The thing is, that is only one of many factors making up an aircraft's capabilities. Turn rate, drag, high alpha performance, ability to regain energy play in, as do sensors and weapons, availability and support, networking, etc.. What I'm saying is that just because they don't match the F-16 doesn't mean they aren't satisfied.


Think about what you're saying for a second.

The Gripen E/F has wings that are only .2 meters wider than the Gripen C's. This means that the wings are going to be producing about the same amount of lift, but they are trying to shift an airframe that has about 17% more mass (going by the empty masses, Gripen E is supposed to carry more fuel so the comparison might be even less in its favor). That means that to achieve the same number of Gs the Gripen E will need to pitch to a higher AOA, which in turn means more induced drag. More drag wouldn't be a problem if it had more thrust to offset that drag, but it doesn't have thrust proportional to the increase in mass.

What's more is that you don't want to have to resort to higher AOA to achieve a given amount of Gs because of the way drag polars are shaped. Higher AOAs increase lift coefficient, but they increase drag coefficient faster than they increase lift coefficient. This is why the fighter mafia harped on the importance of wing loading.

In other words, turn rate is substantially a function of thrust to weight ratio. The Gripen E/F's turn rate will be degraded compared to the Gripen C's because its thrust to weight ratio is degraded. The aerodynamics just aren't different enough between the two for this not to be the case.

The same thing goes for sustained turn rate. High alpha performance? Why would the E/F have any advantages here? SAAB barely changed any of the external aerodynamics, how much could these have improved?

It's a pretty straightforward case that the Gripen E/F has worse agility than the Gripen C/D.



pretty much!^

Sweden is desperately searching for a more powerful engine.


No they are not. They picked the F414 to keep things as easy as possible, its too late now. They aren't going back to square one to throw anything else back there. Its basically The F414 or derivatives of it, Derivatives that add cost. Ehanced engine performance comes at the cost of engine life and more Maintenance. Not exactly a good trait for the ol' cheap and easy fix Gripen


The original "goal weight" was 7000 KG:

http://www.ziuaveche.ro/wp-content/uplo ... s-F-16.jpg

But they missed that by 1000 kilos. F414 made fine sense when it was 7000, 8000? not so much. But as I said. Too late now. Theyre going to have to live with it. The MTOW didn't increase with that weight increase either. So its less usable carriage of things that add range or help the bad guys die.

Oh well, should have bought F-16s.
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f-16adf

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Unread post26 Aug 2017, 14:17

As the Gripen keeps gaining weight, even with more thrust, some of its performance metrics will suffer.
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Unread post26 Aug 2017, 18:46

The truth is a very small attrition rate would be devastating, so in actual combat both fighters will jockey for an advantage that doesn't leave them vulnerable. In these games they can take risks.

The big weakness that keeps being brought up against Gripen NG is fuel fraction. The Gripen NG would largely operate where fuel is optimal, so that discards a disadvantage there. The F-16V would be operating where it could ditch excessive fuel before an engagement, therefore its neither at an advantage or disadvantage there.

The F-16V wouldn't have any maneuver advantages over Gripen NG. It would have perhaps a radar advantage, but I'm not sure you can emit even with LPI without making your presence known. Eurofighter had a distinct maneuver advantage over Gripen C without being able to neutralize it. And Gripen C was able to keep Eurofighter at bay when it was emitting with its bigger, more capable radar due to its SA acquired by the internal electronic warfare suite. If Gripen NG truly is stealth I see no advantage going to F-16V.

Any attrition rate is counterproductive. Both sides are happy settling for mission kills over potential losses.
Last edited by madrat on 27 Aug 2017, 01:01, edited 2 times in total.
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Unread post26 Aug 2017, 22:24

madrat wrote:If Gripen truly is stealth


What?
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Unread post27 Aug 2017, 00:58

We have no reason to believe the Gripen NG will be stealth in the same vein as an F-35. The original Gripen is optimistically VLO from some angles, but that doesn't make it stealth any more than Super Hornet, Rafale, or Eurofighter, all of which were carefully shaped and configured to be difficult to search or track by radar. I don't think Saab is any more privy to American stealth technology than any other outsider to the program.
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Unread post27 Aug 2017, 14:12

madrat wrote:We have no reason to believe the Gripen NG will be stealth in the same vein as an F-35. The original Gripen is optimistically VLO from some angles, but that doesn't make it stealth any more than Super Hornet, Rafale, or Eurofighter, all of which were carefully shaped and configured to be difficult to search or track by radar. I don't think Saab is any more privy to American stealth technology than any other outsider to the program.


I just have no idea where the Gripen got this reputation for being "stealthy" or "LO" most of the fanboys I see sighting such things are saying its LO thanks to its small size which is poppycock. The only stealthy feature I see on it is a hidden engine face. Other than that it has a single straight tail, slab sides, and canards.

IF the Gripen is LO, then This must be more even more stealthy:

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Unread post27 Aug 2017, 15:11

SAAB were pushing something called "E Stealth" at the NG launch whatever that is - it isn't anything to do with shaping though because in that regards it is a conventional aircraft - Grip/Raf et al might have had RCS reduction through RAM and composite components but likely nothing significant when you stick on the external stores.


I have seen with my own eyes how Gripen A is seen by radar systems in real world exercise and I must say it's not that different to F/A-18C, F-16 MLU or Mirage 2000-5. The difference in radar detectability and thus RCS seemed to be fairly small between all of those. I don't know what the aircraft were carrying during the exercise but it was large scale (up to about 40 aircraft in the air simultaneously) air combat exercise. All pictures I've seen, all aircraft have carried 1 or 2 EFT. I can believe Gripen has the lowest RCS of those mentioned, but it's not LO and definitely not VLO at any angle. C-model may have some minor improvements but there is no way it has seriously lower RCS than A-model.
.......



viewtopic.php?f=55&t=11311&p=318189#p318189
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Unread post31 Aug 2017, 20:41

The official said the Request for Information will be issued in a couple of months for approximately 100 single-engine fighters, out of which 18 will be brought to India in a fly-away condition. The rest will be manufactured under ‘Make in India’ and will include technology transfer as mandated in the SP Model.

The official confirmed only two aircraft available in the global market — F-16 and Gripen — meet IAF’s requirement criteria.


Full story: http://indianexpress.com/article/india/ ... s-4823046/

The battle lines are becoming clear in the globally watched, multi-billion dollar contest to build 100-200 single-engine fighters in India for the Indian Air Force (IAF).  Business Standard learns that, on Friday, Swedish defence and aerospace major, Saab, will announce a partnership with the Adani group to manufacture defence equipment in India, including Saab’s new Gripen E single-engine, medium fighter if that is chosen by the IAF.


http://www.business-standard.com/articl ... 040_1.html
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