SAAB Gripen and Gripen NG thread #4

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@ Hopsalot "What possible utility is a max weight comparison?" Well, more utility then an empty comparison which you always like to give out. A good calculation would be 50% fuel and 3 air to air, where Gripen lands on 10,6ton and F-35 at 17900 with 3 aim-120. At this weight f-35s engine is luckily 25% stronger but still has 35% less wing area for lift and turn and still has at least 2-3 times the air-resistance (weapons included) so it most likely need it, to compensate lift/drag with the engine and very much so in anything above speed of sound and while lift of and landings.

Any comparison at an equivalent fuel percentage favors the F-35 because the F-35 has a much higher fuel fraction. (That was the point of my inclusion of the fuel capacities)

Put another way... an F-35 at 50% fuel can go a lot farther and stay a lot longer. A Gripen at 50% (internal) fuel had better already be on its way home.

The fact that even in that scenario the F-35 has a huge advantage in thrust to weight should tell you something. Also, you are wrong about their relative drag. Certainly the F-35 is a larger and draggier aircraft... but it also has almost twice the thrust and is carrying its load internally. There is no reason to think this is an area of advantage for the Gripen NG.

"Supercruise at M1.1 isn't tactically useful" well that is...not right at all. Low super-cruise is much more usable then high speed super-cruise since the fuel requirements at high super-cruise is terrible, a few minutes of super cruise is what you get at super-cruises @ high supersonic (f-22) 10 minutes at 1,8 then fuel is gone. Super-cruise has been done by Gripen demo at mach 1,25 and at that speed it would be able to travel for quite some time (35-55min on internal depending on load). Maybe to travel back for reload without turning on the afterburner (ir protection) or going for a faster assault. Super-cruise at mach 1.1 is in fact useful in many ways and one of them is to fire missiles above the sound barrier saving up to 50% range.

You are wrong again. Flying at M1.1 means you are transonic... high transonic maybe, but you aren't even fast enough to take advantage of "efficient" supersonic flight. Second, an aircraft that can barely SC at all (best speed of M1.1) means that it can really only do it while straight and level at its ideal altitude, at full (non-augmented) throttle. This isn't a major enabler of anything in combat.

Last but not least, i would like to you guys to wait a few more months and you will have Gripen E flying.

The fundamentals of the design aren't going to change. I am sure Saab's excellent marketers will make the most of it, but given that Gripen NG is merely a heavy update of a Gripen, we know what to expect.

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sigh.

These comparisons of F-35 and Gripen are rather useless, IMHO.

They are, aircraft of two completely different classes, different designs, and also of different cost segments.

In addition, "versus" discussions tend to be not very fruitful.

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No fear fact is here. So far i have seen no figures for f135 fuel consumption. 2 Fuel consumption consists of 3 values Xg/kN·s the first value (weight) is the one that gets better if you improve engine fuel consumption. The second value is the power of the engine. The third value is for counting time.

Say that f135 draws 25g*190kn=4750g(4,75kg/s)/sec*60=285kg per minute. Now checkout if i change that value to gripens engine power 25g*98=2450g(2,45kg)/sec*60=147kg per minute.

Now to the interesting part. Lets assume LM outdid them selves hard when creating f135 and cut the fuel burn by 20% which is a lot, actually almost out of question. 20g*190=3800g(3,8kg)/sec*60=228kg per minute.

With an 20% lowered fuelburn you still have 65% more fuel consumption.

Taking known values for the (Volvo rm12) Gripen c's values, these are the theoretical values 3400kg/72kg/min=47,2 minuter=1180km full dry. WOW ! almost super cruise for the max range of the f-35 (i know, just teoretical without load)

Conclusion A large and strong engine does not automatically get saved by good fuel consumption. And if f-35 use max throttle in dry thrust, it does not super cruise.(remember even if f-35 has exceptionally strong dry trust it can't super cruise).

The range of f-35 is 1200km. And there will be no fast travels in supersonic or with to much load. The point im proving here is that f-35 needs it's large tanks filled to get anywhere at all and whatever you think or wish for can't change that its pure fact and anyone with a calculator can see that.

Knowing gripen demo did mach 1.25 with dry thrust (takes alot) gets me to think flying gripens with 75% trust will be enough with full load and for quite some time over an hour easy on internals.

hopsalot said "Certainly the F-35 is a larger and draggier aircraft... but it also has almost twice the thrust and is carrying its load internally." ??? yes and with thrust comes fuel consumption (remember full dry thrust gets f-35 max to subsonic roof not further.... and to 1.6mach with full burner)

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Will there ever be a Sea Gripen?

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Will there ever be a Sea Gripen?

Nao (in Brazilian).

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latest news from brazil suggest they will do it

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Will there ever be a Sea Gripen?

Almost certainly not. It's only chance it's the Brasilian Navy, who is not swimming in money and has enough funding priorities without having to sponsor the development of a Saab "Kraken".

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latest news from brazil suggest they will do it

As far as I remember, SAAB set up an office in the UK which produced a preliminary design. I guess Brazil could afford to refine the design but I don't think the government will be able to fund development, testing and production for some time.

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"Will there ever be a Sea Gripen?"
Atm Thailand Brazil and India is interested, but it is likely to much money involved (my thoughts).

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"Will there ever be a Sea Gripen?"
Atm Thailand Brazil and India is interested, but it is likely to much money involved (my thoughts).

I think the Thai carrier is designed for STOVL aircraft, unfortunately. India is currently committed to the naval Tejas (in development) so not much chance for a Sea Gripen order... but you never know what will actually happen with India. Brazil's carrier could use a Sea Gripen.

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No fear fact is here. So far i have seen no figures for f135 fuel consumption. 2 Fuel consumption consists of 3 values Xg/kN·s the first value (weight) is the one that gets better if you improve engine fuel consumption. The second value is the power of the engine. The third value is for counting time.

Say that f135 draws 25g*190kn=4750g(4,75kg/s)/sec*60=285kg per minute. Now checkout if i change that value to gripens engine power 25g*98=2450g(2,45kg)/sec*60=147kg per minute.

Now to the interesting part. Lets assume LM outdid them selves hard when creating f135 and cut the fuel burn by 20% which is a lot, actually almost out of question. 20g*190=3800g(3,8kg)/sec*60=228kg per minute.

With an 20% lowered fuelburn you still have 65% more fuel consumption.

You start by saying "fact is here" then proceed to make up a bunch of numbers?

Yes, the F135 is a larger engine with almost twice the thrust of the F414. The F-35 also has substantially more than twice the Gripen's fuel capacity... without knowing the specifics of either aircraft's fuel consumption under cruise conditions all we can say is that the F-35 has a substantial advantage here.

Taking known values for the (Volvo rm12) Gripen c's values, these are the theoretical values 3400kg/72kg/min=47,2 minuter=1180km full dry. WOW ! almost super cruise for the max range of the f-35 (i know, just teoretical without load)

You have a source for a Gripen NG's fuel consumption while "supercruising" at M1.1?

Conclusion A large and strong engine does not automatically get saved by good fuel consumption. And if f-35 use max throttle in dry thrust, it does not super cruise.(remember even if f-35 has exceptionally strong dry trust it can't super cruise).

Conclusion, garbage in, garbage out. BTW, the F-35 does reportedly supercruise:

The F-35, while not technically a "supercruising" aircraft, can maintain Mach 1.2 for a dash of 150 miles without using fuel-gulping afterburners.

"Mach 1.2 is a good speed for you, according to the pilots," O’Bryan said.

The high speed also allows the F-35 to impart more energy to a weapon such as a bomb or missile, meaning the aircraft will be able to "throw" such munitions farther than they could go on their own energy alone.

https://web.archive.org/web/20130112234542/http://www.airforce-magazine.com/MagazineArchive/Pages/2012/November%202012/1112fighter.aspx

The range of f-35 is 1200km. And there will be no fast travels in supersonic or with to much load. The point im proving here is that f-35 needs it's large tanks filled to get anywhere at all and whatever you think or wish for can't change that its pure fact and anyone with a calculator can see that.

1200km? Given that the F-35's combat radius is ~600nm that is a little hard to believe... :rolleyes:

Knowing gripen demo did mach 1.25 with dry thrust (takes alot) gets me to think flying gripens with 75% trust will be enough with full load and for quite some time over an hour easy on internals.

Gripen Demo didn't weight 8,000kg empty, and hitting M1.25 while totally clean isn't really that impressive when you consider that the only thing a Gripen will be doing clean is an air show or running home.

hopsalot said "Certainly the F-35 is a larger and draggier aircraft... but it also has almost twice the thrust and is carrying its load internally." ??? yes and with thrust comes fuel consumption (remember full dry thrust gets f-35 max to subsonic roof not further.... and to 1.6mach with full burner)

Again, even accounting for increased fuel consumption the F-35 has much more fuel than a Gripen NG. You also don't know what the F-35's max sustained speed on dry thrust is but according to the above, it is at least M1.2.

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I think the Thai carrier is designed for STOVL aircraft, unfortunately. India is currently committed to the naval Tejas (in development) so not much chance for a Sea Gripen order... but you never know what will actually happen with India. Brazil's carrier could use a Sea Gripen.

It doesn't have a hope in India either, which has a range of available choices - N-Tejas - light, MiG-29K/Rafale-M - medium, F-35B - heavy. No space for a Sea Gripen.

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Moving towards a PW-229 evolution probably better suited a bigger Gripen than F414, even in an EPE version. Too little, too late IMHO.

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As far as I remember, SAAB set up an office in the UK which produced a preliminary design. I guess Brazil could afford to refine the design but I don't think the government will be able to fund development, testing and production for some time.

no, not for some time, but there would not be any rational plan behind refurbishing the carrier and all the support a/c
without an actual fighter, and what other fighter fit better on sao paulo ?
in fact does any other fighter fit ?

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LCA-N should fit.

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"Will there ever be a Sea Gripen?"
Atm Thailand Brazil and India is interested, but it is likely to much money involved (my thoughts).

Chakri Naruebet is the smallest STOVL carrier ever built. I doubt it'd be possible to operate any CTOL jet fighter from her.
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no, not for some time, but there would not be any rational plan behind refurbishing the carrier and all the support a/c
without an actual fighter, and what other fighter fit better on sao paulo ?
in fact does any other fighter fit ?

Let's see what happens with the French Super Etendards...

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i'm thinking brazilians are aiming to complete the carrier for duty 2030-35,
when Etendards are eligible for elderly home with ICU for each bed

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Aren't the SEM too worn out?

Nic

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I think that might've been about ten years ago... but in any case isn't 2030-35 the projected timeframe for the new carrier? I was referring to potentially operating Super Etendards from Sao Paulo as a way of bridging the gap to the new carrier (and waiting on Sea Gripen or Naval Tejas).