SAAF JAS-39C Technical Data and Discussion

Why is Ziggy’s coment flagged lol. thats a quite clear abuse of the flagging system.

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Weird huh. I will ask Stona or smin about it. No worries. We move on.

Developer said nothing is wrong with the canards. Chalk it down as a win for the Gripen and the UK and Swede tech tree.

Let’s hope there is another gross misinterpretation regarding the thrust. I do not think the thrust is overperforming either imo.

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Well hes using the wrong engine and data from said engine for a start so

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We’ve gone over this already and it warrants a change. The -402 should have more thrust than the RM12 and peaks at ~19,340 lb-f… not to mention that since both engines use practically the same design and margins with only an increase in RPM / Temp limits for -402 model the RM12 should have a similar thrust curve.

Or am I wrong on this one? @MAV_JK

The -402 model solved the thrust drop-off beyond 0.8 mach for the most part… it doesn’t fall off a cliff at least… but it doesn’t INCREASE further.

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Im not going to argue with someone like you.

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here we go again

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Uninstalled thrust =/= installed thrust. I am simply pointing out the optimal thrust curves for the engine available per public sources. There is a rather large discrepancy by ~25% at speeds above 0.9 mach with what is seen in-game. The performance exceeds that of the -IN20 model of the engine…

General Electric’s website no longer includes the -400 variant in the F404 family PDF. So how did you still manage to bring up the charts for the -400 variant?

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There are a number of sources;
F404 Report
GAO Report
QNEP Thesis

Screenshot_20231222-174149_Drive (1)

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from NASA test
so how did you find the F400-400 22000 lbf variant ?

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This is from a 1984 document projecting the potential improvements to the F404 engine. The -402 is likely what is known as “Growth 2” and makes improvements over the RM12 as I’ve said already. It was first installed on the F/A-18’s in the early to mid 90s.

The RM12 was flying in the Gripen from '88.

Since the -402 shows an improvement over RM12, and significantly exceeds its’ performance in-game we can see there is a discrepancy. It’s rather simple stuff.

So, why use the -400 variant for comparison ?
because developer use the -402 variant to reject your previous report?

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It is a basis for discussion, it shows the thrust curve of the engine which is temperature limited as stated. From there we can show the improved core model -402 which has higher temp limits than the RM12. It solved the high speed thrust drop-off according to GAO.

What I am asking is that the thrust be reduced to the amount of the improved -402 model… otherwise known as the “enhanced performance engine” model… this only makes sense.

Currently the performance of the RM12 is well above what would be expected even for the -IN20 as stated. It should technically have lower installed thrust than the -402 model since it does not feature the same upgrades… and as GE stated… none of them are flow limited in any way.

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restored :)

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No one knows the actual channel loss for the RM12 and -402 variants, but the developer has already answered you

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We don’t see any reason to change something for engine thrust now, we don’t have any of 402 or RM12 exact gross thrust plots, and these sources are too questionable. Leaving this unchanged.
Sea level from Mach .5 to 1.1 is ~35s, which approximately matches Saab ASWT article of 30s

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You’re very insistent on not acknowledging what I’ve said. Your argument is becoming circular… just wait for the new report.

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better than while looking at your presentation of strange data

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RM12 thrust report

Well. If you accept that trying to beat 15/16 in one circle is the shortest way to the hangar and pay attention to the sustained turn, then it looks interesting.
Gripen accelerates from ~19 deg/s (~1300 kg of fuel with no BOL and 2 aim-9) to 22 deg/s (near zero fuel with no BOL and 2 aim-9) on ~300 knots.

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There is only one “but”. Tornado does the same thing. But on ~400 knots. I couldn’t slow it down to less than 350 knots in a sustained turn.

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Of course, provided that we turn a blind eye to the Tornado’s fuel consumption of 650-670 kg/s, compared to the Gripen’s consumption of approximately 230-240 kg/s.

So, in SB it’s look promising with 20min fuel+droptank, but in RB you don’t even need to turn much, so difference not much.

Oh, yeah, and preflaring it’s bless aganist pov-defended Fox-2 :D