So your source is from 1993, three years before the Gripen A had entered service. It clearly states:
The methodology currently used in Sweden for fatigue
management and verification of airframes is described.
Applications from the new Tighter siicraft JAS39 Gripen
are included in order to illustrate the various concepts
being considered. Additional experience from recent work
on the older fighter 37Viggen is also included to highlight
certain differences in the detail analyses, stemming from
rather different nominal stress levels in the two aircraft.
The present paper discusses the handling of load sequences
and load spectra development, stress analyses and fracture
mechanics analyses, fatigue crack growth modelling,
component and full scale testing, service load monitoring
regarding both the dedicated test aircraft, which is used to
verify basic load assumptions, and also the individual load
tracking programme developed for the new Fighter.
A 1993 article discussing the considerations that must be made for the testing and analysis of fighter aircraft fatigue. Certified mig23m moment.
Flight testing began in 1988, the document is stating the legitimate requirements for what would become the definitive JAS 39A. Saab Aircraft Division in Sweden states 9G as the safe load limit (the number you apply the 1.5x limit to) in any / all documentation.
Allowing the airframe to be stressed up to 12G’s reduces lifespan significantly, and isn’t unusual as I previously stated. Another example is the F/A-18, which is permitted to do so as well.
The Gripen should not be capable of 17G maneuvers in-game as it is currently.
Wing G strength is a combination of weight and g structural limit x 1.5.
So it is not just 9Gx1.5, it is 9Gx1.5 at X weight.
If we dont know the weight at which the structural limit is given, we can not really know what the wing G strenght should be in game. Just an estimate that is not accurate at all.
In game the Gripen does not exceed 14G with full pull of the elevator (likely rounded up from 13.59 but I don’t have the means to check). “17G” is only possible be applying roll to the turn - which is very fucky in War Thunder. For instance, it was possible to get 15G and rip the F-16 by roll-pulling when it still had the limiter compression on last year.
Regarding the structural limits, most NATO aircraft are “safe” for 6G and the computer limits to 9G. They can very briefly bypass the computer for high alpha manuevers but I’m not sure if this is the same as the Gripen’s hardstop. Keeping the computer off in an F-18 would make the plane go dumb and uncontrollable. 9G on these aircraft will likely require heavy inspection and maintenance just as 12G would in the Gripen. Even older aircraft like phantoms (which really shouldn’t be pulling 9G) use the 9G figure in WT - generally not exceeding 13G in game. If a phantom FGR gets an extreme overload warning at 13G in game, Gripen should probably be a fair bit higher than 13.59.
Also the comment about Ikea parts was kinda weird earlier. Deliberately trying to undersell the aircraft’s construction is not great if you’re trying to analyze it objectively.
Edit: Phantom FGR in test flight with ~3 minutes of fuel can hit 14G without applying roll, and does not rip. On empty you get a momentary 15G out of a dive.
You can, in the F/A-18 and F-16, disable the G-Limiter using a paddle switch. How many Gs that actually allows you to go to without the wings failing, I don’t know.
That’s the FCS limit, not the structural limit.
It’s there to keep the pilot alive.
The structural limit of these modern, composite fighter wings is insane.
They can withstand extreme forces but due to delamination from stresses over time have a shorter lifespan than an all metal wing.
The Typhoons wings for example have a service life of 6000 hours which is incredibly short. That’s only 10 hours a week for 12 years. These planes are meant to be in service for 30-35 years…
“They can very briefly bypass the computer for high alpha manuevers but I’m not sure if this is the same as the Gripen’s hardstop.” The paddle switch on the F-18 is what I was referring to here, although the conclusions are the same.
The minimum takeoff weight of the JAS39 is 6700kg (C variant is 6800kg) and the max is 12700kg (C variant is 14000kg). so just going by logic, intuition and those numbers i am guessing the x-axis is times 10³ kg.
yep
I also made some calcs and it is about right that it is weight.
Wing strenght should be increased but also there is a bug where it is not ripping or something I dont understand…
How did the report for ammo change just get implemented (let alone acknowledged)? the report is for E variant. not A/C. the E has had massive changes, its barely the same plane. it even has a bigger airframe and bigger internal fuel tanks.
i did not, but to me that seems like making a report about the Leopard 2A6 using a document on the Leopard 2A7V arguing to use those numbers for armor.
i would be more happy with an estimate compared to using a document on a different plane(in this situation).
i’m not saying that 120 is wrong. i’m saying that we don’t know for sure or have enough sources on it. using data on E is just wrong though.
Edit:
i would just as much argue it is wrong if they used engine data from E to make A/C better.
a lot of the advertised weapons for the Gripen C are based on the fact that it uses NATO standards and that its an open platform
its the only thing i could find. if you want to find a document for the A and C model be my guest. however, the 3 versions should all carry the same gun anways so what difference does it really make.
if anything the E model could have more rounds than the A and C due to a slightly larger airframe
“mouse aim doesn’t use limits for internal SCAS or FBW. It allow using max strength of aircraft.
hard g-limits were included to the SAS damper mode.”
I don’t understand if something was changed by our reports, or if this is describing the current state?
In either case, since 12 g load can be commanded by the pilot, the wings should obviously not rip off at 9g*1.5 in WT. Could someone shed light on this?
That’s not what the document says. Says above 150% of 9G the wing laminates can buckle.
That’s not the case. The pilots are allowed to command 12G, which is closer to the ultimate safety factor limit and reduces airframe lifespan significantly faster. It’s not the “normal” limit.
