From 14 mins
I think this is something quite a few have seen. It talks about a soft stop of 9G and then a hard stop of 12G. Its finding a Primary source to confirm
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Yes, as a precedent I would want the rip limit to be based off the safety limit. And the overload/paddle limit to be the flight control limit.
ye but that’s a game it’s not real life other wise there’s Tons of other planes that needs to be nerfed your Argument is Pointless in Warthunder,it’s good now there’s a balance between a mid loadout and good performance unlike other planes that have mid performance compared to the gripen (Not compared to Other 3rd gen planes) and very good air to air loadout
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ey back i was test flying the gripen,on avg it can do 14g sustained on high speeds and 14g no sustained on low speeds,min fuel 2 9L’s-Min fuel No missiles so Horayy ig
Same with the F-16 the “UFO” plane.
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https://www.sciencedirect.com/science/article/pii/S1474667015332274
With a pitch stick command to the softstop, the pilot commands load factor to the load factor limit, when the aircraft speed is above corner speed (corner speed
is approximately 600 km/h). Below corner speed a
pilot command to the soft stop means an angle of
attack command to the angle of attack limit. When the
control stick is pushed max forward, the pilot
commands normal load factor to the negative load
factor limit and below corner speed negative angle of
attack to the negative angle of attack limit. The
maximum stick forward position is -7 degrees.
There is a possibility for the pilot to override the soft
stop in an emergency situation and pull the control
stick back to the hard stop and thus get an extra 3g, when aircraft speed is above 600 km/h. This requires
an extra stick force of approximately 135 N.
“In parallel the so-called integration missiles that went to Saab. So they have in Sweden already integrated the missile with the structure of the aircraft, the mechanical integration of the missile with the aircraft and with the avionics, which is very complex on the Gripen. They conducted a series of flight tests where they flew with this missile in extreme angles of attack up to 12G, (12 times standard earth gravity) and up to 13 700m in altitude to ensure the aircraft wasn’t damaged.” The firing of the missile off the aircraft will be tested as a separate activity but it is these days fairly predictable.
That’s a quote from, who was at the time, one of the executives of demel dynamics, who were making the A-Darter with South Africa.
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Being able to pull closer to the ultimate load factor does not increase the ultimate load factor.
According to the Aeronautical Research Institute of Sweden the design limit load factor is 9G with an ultimate safety factor of 150% (1.5x), or 13.5G. This is when the laminates are capable of buckling.
That’s not to mention that the wing and body structure is literally bolted together and made of 7000 series aluminum, as well as steel bathtub fittings from Ikea.
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Your own source says approximate data/design requirements. I can’t look any further because I can’t find anything on Google scholar with that title and author. Must be a high quality source.
It’s in here; and it’s quite thorough about the design requirements. It also says the Viggen’s load factor max is only 1.2x the safe limit (9G?)…
https://apps.dtic.mil/sti/tr/pdf/ADA280273.pdf
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.
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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.
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@CorporalApollo just found a GREAT source for many things including G-limit (both soft 9G and hard 12G) and AoA at 26.
Source;
(https://www.sciencedirect.com/science/article/pii/S1474667015332274)
PDF:
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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.
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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.
For example, this is what you guys should look after.
is the X axis weight in kg?
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…
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“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.
