The wings will on the other hand have to be redesigned to accomodate the new landing gear. But that would have to be done anyway to be able to handle the increased MTOW.
I don’t think the inner wing structure will change much:
The new main landing gear is attached to a machined steel attachment frame placed on the outside of the wing box
with bolts running through the lower wing skin to a new inner support structure. The exterior attachment frame is
designed to include all mounting points for the main gear strut, folding stay, and retract actuator.
The increased take off weight seems to only need bigger brakes:
The aircraft has a greater MTOW which means that a bigger main wheel and tire are needed to be able to house a
larger, more capable brake.
(AIAA: “Conceptual Design of a New Generation JAS 39 Gripen
Aircraft”)
That concept studie is some years old so it may not be 100% right but on the other hand if the aircraft are going to fly next year there are no time for monumental changes. That’s my two cents anyway.:)
Regards
Swerwe, here’s a sum up:
*Demonstrator aimed mostly at this time towards norwegian and danish fighter competition.
*Formal announcement in 2-3 months.
*Engine is GE F414.
*~40% more fuel.
*Claimed range: Five hour unrefuelled maritime reconnaissance mission or 90-minute CAP to Scotland from norwegian bases.
Almost forgot…found this at militaryphotos.net forum:
http://www.mil.no/multimedia/archive/00089/3_Gripen_Capability_89303a.pdf
Regards, NOAS
Moved this answer from thread “Rafale out of Norway contest” since I thought it would feel more at home under this threadtitle.
Well, I read a little bit more about this whole Gripen N project. And the more I read, the more I like it.
A pair of NSM’s weights roughly 840kg. Even with a heay rack, it remains in a safe region.Except the engine question, I’m nearly convinced this could work well. Now that I like it, I ask myself if this demonstrator I often read about is the same thing as Gripen N ? I mean there are some other things I remember. (NORA, IR-OTIS …)
So.. is it financed ? And is it more then a testbed for improved avionics ?
I´m glad you´re beginning to like it… to bad you are not sitting in the Norwegian goverment. 🙂
I don´t know if Gripen-N is the same as the demonstrator but it would make sense if it is IMHO; using it as a marketing tool/testbed (for all kinds of future development including NEURON input etc.) before and after Norway procurementdecision in 2008. If the timetable allows that is another question.
Neither do I know if it´s financed. IG JAS got an ~(SEK)1 billionorder from FMV(the Defence Matériel Administration) for the next developmentstep (up to 2009) not long ago, but I´m not shure that included any demonstrator (correct me if I´m wrong). It would most likely include some form of NORA radar(see thumbnail), rumour say that South Africa will have IR-OTIS (IRST) but public info have been sparse.
My guess is that final decision on the matter is postponed until after 17 sept. elections. (touch wood) :p
Radar roadmap:
NOAS
first: you have to stengthen the wing/wingbox to withstand that additional stress.
Not shure if that would be needed, the innerpylons are designed to withstand forces of ~4-5G+ with full load. The new maingear should not stress it to much since the moment of force from it (distance from wingattachmentpoints) is fairly short. Landing stress would be bigger but could, I guess, be within stresstolerances or (only) require stronger wingattachment.
second: you have to alter your aiframe. Somewhat different forces and momentums (for which the airframe wasn’t optimized) have to be considered.
Yes, two new ventralpylons would need airframestrenghtening but they are close to CG. Not shure if that would require the hole fuselage to be redesigned as you mention below.
Add to this the now heavier stores on your wing, and you need a redesigned (or completely new) internal wingstructure/center fuselage structure.
The new heavier stores are on the fuselage AFAICS and not on the wing (apart from the added maingear). Gripen can already carry Taurus (1300kg/4G) on it´s inner wingpylons can´t think of anything heavier needed .
SAAB summarise:
Technical benefits of the concept proposal
The gain from using the proposed modification concept for the Gripen a/c described in this paper is twofold:
· It enables fuel to be housed in the previous main gear bays.
· It frees ventral space for extended external weapon/fuel carriage and increases overall carriage flexibility.
Other advantages when assessed against the other modification proposals described in this paper are as follows:
· Increased MTOW
· Very limited impact on airframe.
· Minimal drag in comparison with conventional conformal fuel tanks
· No shift in CG when more internal fuel is added
· Very low shift in CG when new ventral stores are added
· Great overall aircraft development potential
As said before this is only a concept and further studies/tests may complicate things (both tech and costwise) , who knows.
Regarding the engine ,I agree but think the F414 is the frontrunner (even if a EJ would be a preferable alternative) if a new engine is on the table. Remember SAAB has a broad cooperation with GE.
Others have already answered the cheap or not issue better than I can so I skip that. 😉
Of coarse even if these changes could be implemented fairly easy, as SAAB seem to think, (a lot of?)testing would be required. Should be interresting to see if the mentioned “Gripen Demonstrator” have any of these modifications?
NOAS
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