Gripen NG (Next Generation)

Westpoint321 · **Joined:** 16 Sep 2007, 00:24 **Posts:** 123

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Sweden to Modernize its JAS-39 Gripen Fleet

It has been a good couple of days for Saab. Fresh off a come-from-behind win in Thailand, the firm has signed a SEK 3.9 billion ($600 million) contract with the Swedish Defence Material Administration (FMV) to upgrade 31 Swedish Air Force JAS-39 A/B Gripens to the very latest JAS-39 C/D standard.

The FMV has also given the go ahead for the next-generation 'Gripen Demo' variant, whose development program includes the development of a new Gripen test flying platform and a new Gripen avionics set. FMV Gripen Demo funds in this contract can be added to an earlier SEK 1 billion (currently $150 million) award, as an offset to Saab's participation in the European nEUROn unmanned fighter program.

Gripen Demo will be a heavier aircraft (empty weight adds 300 kg to 8,100 kg, max. takeoff weight rises from 14,000 kg to 16,000 kg) with increased external and internal fuel capacity (internal fuel rises 38%, and…) and an increase from 8 to 10 weapon/fuel pylons. To offset this extra weight, Gripen Demo will use a higher-thrust GE/Volvo F414 engine variant, replacing the GE/Volvo F404 variant in current aircraft and giving the aircraft a 25%-35% power boost. Other improvements include an next-generation AESA radar (probably drawing on Ericsson's "Nora" project), along with improved computing and avionics overall, including satellite communication, Link 16 capability added to the Gripen's existing datalink, and improved electronic warfare via jammer pod integration and other measures. Gripen Demo's corporate participants include Saab, General Electric together with Volvo (F414 engine), Honeywell, Rockwell Collins, APPH, Martin-Baker and Terma.

Gripen Demo is designed to pave the way for future variants (JAS-39 E/F, DK, N et. al.). A next-generation Gripen is critical to the long-term viability and competitiveness of Sweden's fighter fleet, and also to a number of contracts Saab is fighting for abroad. Norway signed a $25 million Letter of Agreement regarding Gripen Demo in April 2007, for instance, as part of the 3-way competition (F-35, JAS-39, Eurofighter) to replace its F-16s.

The Official gripen websites image gallery seems to be down or something, it gives me an error the whole time, is it doing that with you guys :?:

This upgrade will eliminate or decrease the disadvantages of the Gripen, making a brilliant plane into an excellent aircraft fit for any Air force. :partyman:

Robban · **Joined:** 27 Mar 2006, 12:11 **Posts:** 106

Westpoint321 wrote:

Quote:

The Official gripen websites image gallery seems to be down or something, it gives me an error the whole time, is it doing that with you guys :?:

I'm not able to download the latest Hungarian Gripen photos, but otherwise the site works for me.

A demonstrator for the JAS 39E/F or NG will fly in 2008. 39803 has been modified and fitted with the new and stronger landing gear, and it also has been fitted with the F414G. An additional 2 tons of thrust to a small and light airframe should give a good boost to its already excellent acceleration, as well as improving its climb rate and STR.

I'm curious about those "saddle bags" housing the new landing gear. I wonder how much they affect performance? Granted the Gripen has extremely low drag to begin with but still? I'm guessing they offer lower drag than an external drop tank? They do look quite similar to the ones on the F-35.
It's funny though, all those pics showing an insane amount of weapons under its wings. I don't think it will ever fly with such loads when in service, or in combat, if it should come to that. It's probably just a PR load out.

Westpoint321 · **Joined:** 16 Sep 2007, 00:24 **Posts:** 123

A picture of the F414G :

koffiepit · **Posted:** 20 Dec 2007, 12:36

Based on SAAB's company information supplied elsewhere in this discussion, I ventured to do a comparative analysis on the sustained turning performance between the NG-model and the C-model. It seems that mainly due to the heavier structure and fuel weight that will under most circumstances be lugged around by the NG-model and to a lesser extend due to the fact that the wingspan remains constant there won't be an actual improvement in the sustained turning ability but, nor will their be a noticeable deterioration mainly due to the larger engine thrust. This comparison is based on the method suggested by Deltawingman in a different discussion threat on this forum. My apologies if I got it wrong.

I suspect that the actual worrying factor that will be rectified by the NG-model is the range issue and the loiter time once on station. This is, IMO, what the SAAF actually need in Africa. Another improvement will be that the T/W-ratio seems to be better in the NG-model compared with the C-model which means improved acceleration and climbing performance.

The C-model's airframe seems to be very well shaped in terms of the Area rule which may make it quite slippery in the supersonic flight regime. This is just a guess based on what one can deduce from photo's. The NG-model seems a bit more bulky which may lead to more drag all round which will impact on acceleration and eat into the range that might otherwise have been attained. Again, this is all guesswork and speculation. Maybe others could give more firm information on these aspects.

Here are my calculations:
C-model N-model Load factor ratio: N-model/C-model
We [kg] 6800 7100
We [N] 66708 69651
MTOW [kg] 14000 16000
MTOW [N] 137340 156960
Payload [kg] 5000 6000
Payload [N] 49050 58860
Fuel Fraction0 0.27 0.35* *based on the fuel weight calculated below and the empty weight
Fuel Weight [N]18011 24855** **based on the 138% more fuel as stated by the brochure above
b [m] 8.4 8.4
T [lbf] 18000 22000
T [N] 80068 97861
T/W mtow 0.583 0.6235
b2/W mtow 0.000513761 0.000449541
b2T/W2 mtow 0.000299518 0.000280278 0.935763889
T/W .5payload0.877620992 0.987685671
b2/W .5payload0.000773404 0.000712145
b2T/W2 .5payload0.000678756 0.000703375 1.036270954

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