SAAB Gripen and Gripen NG thread #4

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15 years 9 months

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Well that fact sheet is dated March 2016. On the site itself, they don't mention supercruise, among other things. It's probably best to wait and see what happens when they open up the flight envelope.

This was reported after the first supersonic test flight, last year:

Aircraft 39-8 was flown at supersonic speed for the first time on 18 October, with test pilot Marcus Wandt describing its performance as "very smooth" during a sortie flown over the Baltic Sea. "The aircraft sustained supersonic speed for a number of minutes, whilst carrying out manoeuvres," the company says.

Powered by a GE Aviation F414 engine, the Gripen E will be capable of "supercruise" performance: sustaining supersonic flight without the use of its afterburner.

https://www.flightglobal.com/news/articles/supersonic-test-keeps-gripen-e-on-target-442657/

Nevertheless the test flight program has not yet concluded so perhaps it is prudent to wait before drawing any final conclusion. However based on the above I would conclude that it still seems possible that Gripen E will be able to supercruise. For how long, well that is another question!

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Well the Wikipedia page says M1.25 but I don't know if I would think that is the definitive source.

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Wiki says M1.1 for the E model with A2A.

The JAS 39E and F variants under development are to adopt the F414G powerplant, a variant of the General Electric F414. The F414G can produce 20% greater thrust than the current RM12 engine, enabling the Gripen to supercruise (maintain speed beyond the sound barrier without the use of afterburners) at a speed of Mach 1.1 while carrying an air-to-air combat payload.[66] In 2010, Volvo Aero stated it was capable of further developing its RM12 engine to better match the performance of the F414G, and claimed that developing the RM12 would be a less expensive option.[138] Prior to Saab's selection of the F414G, the Eurojet EJ200 had also been under consideration for the Gripen; proposed implementations included the use of thrust vectoring.[139]

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Jettisoning the 4 AMRAAMs it could reach M1.2 possibly M1.25 on SC.

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Ahh sorry you are correct.

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The source from that is a 2008 article saying that the Gripen NG will be able to supercruise with the new engine, not that it's actually achieved that. The plane has changed since then.

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15 years 2 months

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You are using Total Thrust to get to that "20% more than the RM12" figure which negates super-cruise. Looking at the "Dry Thrust" numbers, the F414G only has 7% more than the RM12, not 20%.

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@ Spud no it’s about 20% 2,200lbs more intermediate thrust (Wikipedia thrust figures are b.s., I posted F414 thrust figures on previous page)

@ pants and topspeed- really? Wikipedia says? Well, then it must be true.......

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Thrust at altitude is what matters.

Using SLS thrust provided by engine manufacturers in a test stand does not give insight into thrust at altitude.

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Which is why I said that wikipedia isn't a definitive source.

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Thrust at altitude is what matters.

Using SLS thrust provided by engine manufacturers in a test stand does not give insight into thrust at altitude.

Exactly, that was one example I broke down on previous page using the F100.

The F414 is a low bypass turbofan though, and flight thrust at higher altitudes likely doesn’t drop off as severely as previous generation turbofans (but still too many unknown variables such as inlet performance, drag). Remain sceptical of Gripen E possessing usable supercruise.

Yes the NG reached Mach 1.2 (in a clean configuration). And while the inlets on the NG were not optimized for the F414, it also didn’t have the fuselage stretch and widening, increased wing area, wingtip ECM, weight gain. Parasitic drag increased, profile drag, and likely trim drag with a higher GW. If the test program reveals the Gripen E can supercruise at Mach 1.2 or above when armed with more that two missiles, I’ll be happy to admit I was wrong (I think it more likely that it can slightly exceed Mach 1 when light on dry thrust, just like the “C”)

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A main problem is that the GE site only mentions the "Total Thrust" and not installed thrust or dry thrust.

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@Spud, RAND did a study on turbofan acquisition that had the thrust figures directly from OEM’s and USAF. Also, War college paper on the Super Hornet had accurate thrust figures.

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Yes the NG reached Mach 1.2 (in a clean configuration). And while the inlets on the NG were not optimized for the F414, it also didn’t have the fuselage stretch and widening, increased wing area, wingtip ECM, weight gain. Parasitic drag increased, profile drag, and likely trim drag with a higher GW. If the test program reveals the Gripen E can supercruise at Mach 1.2 or above when armed with more that two missiles, I’ll be happy to admit I was wrong (I think it more likely that it can slightly exceed Mach 1 when light on dry thrust, just like the “C”)

Cd may have dropped..increased parasitic drag is next to zero..in any meaningfull aspect.

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http://www.deagel.com/news/Leonardo-Launches-Grifo-E-AESA-Multi-functional-Radar_n000017937.aspx

"Grifo-E makes use of Leonardo's leading Active Electronically Scanned Array (AESA) technology, also known as 'E-Scan', hence the '-E' suffix. AESA technology involves a matrix of hundreds of tiny radar modules being used to 'steer' an electronic beam, rather than the radar physically moving to point a beam at a target. This means the beam can be moved around extremely quickly, allowing the radar to perform multiple tasks simultaneously. Because the building blocks of the Grifo-E are mature, proven technologies owned by Leonardo, the Company has been able to invest in developing a range of advanced new modes for the radar, fully exploiting the capabilities of AESA, a multi-channel receiver and multi-core processing units."

The SU-35 used hydraulic actuator for a 240 degree beam mechanical steer. Guys which would be a better choice having a 240 degree azimuth by steering a beam extremely quickly or having 1536 modules having coverage for the 120 degree azimuth and having 358 modules for the sides to provide the other 240 degree coverage?

Just for my own curiosity I am wondering rather if this technology was available at the time for Russia to implement on the SU-57 because they went from mechanical steering to more modules focused on the front than the sides, While Leonardo says the beam moves at a rapid speed to cover a wider beam. If Russia had this option available would they have ditched the 358 side radar arrays if a 240 degree radar beam azimuth with electronic steering was available? It seems that SAAB likes to implement a wide radar beam

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Just for my own curiosity I am wondering rather if this technology was available at the time for Russia to implement on the SU-57 because they went from mechanical steering to more modules focused on the front than the sides, While Leonardo says the beam moves at a rapid speed to cover a wider beam. If Russia had this option available would they have ditched the 358 side radar arrays if a 240 degree radar beam azimuth with electronic steering was available? It seems that SAAB likes to implement a wide radar beam

The Su-57 approach is superior. Mainly because it does not introduce mechanical element. Something which any ESA designer trying to avoid. and it provide true coverage. The swashplate or mechanical steering does provide increased coverage in one side but sacrifice the other, pretty much like you turning your head left and right. You turn right, you cover entire field on the right but not on the left.

The downside is of course the array costs and increased cooling and power supply requirement as each array face may need their own set.

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What you just said made no sense.
ESA radar with Gimbals one way or another has been on the market for a loong time now.

The Pros about using Gimbals on Radar Array, you can scan an entire sector to your left(or right), while your desired heading 120-140 deg off.
Exellent example, you are fencing a airspace border. You know one side is friendly, other side not friendly.

In my mind better to have Gimbals.
The Gimbals adds weight. But i don,t think they add downtime. There is other problems, such as cooling problem and software glitch.

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And 2 aircraft + data link = full coverage for both aircraft 100% of the time. Both approach have obviously their forces and weaknesses.

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What you just said made no sense.
ESA radar with Gimbals one way or another has been on the market for a loong time now.

If it fails ? you lost entire coverage on one side. and why they need gimbal in the first place ? To reduce cost and further cooling/integration burden of having multiple array. Remember that AESA radar is advertised for being reliable because it can be solid state (NO moving parts), or simply to try bear full gain of antenna off boresight.


The Pros about using Gimbals on Radar Array, you can scan an entire sector to your left(or right), while your desired heading 120-140 deg off.
Exellent example, you are fencing a airspace border. You know one side is friendly, other side not friendly.

This can be done, even better with multiple array face. Why do you think we have ground based radars like AEGIS having multiple faces covering 360 deg ? and let's look at APAR, then Australian does it with 6 faces with their future Type-26 frigate and Anzac.