Can the F-35 match the PAK-FA

The F-35 compared with other modern jets.
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by gta4 » 11 Jun 2019, 15:48

If you look at the lightly loaded F-16-block50 PS chart, that was not 366m/s in 1G straight line flight, but 366m/s in a 5G ascending turn! That is ridiculously high even compared to other high performance jets.

(A lightly loaded Su-27, 18920kg flying weight, can hold less than 250m/s in a 5G ascending turn.
A lightly loaded Mig-29, 12800kg flying weight, can hold 345m/s in 1G straight line climb.
All sources are reliable. I can show them if you want)

And for the F-22 case, if you have an idea of the order of magnitude of these two factors:
1) The percentage of improvement of climb rate at sea level compared to that of 20000ft (Close to the ratio of air density).
2) The percentage of improvement of climb rate when climbing in an inclined trajectory compared to that in pure vertical (90 deg nose up).

You will understand 312m/s in 90deg nose up at 20000 ft means F-22 is unrivaled.
Last edited by gta4 on 12 Jun 2019, 00:55, edited 1 time in total.


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by disconnectedradical » 11 Jun 2019, 16:01

Also if you look at F-16 Block 50 acceleration, you see that when clean, 0 drag index, and only 24,000 lb gross weight, from Mach 0.8-1.5 at 30,000 ft it's 47 seconds to it's even better than F-22. If I want to make ultimate dogfight machine, I would take Viper airframe, give it F110-GE-132 engines with 32,000 lb thrust and AVEN thrust vectoring like on F-16 VISTA and just pair of wingtip AIM-9X. When clean this thing will out turn and out accelerate anything in the air. But I will never take this thing to combat over F-22 or F-35 because it will never make it to the merge.

EDIT: I misread the chart, it's 24,000 gross weight, not 22,000.
Last edited by disconnectedradical on 11 Jun 2019, 19:37, edited 2 times in total.


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by gta4 » 11 Jun 2019, 16:03

The SEP in an ascending turn is an important indicator of how well the jet performs in the vertical.
If the jet has good SEP in high G ascending turn, it means it can even accelerate when pulled up. Potentially it can pull infinite loops while its adversary stalls at the peak of the loop.

F-15/16 are very good at vertical maneuvers. They used this technique to beat the mighty X-31 in 1994. I won't be surprised if they beat flanker/fulcrum in the same way, given that X-31 is much more maneuverable than flanker/fulcrum.


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by gta4 » 11 Jun 2019, 16:05

disconnectedradical wrote:Also if you look at F-16 Block 50 acceleration, you see that when clean, 0 drag index, and only 22,000 lb gross weight, from Mach 0.8-1.5 at 30,000 ft it's 47 seconds to it's even better than F-22. If I want to make ultimate dogfight machine, I would take Viper airframe, give it F110-GE-132 engines with 32,000 lb thrust and AVEN thrust vectoring like on F-16 VISTA and just pair of wingtip AIM-9X. When clean this thing will out turn and out accelerate anything in the air. But I will never take this thing to combat over F-22 because it will never make it to the merge.


Sorry man viper's 46 sec is achieved with 0 missiles while F-22's 50 sec is achieved with 6 amraams+2aim9s. I still think the advantage goes to the Raptor.


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by disconnectedradical » 11 Jun 2019, 16:08

gta4 wrote:
disconnectedradical wrote:Also if you look at F-16 Block 50 acceleration, you see that when clean, 0 drag index, and only 22,000 lb gross weight, from Mach 0.8-1.5 at 30,000 ft it's 47 seconds to it's even better than F-22. If I want to make ultimate dogfight machine, I would take Viper airframe, give it F110-GE-132 engines with 32,000 lb thrust and AVEN thrust vectoring like on F-16 VISTA and just pair of wingtip AIM-9X. When clean this thing will out turn and out accelerate anything in the air. But I will never take this thing to combat over F-22 because it will never make it to the merge.


Sorry man viper's 46 sec is achieved with 0 missiles while F-22's 50 sec is achieved with 6 amraams+2aim9s. I still think the advantage goes to the Raptor.


Technically Viper can do it with 2 wingtip AIM-9 or AIM-120 since they add 0 drag index. Still doesn't make a difference though, any remotely realistic combat load, even for A2A, will still be F-22 advantage especially since F-16 will never make it to the merge.


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by sprstdlyscottsmn » 11 Jun 2019, 16:57

At that weight the Viper is also Bingo Fuel and won't be using the AB unless it is only to allow for ejection. 22,000lb is a whopping 3,000lb fuel if unarmed, and as two AIM-120s are ~700lb (and it would never be DI 0 even if it jettisoned all loads, pylons would remain and they have both weight and drag) that leaves only 2,300lb fuel. With a 1,000lb reserve that leaves 1,300lb for transit. Even at a fuel sipping .2nm/lb he needs to be less than 260nm from home base (not unreasonable)
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by gta4 » 11 Jun 2019, 17:00

sprstdlyscottsmn wrote:At that weight the Viper is also Bingo Fuel and won't be using the AB unless it is only to allow for ejection. 22,000lb is a whopping 3,000lb fuel if unarmed, and as two AIM-120s are ~700lb (and it would never be DI 0 even if it jettisoned all loads, pylons would remain and they have both weight and drag) that leaves only 2,300lb fuel. With a 1,000lb reserve that leaves 1,300lb for transit. Even at a fuel sipping .2nm/lb he needs to be less than 260nm from home base (not unreasonable)


That is why I was also using clean/bingo fuel loadout of SU-27/Mig-29 to make a fair comparison.

A lightly loaded F-16, 22000lbs flying weight, can hold 366m/s in a 5G ascending turn.
A lightly loaded Su-27, 18920kg flying weight, can hold less than 250m/s in a 5G ascending turn.
A lightly loaded Mig-29, 12800kg flying weight, can hold 345m/s in 1G straight line climb.


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by disconnectedradical » 11 Jun 2019, 18:07

sprstdlyscottsmn wrote:At that weight the Viper is also Bingo Fuel and won't be using the AB unless it is only to allow for ejection. 22,000lb is a whopping 3,000lb fuel if unarmed, and as two AIM-120s are ~700lb (and it would never be DI 0 even if it jettisoned all loads, pylons would remain and they have both weight and drag) that leaves only 2,300lb fuel. With a 1,000lb reserve that leaves 1,300lb for transit. Even at a fuel sipping .2nm/lb he needs to be less than 260nm from home base (not unreasonable)


Yes, like I said it's a useless load, only enough to take off, do the acceleration run, and return to base. Again, here I'm assuming that not even pylons are attached, only wingtip AIM-9 on station 1 and 9.

Point is, F-22 can compete with clean F-16, while also having stealth and VLO and avionics that won't even fit in Viper unless it has a dorsal hump. That's why I don't get obsession with kinematics and trying to think F-22 can do impossible things.


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by sprstdlyscottsmn » 11 Jun 2019, 19:13

Okay, this made for a fun thought experiment. Pulling up the HAF-1 and doing some interpolation I get a 0.8-1.5M acceleration time of just under 43s for the DI0 22,000lb plane. For a DI 50 26,000lb plane (more representative of the Raptor configuration used for the speed run) I get 64 seconds. That is screaming fast, even if less so than the F-22.

And remember, these are level accelerations and are not representative of a Rutowski profile. These are useful to compare relative power under these conditions only.

Now, the sea level loaded climb of the DI 0 22k plane. 0.9M is ~1000ft/s at sea level standard. The Airshow-16 can sustain a 5G pull with that positive Ps. The radius of that pull is ~5,000ft. Meaning it can go from level to a 5G pull into the vertical without losing speed and will exit that pull 5,000ft up.

Going to the 5,000ft chart, I extrapolated based on the Ps lines shown (and not shown, this tells me that even at zero G there is no 1200ft/s line) that at 0G the Airshow-16 can sit vertically at 0.9M and accelerate with a net acceleration of ~0.2G.
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by mixelflick » 11 Jun 2019, 19:14

The SU-57 may be the one aircraft capable of beating Raptor acceleration, but it needs those new engines to do it.

The Russians don't call it "the needle" for nothing. It's built for acceleration and so called, "supermaneuverability". Because it won't be as stealthy, they need to focus more on kinematics. The only question in my mind is will the Raptor upgrades keep it ahead of the threat.

"Supermaneuverability" or not, the onus is on the SU-57. Great potential, but potential unrealized is... meaningless. I think like the SU-27 they'll eventually succeed, albeit it'll be in service in numbers smaller than the SU-35 (currently 80). There's a reason they're still building SU-35's.. Going to take time and perhaps a lot of it for SU-57 to mature. Even then, I think 80 machines is a stretch.

Unless those foreign orders come in from the UAE, Turkey, Vietnam etc., subsidizing it may prove impossible. They need those foreign orders to make it affordable on their end..


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by knowan » 11 Jun 2019, 22:24

gta4 wrote:And if you compare the kinematic performance (acceleration, rate of climb...) of Su-35's official brochure and compare it with Fulcrum-A's flight manual, it is not hard to find that Su-35 is out-performed by Fulcrum-A.


After seeing how much the performance of the Su-35 is hyped up by Russian sources, that is highly amusing.


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by gta4 » 12 Jun 2019, 01:26

sprstdlyscottsmn wrote:Okay, this made for a fun thought experiment. Pulling up the HAF-1 and doing some interpolation I get a 0.8-1.5M acceleration time of just under 43s for the DI0 22,000lb plane. For a DI 50 26,000lb plane (more representative of the Raptor configuration used for the speed run) I get 64 seconds. That is screaming fast, even if less so than the F-22.

And remember, these are level accelerations and are not representative of a Rutowski profile. These are useful to compare relative power under these conditions only.

Now, the sea level loaded climb of the DI 0 22k plane. 0.9M is ~1000ft/s at sea level standard. The Airshow-16 can sustain a 5G pull with that positive Ps. The radius of that pull is ~5,000ft. Meaning it can go from level to a 5G pull into the vertical without losing speed and will exit that pull 5,000ft up.

Going to the 5,000ft chart, I extrapolated based on the Ps lines shown (and not shown, this tells me that even at zero G there is no 1200ft/s line) that at 0G the Airshow-16 can sit vertically at 0.9M and accelerate with a net acceleration of ~0.2G.


I think you are checking block52 chart. The block 50 chart is more amazing


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by sprstdlyscottsmn » 12 Jun 2019, 01:51

I was checking the GE motor. Let me clarify, 0.9M is a nose forward speed of 1000ft/s. This is what told me it could be vertical at 5G.
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by fidgetspinner » 12 Jun 2019, 02:36

"The SU-57 may be the one aircraft capable of beating Raptor acceleration, but it needs those new engines to do it."

Are you referring to the super cruise speeds than yes that would be a possibility but no sources yet to say what the new engine cruise speeds can attain. I am more interested in how much the range improvement would be on the aircraft than sources saying 3,500kms for max range regarding the old engines.

"Because it won't be as stealthy, they need to focus more on kinematics"

As long as your not one of those users that think EPR and RCS are the same thing than your fine with me. We ran into such users at key forum pub awhile ago.


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