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Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 11 Aug 2019, 04:36
by gta4
spazsinbad wrote:You must be kidding and 'how do you know this 'fact'?' Stealth coatings may be damaged on an F-22 but that does not mean it is not well maintained otherwise - especially if it is FLYING in an airshow. The last thing anyone needs is a crash.
"...Some of them [USAF airshow aircraft] are not properly maintained..."


I mean some 4th Gen. such as F15/16.
I checked the tail number of the airshow aircraft from Paris le bourget 2005 to Farnborough 2010, they were all actual combat aircraft in service. Some cosmetics were in bad shape, compared to the Russian stripped-off Su-27P airshow variant.

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 11 Aug 2019, 07:01
by sprstdlyscottsmn
I think what he is trying to highlight is that the Russian have a history of their airshow planes being purpose configured thoroughbreds while the USAF uses workhorses.

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 11 Aug 2019, 09:23
by southerncross
gta4 wrote:That is 50% of take-off fuel (50% * 6000kg, give or take), not 50% of full internal fuel (50% * 11500kg)

You have a point, this seems actually supported by the data found at KnAAPO:

"Время разгона на высоте 1000 м при остатке топлива 50% от нормальной заправки, сек: "
"Acceleration time at an altitude of 1000 m with the remaining fuel 50% of the normal refuelling, seconds: "

http://www.knaapo.ru/products/su-35/

What we don't know and are assuming is that normal take-off weight is 50% internal fuel, since no empty weight is stated. I mean, what you say makes sense but I have not seen a hard proof of it. Small deviations should not change things too much though.

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 11 Aug 2019, 11:17
by gta4
southerncross wrote:
gta4 wrote:That is 50% of take-off fuel (50% * 6000kg, give or take), not 50% of full internal fuel (50% * 11500kg)

You have a point, this seems actually supported by the data found at KnAAPO:

"Время разгона на высоте 1000 м при остатке топлива 50% от нормальной заправки, сек: "
"Acceleration time at an altitude of 1000 m with the remaining fuel 50% of the normal refuelling, seconds: "

http://www.knaapo.ru/products/su-35/

What we don't know and are assuming is that normal take-off weight is 50% internal fuel, since no empty weight is stated. I mean, what you say makes sense but I have not seen a hard proof of it. Small deviations should not change things too much though.


You are right. Su-35's data is vague, but Su-27's data is clear. Just compare F-35 with Su-27 and that is enough, because out-flying Su-27 is no small feat at all. That alone could prove F-35's flight performance is not "3rd Gen. level", but "at least on par with ordinary 4th Gen."

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 11 Aug 2019, 11:39
by gta4
I heard in Vietnam/Indonesia they use the following formula to rate fighter jets' flight performance:

Max instantaneous G (maxed out at 9) + Max sustained G (maxed out at 9) + Max sea level SEP / (300m/s) * 9.

Here are scores of some jets based on flight manual (clean, light fuel configuration)

Su-27: 8+8+(310/300)*9=25.3

Mig-29A: 9+9+(345/300)*9=28.35

F-15C: 9+9+(350/300)*9=28.5 (the SEP value comes from http://www.alternatewars.com/SAC/F-15C_ ... y_1992.pdf , 67050dt/sec with 3 pylons, so in clean configuration it is safe to assume 350m/s)

F-16C-50: 9+9+(370/300)*9=29.1 (370 may be underestimated because that is the SEP in a 4~5G ascending turn instead of straight line flight)

Mirage-2000-5: 9+7+(284/300)*9=24.52 (Data from Dassult airshow brochure)

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 11 Aug 2019, 16:08
by f-16adf
Don't know what Block F-16C in that doc they are referencing. However, if you load up the Block 50 with full internal fuel and 2 Aim-120's (and estimate it for 15K ft) it has better acceleration than the posted F-16 number.

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 12 Aug 2019, 08:41
by gta4
f-16adf wrote:Don't know what Block F-16C in that doc they are referencing. However, if you load up the Block 50 with full internal fuel and 2 Aim-120's (and estimate it for 15K ft) it has better acceleration than the posted F-16 number.


That SEP unit is in Meter/Second instead of Feet/Second. To make the conversion easier, 1000ft/second = 305m/second

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 14 Aug 2019, 23:32
by sprstdlyscottsmn
After spending some time mulling this over I have decided I will add several more things to the missile section, including estimates for the rocket motor size/Isp, max off boresight capability, and ability to engage targets at that degree of boresight. For full datalink over the shoulder capable missiles that will be a target 180 deg behind them, with max and min ranges. To be included with the missile data is turn rate and radius at optimum q, M2, and M1.

Also I will add a bit more aircraft info for weights, wing areas, CL curves used, and things like that. Perhaps Max ranges for engaging a "Foxbat" target flying towards/away from the fighter at 2.5M and 75,000ft to show the amount of KE boost the plane can give to the missile.

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 15 Aug 2019, 05:56
by garrya
sprstdlyscottsmn wrote:Also I will add a bit more aircraft info for weights, wing areas, CL curves used, and things like that. Perhaps Max ranges for engaging a "Foxbat" target flying towards/away from the fighter at 2.5M and 75,000ft to show the amount of KE boost the plane can give to the missile.

This will be great :drool:

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 15 Aug 2019, 17:12
by sprstdlyscottsmn
unformatted (thanks F-16.net) examples of the updates to Missile and Plane data.

AIM-120D
The AIM-120D is the latest version of the AMRAAM line which combined advanced 2-way datalinking, improved ECCM, improved range through optimized trajectory and guidance, and improved HOBS while maintaining a small package in both weight and diameter.
Motor:
Boost: 8s @ 4470lbt
Sustain: N/A
Loft: 25 deg
Rated Range: M2 M1 Min:
Head on: 59nm 80nm
Nom Bore (60deg): 53.9nm 72.7nm
Max Bore (180deg): 34nm 52nm 2nm
Turn:
Max G: 44 (est)
Speed at FL360: 2.06M
Perf at speed Opt M2 M1
Rate: 41.5dps 41dps 22.9dps
RadiusL 2,700ft 2,760ft 2,570ft
Warhead: 18.1kg.
100% dam distance: 4m
50% dam distance: 11m
25% dam distance: 19.5m
10% dam distance: 32m
ECCM: 7 (host radar with two-way datalink)
Nominal Pk: 78%
Total Score: 8.7


1.4.1 F-15SA
Empty Weight: 34,200lb (F-15E no CFT)
Internal Fuel: 12,915lb (F-15E no CFT)
MGTOW: 81,000lb
Max Fuel Payload Remaining: 6,474lb
Typical Fuel Payload Remaining: 11,211lb
Maneuver Weight: 68,000lb
G max: 9
Ref Wing Area: 608
CLmax: 1.64 @ 40oAoA (NASA test)
AoAmax: 40o
Installed Mil Thrust: 26,520lbt
Installed Max Thrust: 46,180lbt
Max Range Launch against a Foxbat AIM-120D fired from 1.4M @ FL490
Head on: 197nm (124nm flight) assuming limited to 180s on-board power
Tail chase: 48nm (120nm flight)

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 16 Aug 2019, 04:34
by garrya
sprstdlyscottsmn wrote:unformatted (thanks F-16.net) examples of the updates to Missile and Plane data.

AIM-120D
The AIM-120D is the latest version of the AMRAAM line which combined advanced 2-way datalinking, improved ECCM, improved range through optimized trajectory and guidance, and improved HOBS while maintaining a small package in both weight and diameter.
Motor:
Boost: 8s @ 4470lbt
Sustain: N/A
Loft: 25 deg
Rated Range: M2 M1 Min:
Head on: 59nm 80nm
Nom Bore (60deg): 53.9nm 72.7nm
Max Bore (180deg): 34nm 52nm 2nm
Turn:
Max G: 44 (est)
Speed at FL360: 2.06M
Perf at speed Opt M2 M1
Rate: 41.5dps 41dps 22.9dps
RadiusL 2,700ft 2,760ft 2,570ft
Warhead: 18.1kg.
100% dam distance: 4m
50% dam distance: 11m
25% dam distance: 19.5m
10% dam distance: 32m
ECCM: 7 (host radar with two-way datalink)
Nominal Pk: 78%
Total Score: 8.7


1.4.1 F-15SA
Empty Weight: 34,200lb (F-15E no CFT)
Internal Fuel: 12,915lb (F-15E no CFT)
MGTOW: 81,000lb
Max Fuel Payload Remaining: 6,474lb
Typical Fuel Payload Remaining: 11,211lb
Maneuver Weight: 68,000lb
G max: 9
Ref Wing Area: 608
CLmax: 1.64 @ 40oAoA (NASA test)
AoAmax: 40o
Installed Mil Thrust: 26,520lbt
Installed Max Thrust: 46,180lbt
Max Range Launch against a Foxbat AIM-120D fired from 1.4M @ FL490
Head on: 197nm (124nm flight) assuming limited to 180s on-board power
Tail chase: 48nm (120nm flight)

48 nm tail chase agaisnt a Foxbat at Mach 2.5?
Isn't that too high for AIM-120D

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 16 Aug 2019, 04:56
by sprstdlyscottsmn
Not with those launch conditions. 49,000ft and 1.4M gets uou into thin air real quick.

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 16 Aug 2019, 08:36
by garrya
sprstdlyscottsmn wrote:Not with those launch conditions. 49,000ft and 1.4M gets uou into thin air real quick.

Is it partly due to the cruising altitude of Mig-31 too? because the air is thin so it easier for AIM-120 to chase it down?

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 16 Aug 2019, 13:52
by sprstdlyscottsmn
Yes. Thin air is good for a missiles speed/range

Re: Operational Performace Comparison: Viper, Beagle, and St

Unread postPosted: 17 Aug 2019, 03:23
by garrya
sprstdlyscottsmn wrote:Yes. Thin air is good for a missiles speed/range

I put the launch condition into missile zip calculator but they do not estimate long range for any missiles, is that because they do not account for air density in their simulation?
AIM-54.PNG

AIM-120B.PNG

R-33E.PNG

R-77.PNG