Does the Su-27S climb better than the F-15C?

[wile coyote]

Hey guys, I was looking at climb rates and to my surprise the original Su27S climbs better than the F15C. I was wondering how this is possible? The Flanker supposedly has a 300 ms-1 climb rate whereas the F15C has 254 ms-1. How is the difference so great especially considering the F15 has a much better TWR and its engines perform better at higher speeds. I believe the Flanker has a better wing Loading, but can it make such a difference? Is it due to difference in payload and fuel levels? Would really appreciate if you guys could share the graphs and stats to explain it.
Thanks

 

[paralay]

Why does this surprise you?

 

[siegecrossbow]

Do we know the condition of the aircraft in question? Did it carry half fuel, full fuel? Did it carry weapons? Did it achieve the climb rate after stripping out radar/non-critical avionics and even aircraft paint in an effort to set a “record”?

 

[AGS-1787]

I was under the impression that the f-15 climbed better. The mig-29 was king in terms of climb rate. What chart is correct?

 

[sferrin]

Do we know the condition of the aircraft in question? Did it carry half fuel, full fuel? Did it carry weapons? Did it achieve the climb rate after stripping out radar/non-critical avionics and even aircraft paint in an effort to set a “record”?

The engines were tweaked to nearly 31k on the Flanker, if that tells you anything. The F-15 used normal engines. Hell, F-15s with the -129s & -229s have more power than the Streak Eagle. IIRC the Streak Eagle kept the 20km climb record.

 

[sferrin]

I was under the impression that the f-15 climbed better. The mig-29 was king in terms of climb rate. What chart is correct?

AFAIK the MiG-29 holds no FAI climb records.

 

[AGS-1787]

I’m talking about operational aircraft not the record breaking models.

 

[wile coyote]

Why does this surprise you?

Interesting. But I was under the impression that the P42 was heavily lightened and even had its thrust levels increased. I didn't think the in service Flanker could do that. Very impressive if true

 

[lolek]

The data for F-15 seems to be drastically off. Here is the relevant page from F-15B SAC (empty weight of 26 289 lbs):

Even with the twin-seater penalty, for clean aircraft the rate of climb is ca. 396 m/s (although based on the weight the value is for ca. 30% of internal fuel, and the overall thrust-weight-ratio is in this case 1.5). For the slightly heavier F-15C (empty weight of 28 476 lbs), the values look as follows:

Again, for clean aircraft with ca. 30% of fuel the value is ca. 340 m/s (TWR of 1.38). Considering the astounding TWR of the F-15, I would find it very hard for Su-27S to match it. For reference, the typical value cited for MiG-29 is 345 m/s clean, for F-16 block 15 SAC provides a value of 60 288 fpm (306 m/s) with two AIM-9J with ca. 30% of internal fuel. Later, more powerful versions of F-16 are likely to exceed this value, as based on the manuals SEP of 1200 ft/s is perfectly achievable at sea level .

 

[wile coyote]

Do we know the condition of the aircraft in question? Did it carry half fuel, full fuel? Did it carry weapons? Did it achieve the climb rate after stripping out radar/non-critical avionics and even aircraft paint in an effort to set a “record”?

I was actually hoping to find some graphs and solid data that might confirm that. My guess is for Flanker it is approx 2700 Kg fuel and 2 R27R and 2R73

 

[wile coyote]

The data for F-15 seems to be drastically off. Here is the relevant page from F-15B SAC (empty weight of 26 289 lbs):
View attachment 760463
Even with the twin-seater penalty, for clean aircraft the rate of climb is ca. 396 m/s (although based on the weight the value is for ca. 30% of internal fuel, and the overall thrust-weight-ratio is in this case 1.5). For the slightly heavier F-15C (empty weight of 28 476 lbs), the values look as follows:
View attachment 760464
Again, for clean aircraft with ca. 30% of fuel the value is ca. 340 m/s (TWR of 1.38). Considering the astounding TWR of the F-15, I would find it very hard for Su-27S to match it. For reference, the typical value cited for MiG-29 is 345 m/s clean, for F-16 block 15 SAC provides a value of 60 288 fpm (306 m/s) with two AIM-9J with ca. 30% of internal fuel. Later, more powerful versions of F-16 are likely to exceed this value, as based on the manuals SEP of 1200 ft/s is perfectly achievable at sea level .

Impressive 396 seems insane, even the Mig 29 doesn't have anywhere near that

 

[sferrin]

Interesting. But I was under the impression that the P42 was heavily lightened and even had its thrust levels increased. I didn't think the in service Flanker could do that. Very impressive if true

The P42 was stripped down and it's engines tweaked within an inch of their lives. Hell, they even replaced the radome with an aluminum one to reduce weight.

 

[Aeria Gloria]

This is from a report on Su-27 turning performance vs F-15, F-16, and Tornado. I’ll try and attach the full study but it’s likely been shared here before

Below are two charts showing excess power at 3 and 5 G, the study goes into how this means that similar G the F-15 can gain more altitude faster. The last chart shows how far behind the Su-27 is in climb speed. Though this is only an estimate. If you compare this to American data I’m sure you can get a rather full picture. I believe it is for 20 t total weight and 2x R-27 and 2x R-73.