LO's F-15 vs. the F-15 Streak Eagle

[upyr1]

I think we should have compared with stock F-15's not record breakers.

 

Anyway heres what i wrote about it:

http://forum.lockon.ru/showthread.php?t=22448&page=6

Do you have the climb to height record for a stock F-15 C listed?

[Kuky]

Can you try and perform this test yourself in lockon a few times more and see what height differences you get in each (for the same 56sec climb). I ask because, after all, the values you are comparing to is a RECORD meaning its only achieved once. The way in which you perform the climb matters too, along with many other things which are not modeled in lockon or any other game.

 

I bet you if the same pilot would perform the same test over and over he would get various results. I am just wondering now what differences you would get for donig the same in this sim?

[Pilotasso]

Do you have the climb to height record for a stock F-15 C listed?

 

No, unfortunatly all I have is streak eagle accounts and they are not thorough. My books are excelent but still leave me a sensation their lacking comparing to SK's -1 manual. :D

[Pilotasso]

F100-PW-100 is rated at 23,830 lbs each with afterburner, but the Streak Eagle added about 2500 lbs per engine with the use of the Vmax switch that GG mentioned.

 

F100-PW-220 delivers 23,450 lbs each with afterburner.

 

http://www.ecf.utoronto.ca/~pavacic/lomac/dragind1.jpg

http://www.ecf.utoronto.ca/~pavacic/lomac/dragind2.jpg

http://www.ecf.utoronto.ca/~pavacic/lomac/scan0183.JPG

 

-SK

 

SK could you post minimum sustained speed in level flight per altitude charts?

I think that would be enlighning as well. Believe me.

[Yo-Yo]

Just to stop speculations about F-15 "underpowered", etc.

I took the chart for maximum thrust climb (MAX, not MIL) and found that the time to get 25000 with 39000 lb initial weight for DI = 0... 40 (there is no valuable dependance on DI while this kind of klimb is performed) .

The result (please believe me :) ) was 1.1 minute + 0.5 minute to get the climb speed, i.e. 1 min 36 s.

The speed direction is 350 knots till 0.95M then 0.95M.

Though I am not SFM fan :) I managed to hold 350+-10 kts and the total time was 1min 32...33 s.

Any comment, gentlemen?

F-15 max climb.rar

[Pilotasso]

yes, my last post, minimum sustained speed in level flight, I think this is what is partialy causing the issues SK and GG are talking about, you cant fly up there without afterburner, I know for a fact that IRL you can. this is why they are saying the plane feels underpowered. I would like to see those charts. Its too bad my brothers F-16 -1 manual is not at home at the moment I would tell you that minimum speed above 30000 is closer to mach 06-07 NOT 0.8-0.9 and you are not required to lit the afterburners to maintain level flight or climb.

Naturaly if you dont speed nearly supersonic youll never be able to climb there. Wish is not IRL, you can do that without afterburner, even if much slower.

 

Yo-yo take note of the manuevers described in the pics I posted here:

http://forum.lockon.ru/showthread.php?t=22448&page=6

and then try replicate them...you cant, why? if you use the speeds and indicated there your fighter will stall. Further more your fighter will never accelerate in vertical either.

[Kuky]

I've just done a few tests myself with F-15 loaded with 28% fuel which gives it 14499kg or just over 31900lb gross weight. Started on the runway... hit SHF/BSP to show framerate and time counter... hit full afterburner... took of without flaps... keep it level to about 450/470mph (just under Mach 0.6 at sea level) and I managed to climb to just about 25000ft in 1min by doing 2.5G Immelmann (the way its noted on that first post/image).

 

I think this 1min being 4sec over 56sec of the record test is alright estimation because the bult in framerate/timer starts counting right after I start the mission and there is about 3 sec delay till engines are in full afterburner (because engines start idle) so this 1min compensates for it.

 

I think the test you have conducted is flawed :music_whistling:

[Yo-Yo]

Continue.

45000 ft climb, the same condition.

2 min 42 s (2.2+0.5 min) according the chart.

2 min 41 s in the Lockon test.

 

Gentlemen, please pay attention that the test flights (both real and Lockon) include takeoff, acceleration to the climb speed, low G maneuver and the climb itself. I want to say that the model fit the real prototype at all of these parts of flight.

 

For those who want to say that I performed many attempts to achieve these results that fit RL: I have no time to this business. There were only two attempts - one for training and one to record a track.

 

Though the discussion was very interesting the dark side of it that the BS release delayed for 1 day... :)

F-15 max climb 45000.rar

[GGTharos]

I cannot test this myself right now but,

 

Has anyone tried operating F-15C between 25000' and 35000' with -no- afterburner at a mass of 46000lbs or so? :)

 

This is supposed to be where the F-15 'lives'. :)

[Pilotasso]

Yo-YO and GG please take care of reading in the mean time, you both missed alot in my previous posts.

 

GG you are arriving to the same comclusion I had in the Su-27 thread and on this one for several pages now.

 

We are not pushing this to anyone, just giving an alert. Again we are not asking ED to change this because we understand that it wont. All we ask is you to be aware of these issues in order not to replicate the same mistakes with AFM.

[Yo-Yo]

yes, my last post, minimum sustained speed in level flight, I think this is what is partialy causing the issues SK and GG are talking about, you cant fly up there without afterburner, I know for a fact that IRL you can. this is why they are saying the plane feels underpowered. I would like to see those charts. Its too bad my brothers F-16 -1 manual is not at home at the moment I would tell you that minimum speed above 30000 is closer to mach 06-07 NOT 0.8-0.9 and you are not required to lit the afterburners to maintain level flight or climb.

Naturaly if you dont speed nearly supersonic youll never be able to climb there. Wish is not IRL, you can do that without afterburner, even if much slower.

 

Yo-yo take note of the manuevers described in the pics I posted here:

http://forum.lockon.ru/showthread.php?t=22448&page=6

and then try replicate them...you cant, why? if you use the speeds and indicated there your fighter will stall. Further more your fighter will never accelerate in vertical either.

 

Do you know the actual mass of the plane?

[Pilotasso]

In those tests no, but if in doubt use as less fuel you can as the best possible case scenario and you still wont be able to do anything of that.

It should be well T/W>1 but youll never get that even with the plane virtualy empty.

 

I dont recall the weight numbers of each model and Im not at home, though pretty much all models have T/W>1 with clean config and mission internal fuel load.

[S77th-GOYA]

45000 ft climb, the same condition.

2 min 42 s (2.2+0.5 min) according the chart.

2 min 41 s in the Lockon test.

 

 

Which chart?

[Yo-Yo]

I cannot test this myself right now but,

 

Has anyone tried operating F-15C between 25000' and 35000' with -no- afterburner at a mass of 46000lbs or so? :)

 

This is supposed to be where the F-15 'lives'. :)

 

And what's the problem? At 35000 ft at this conditions you have at least +15 m/s of Vy and ability to perform 45 degree bank turn.

The main problem is that you have only 50 knots range there you can perform these maneuvers. And it is correct. If you take a look at the flight envelope you will understand what I want to say.

[Yo-Yo]

Which chart?

 

The chart from the F-15 flight manual .

[Kuky]

Tried again...

 

28% fuel... take off no flaps and keeping level till reached 490mph (Mach 0.65) then pulled into 2.5G to 3G Immelmann. At 60sec I am past 25000ft and at 64sec I am level again at about 27000ft.

[Yo-Yo]

In those tests no, but if in doubt use as less fuel you can as the best possible case scenario and you still wont be able to do anything of that.

It should be well T/W>1 but youll never get that even with the plane virtualy empty.

 

I dont recall the weight numbers of each model and Im not at home, though pretty much all models have T/W>1 with clean config and mission internal fuel load.

 

 

I do not want to use the sources like that. If I can use F-15 Flight Manual with all parameters defined what is the reason to use something like this... some Russian authors repeated pilot's tales that Su-27 hanged on the F-15 tail very easy and though F-15 used its full AB Su-27 did not... :)

Is it a reason to retune Su-27 model? :)

[GGTharos]

It's pretty easy to stay on someone's tail w/o AB while they are in AB anyway under the right circumstances. It is nothing special - even in LO you can do it :) (Note: I refer to a turning fight)

[S77th-GOYA]

Yo-Yo, why can't the LOMAC F-15 with a 50% fuel load and clean configuration accelerate vertically?

[Yo-Yo]

Yo-Yo, why can't the LOMAC F-15 with a 50% fuel load and clean configuration accelerate vertically?

 

Velocity? Altitude?

[Yo-Yo]

It's pretty easy to stay on someone's tail w/o AB while they are in AB anyway under the right circumstances. It is nothing special - even in LO you can do it :) (Note: I refer to a turning fight)

 

Very interesting... how could you maintain ROT w/o AB in sustained turn not worse than at full AB? I want to learn this cheat!

[GGTharos]

Because even if you are slower, you are leading him in the turn :)

Like I said you need the right circumstances. But I've only done such for a short period of time so perhaps it is not possible to sustain; I will have to check :)

[S77th-GOYA]

Velocity? Altitude?

 

50 ft & 350KCAS

[Pilotasso]

Is it a reason to retune Su-27 model? :)

By all means yes, but then it wont to get to that when the AMRAAm is fixed. ;)

 

Yo-Yo, why can't the LOMAC F-15 with a 50% fuel load and clean configuration accelerate vertically?

Velocity? Altitude?

 

None that I could figure out either, not even those I posted on my books pics, because theres such a manuever described there, nor Goyas suggestion.

 

Thats the point, if even LOMAC's SFM matches the perfomance curves and you cant still accelerate in the vertical in ANY scenario or keep level flight at 30000ft without afterburner when you should, then either the engines or the drag model, or both are off. Thats why we see things that are right but others that arent.

This just reminds me, the weapons drag and drop tanks are also too high. The receeded Sparrows produce enourmous ammounts of drag in the fuselage receded hardpoints.

[TucksonSonny]

Climb rate examples:

 

 

Su-27UB.....................................1230 ft/sec

Mig-29A.....................................1000 ft/sec

Su-30MKK.................................1000 ft/sec

Su-35 (su-27M)...........................920 ft/sec

Mig-25 "Foxbat"...........................680 ft/sec

F-15C "Eagle"...............................666 ft/sec

 

 

Conclusion is obvious: Russian fighter jets climb better! ;)

 

If there was a relation between climb rate and engine performance then the Foxbat and the eagle would be best in climbing! (from this list)