Tips for F-15 vs Su-27 online guns only

[GGTharos]

Why do you think that the weak radar active missiles can operate in noisy environments? A P-27 at least semi-active, it works with a powerful radar of a fighter.

 

But what makes you think that makes it any better than AIM-120? Look at it this way: The power the P-27 can receive is also small (limitation of antenna size) even if the aircraft radar is powerful. But ECCM capability is sacrificed to some degree because synchronization with Su-27 radar is more difficult if it performs ECCM.

 

By contrast, with AIM-120 you have:

Launch in TWS, so ECM system is not triggered until the missile is active

Fast ECCM (at minimum frequency hopping if not digital encoding of signal) because the missile controls its own emmiter.

Additional interference from F-15C radar against the ECM hardware.

 

AIM-120 is not magical, but I don't see why you think a much older, technologically inferior missile would have any advantage over a newer one at all.

 

If you want something to compete with AMRAAM and F-15 radar, you want to look at the newer NIIP offerings combined with P-77 and its successor.

 

I know that with P-42 took off the radar. I do not know whether the ballast.

 

I hear the P-42 was specially rebuilt to take the records. If you do not balance the plane, you have a dangerous CG situation which can make the plane completely unfyable. This cannot be changed by flight computers or statically unstable designs.

The F-15A was stripped down, but engines were not tuned up to produce extra thrust (I used to think they were, but this was not the case - they may have used V-max feature of that engine).

 

Yes, the AIM-9X - the most serious opponent for the aircraft.

 

Yes, but you have to get through AIM-120/R-77's first, and those are also very serious opponents.

[GGTharos]

Those ... aren't right. I can agree with the first two, but after that, it ain't right. The F-15C will currently out-climb the Su-27S/SM any time of the day without an engine change. You can't base this comparison on TWR at SL alone. The F-15C is specifically tuned to recover a /lot/ of pressure as high altitudes and high speeds. It is a twr/speed monster in that element, and here's the important hint that'll explain it better: There's a reason why you don't see attempts at the record being made with say, an F-15E with 229's ... it would probably not quite make it, but it would demonstrate a TWR very similar to that of Streak Eagle ... in a fully operational machine.

 

The F-22 is a bit better than that in that it can be carrying more fuel plus a pull weapon complement with the same performance. No round nozzles needed - not to mention the engine tune-ups anyway.

 

Related to climb performance, here is some open source data for Thrust to Weight Ratio equal to or above 1 (100%internal fuel, Clean).

 

1.37- F-22A (with round nozzles)

1.30 - Su-35BM

1.29 - F-15K (Korean version)

1.26 - Su-27S/SM (RuAF)

1.25 - Eurofighter

1.24 - Mig-35

1.23 - Su-27SK & J-11A

1.19 - Rafale C

1.19 - Mig-29M/M2

1.19 - F-15C

1.18 - F-22A (with standard Flat nozzles)

1.16 - Su-30MKK

1.15 - F/A-18E/F

1.15 - Mig-29B (9-12)

1.14 - Su-30MKI

1.13 - Rafale M

1.13 - Mig-29 (9-13), S, SD, SE & SM

1.10 - Mig-29 BM & SMT (T/W = 1.15 during Emergency Thrust*)

1.09 - F-16E Block 60

1.09 - Mig-29K

1.09 - F-18C

1.09 - J-8III(or J-8C)

1.08 - F-35A

1.08 - F-14 B & D

1.06 - F-16C Block 52 (Block 50: T/W = 1.055)

1.05 - J-8IIm

1.04 - AV-8B+ Harrier II

1.03 - F-2A (F-2B: 1.02)

1.03 - JH-7

1.02 - F-16A Block 10

1.01 - J-8II & J-8IIb & J-8IId

1.00 - F-35B

1.00 - Harrier GR7A

[GGTharos]

Yes, you are correct. In combat situatian (ie. some specific fuel and weapon load) they are nearly equal at low altitude (So Su-27 has advantage because of turning superiority) but F-15 has much higher TWR/excess energy available at higher altitudes in the same configurations.

 

Merge with 100% fuel will probably never happen in reality.

 

With 100% of fuel in action fly only kamikaze :) F-15A/C is superior to the Su-27S/P thrust-to-weight.

[GGTharos]

BTW AAK thanks for participating in English forum. Even if we don't agree on some things relating to some planes, it's great to see that Ru/En forums are not completely separate :)

[ААК]

I think this is not the confrontation of the Su-27 and F-15. The confrontation turn and climb. Turn - this is the Su-27, F-16С, F-18, rate of climb - F-15 and MiG-29. Choose the one plane, which you like :)

 

BTW AAK thanks for participating in English forum. Even if we don't agree on some things relating to some planes, it's great to see that Ru/En forums are not completely separate

thanks :)

[ААК]

I love these discussion

You have not seen the discussion russian forums on the MiG-29 vs. Su-27.:D This is a battle to the death!:D

Edited July 12, 2011 by ААК

[GGTharos]

This was an epic discussion :D

 

You have not seen the discussion russian forums on the MiG-29 vs. Su-27.:D This is a battle to the death!:D

[RIPTIDE]

You have not seen the discussion russian forums on the MiG-29 vs. Su-27.:D This is a battle to the death!:D

CHrist... I obviously missed out on serious Google translate powered tro... em debating.

[Pilotasso]

Related to climb performance, here is some open source data for Thrust to Weight Ratio equal to or above 1 (100%internal fuel, Clean).

 

1.37- F-22A (with round nozzles)

1.30 - Su-35BM

1.29 - F-15K (Korean version)

1.26 - Su-27S/SM (RuAF)

1.25 - Eurofighter

1.24 - Mig-35

1.23 - Su-27SK & J-11A

1.19 - Rafale C

1.19 - Mig-29M/M2

1.19 - F-15C

1.18 - F-22A (with standard Flat nozzles)

1.16 - Su-30MKK

1.15 - F/A-18E/F

1.15 - Mig-29B (9-12)

1.14 - Su-30MKI

1.13 - Rafale M

1.13 - Mig-29 (9-13), S, SD, SE & SM

1.10 - Mig-29 BM & SMT (T/W = 1.15 during Emergency Thrust*)

1.09 - F-16E Block 60

1.09 - Mig-29K

1.09 - F-18C

1.09 - J-8III(or J-8C)

1.08 - F-35A

1.08 - F-14 B & D

1.06 - F-16C Block 52 (Block 50: T/W = 1.055)

1.05 - J-8IIm

1.04 - AV-8B+ Harrier II

1.03 - F-2A (F-2B: 1.02)

1.03 - JH-7

1.02 - F-16A Block 10

1.01 - J-8II & J-8IIb & J-8IId

1.00 - F-35B

1.00 - Harrier GR7A

 

where did you get that from? seems they mixed things up a little.

[Pilotasso]

Never seen an F-22 with round nozzles.

[GGTharos]

Not to mention the whole 'round nozzle' thing is funny ... incidentally, those engines now produce around 38000-39000lbf.

[mvsgas]

Never seen an F-22 with round nozzles.

 

That is one of the reason I don't trust this list, I never seen F119 with round nozzles. Also they are to generic. F-16A block 10 has so many different configuration out there, Different engine different equipment, weights. Same goes for several other aircraft.

Edit

Most people forget that those engine power numbers are based on brand new engines on a special rig at a set altitude. Never accurate in real world.

Edited July 12, 2011 by mvsgas

[GGTharos]

Installed engines always lose power, but get it back when you get that ram air effect going. The main thing that controls thrust is the intake, and some of it happens on the tail-end ... this is why you have a power curve usually peaking at M0.9 or so, and different aircraft will have different TWR at the same altitude/speed due to intake design.

 

I don't see the problem with square exhausts though, they seem to be assuming you're 'leaking' pressure which doesn't need to be true at all.

 

Dito, i think that is a theoratical assumption based on engine performances and the fact (so they they) that flat nozzles reduce power (see text below) ...but who knows.

Edited July 12, 2011 by GGTharos

[mvsgas]

Installed engines always lose power, but get it back when you get that ram air effect going. The main thing that controls thrust is the intake, and some of it happens on the tail-end ... this is why you have a power curve usually peaking at M0.9 or so, and different aircraft will have different TWR at the same altitude/speed due to intake design.

 

I don't see the problem with square exhausts though, they seem to be assuming you're 'leaking' pressure which doesn't need to be true at all.

 

:D Here we go

I do not think intake controls thrust. Many factors do. Intake helps the engine at high mach numbers. Nozzle also help regulate N1 speed. Inlet guide vanes (IGV) or Compressor inlet variable vanes (CIVV) also plays a part. Tube design, etc. Also Hours on the engine... many factors.

 

I'm looking online see if I can find the mil specs for engine testing.

[RIPTIDE]

Never seen an F-22 with round nozzles.

Might be from factory testing with round nozzles? :huh:

[Cali]

:D Here we go

I do not think intake controls thrust. Many factors do. Intake helps the engine at high mach numbers. Nozzle also help regulate N1 speed. Inlet guide vanes (IGV) or Compressor inlet variable vanes (CIVV) also plays a part. Tube design, etc. Also Hours on the engine... many factors.

 

I'm looking online see if I can find the mil specs for engine testing.

 

I know you know someone in engine shop or test cell.

[mvsgas]

I know many people from test cell and engine shop. ( here they are both the same)

[FLANKERATOR]

where did you get that from? seems they mixed things up a little.

 

Just found that on my data folder, must have saved it from somewhere a while ago. I think MATT came with the same data but anyway, I did my homework to see if it's accurate...seems not (at least not for the Su-27S/F-15C comparison):

 

First of all F-15 is lighter than the Su-27S :

12700Kg, 16000Kg respectively (Naked and empty)

 

Then F-15's P&W F100 engine delivers more Thrust than Su-27's AL-31F engine (data from Knaapo and Boeing Websites):

F-15C-----> 129000N= 29000lb= 13154kg (x2)

Su-27SK--> 122800N= 27607lb= 12500kg (x2)

 

Less weight and more engine thrust means obviously superior TWR for the F-15.

 

The only version of the Flanker with more engine thrust than the Eagle is the Su-35 (14500kg per engine).

Edited July 13, 2011 by FLANKERATOR

[GGTharos]

These figures still ain't right. Officially the -220 can deliver up to 25000lbs of thrust. You need the -229 for 29000, and the reason you don't see C's with this engine is that it simply isn't needed to counter current threats, up to and including the vast majority of flankers.

 

As discussed before, this is largely because the static thrust written down on papers is largely meaningless when it comes to a moving aircraft. It can give you an idea of things at sea level, but it doesn't tell you what happens in the rest of the envelope. Again, technically speaking the Su-27S engine delivers more thrust than that of the F-15C. Yet, the F-15C has a superior TWR.

 

This should tell you something about static vs. installed thrust (in fact, at SL, zero motion, typical installed engine thrust is 80% of rated thrust. You get it back by getting you move on). As also mentioned above, inlets can do magic to the airflow to give you more TWR at high altitude and speed than the other guy with the bigger engine.

 

Basically, the idea is like this: You can't base judgement except very very superficially. To really know what's going on you need the aircraft's PS charts.

[FLANKERATOR]

These figures still ain't right. Officially the -220 can deliver up to 25000lbs of thrust. You need the -229 for 29000, and the reason you don't see C's with this engine is that it simply isn't needed to counter current threats, up to and including the vast majority of flankers.

 

As discussed before, this is largely because the static thrust written down on papers is largely meaningless when it comes to a moving aircraft. It can give you an idea of things at sea level, but it doesn't tell you what happens in the rest of the envelope. Again, technically speaking the Su-27S engine delivers more thrust than that of the F-15C. Yet, the F-15C has a superior TWR.

 

This should tell you something about static vs. installed thrust (in fact, at SL, zero motion, typical installed engine thrust is 80% of rated thrust. You get it back by getting you move on). As also mentioned above, inlets can do magic to the airflow to give you more TWR at high altitude and speed than the other guy with the bigger engine.

 

Basically, the idea is like this: You can't base judgement except very very superficially. To really know what's going on you need the aircraft's PS charts.

 

The guys at Boeing need to be more accurate with the Technical specs, they are mentioning P&W F100 with 29000lb.

 

Anyway, makes sense because the weight difference is significant which makes the Eagle having better TWR even with slightly less powerful engines...roughly...at SL.

[Cali]

Each aircraft has a different weight. It may only be off by a little bit, but could range from a few hundred pounds.

[GGTharos]

Variable pressure control, IIRC. Can't say I have more than a slight idea on how it might work.

 

Yupp :) and ... Inlets DO magic, which makes you wonder, how they solved the supersonic-shockwave problem on the Raptor though :P ...only parts i know of are the overpressure doors....but no

glue what goes on inside.

 

Here is a nice general idea of "how stuff works"

 

http://www.concordesst.com/powerplant.html

[GGTharos]

The engine they are referring to is the F100-PW-229, which is a 29000lbf class engine.

 

F-15C's operate with the -220, which is officially rated up to 25000lbf - but, both of these engines have tunable profiles.

 

The -220 is basically a significant upgrade to the -100. From the competing side you have the GE engines with similar thrust, and the newest engine is 32000lbf - for that generation, IIRC, and it used in F-16's and one of the export strike eagles.

 

The guys at Boeing need to be more accurate with the Technical specs, they are mentioning P&W F100 with 29000lb.

 

Anyway, makes sense because the weight difference is significant which makes the Eagle having better TWR even with slightly less powerful engines...roughly...at SL.

[mvsgas]

Most website refer to the F100 are talking about the entire family PW engines (100,200,220 and 229) There are all consider F100. Same way all version of the F110 are refer to as F110. All have different power settings and different version as well. They do not have Tunable profiles. You can adjust them depending on the fuel but not tunable profile. You have a switch that allow for more power, but after use engine needs complete overhaul.

 

The F-22 intake is not a straight tube like F-4, F-15, B-1B, etc. The tube is designed to help with shock wave. It has bypass doors to help with overpressure.

 

I think some units with F-15C do have -229

 

Just my two cents

 

Edit

You are right, F-15C do not use -229

Edited July 13, 2011 by mvsgas

[ААК]

The only version of the Flanker with more engine thrust than the Eagle is the Su-35 (14500kg per engine).

At some Su-27SM installed engines AL-31FM1 with traction 13,3-13,5 tonn.

In previous reports they write that F100-PW-229 is not on the F-15C, then F100-PW-229 is installed on heavy F-15E.