Forum: General F-22A Raptor forum

Quote:

I'm interested in the claim that the F-15 and F-22 have similar top speeds even though the F-22 "can accelerate faster" (heard from pilots and various outlets). Unless the F-22 is a step backwards in aerodynamics, F=ma (with a bigger a) means more thrust and a higher top speed.

From all the paint-peeled F-22 noses and aerospace's continual struggle for robust turbines, I'd throw my hat in with the folks who say it's an airframe/material limitation.

Speed isn't everything. There was a time when speed was everything, and this time effectively ended when missiles able to reach M 4+ (or M 7+, like the SA-10/SA-12 and the likes) entred operation. Remember that there aren't free lunches: to reach such a high speed as M 2.5+ for more than a few seconds per mission, you must sacrifice other things, like using special materials (titanium or the like), complex (cough*expensive*cough) intakes, wings unusable for anything other than high altitude straight flight, etc.. Concorde, Blackbird, "Foxbat"/"Foxhound", to name the most famous ones, have all these features. For today's CONOPS, the most important features are supercruise, superagility, sensor fusion, and stealth. As mentioned before, acceleration is better than top speed, so is supercruise. More important than reaching M 3.5 for 5 minutes is keeping M 1.75 for 30 minutes. F-22 can do that while carrying a full internal payload. No other aircraft can do that. I doubt EF can supercruise, and if it does, is on clean configuration. Very useful for escaping but not so for fighting. LMAO

Anyway, I bet my grandchildren will get the REAL info, but for any of us not involved with the program, I highly doubt so.

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A lot of planes claim supercruise but it seems that the engine is the limiting factor. Check the turbine inlet temp for the F119 and that for the Rafale and EF engines. How realistic is a supercruise with those engines and how long do they last?

shingen wrote:

A lot of planes claim supercruise but it seems that the engine is the limiting factor.

One thing about supercruise is engine performance, another one is the aerodynamic of the fighter in the transonic and supersonic regime of speeds.

Regards

Rapec wrote:

shingen wrote:

A lot of planes claim supercruise but it seems that the engine is the limiting factor.

One thing about supercruise is engine performance, another one is the aerodynamic of the fighter in the transonic and supersonic regime of speeds.

Agreed, Supercruise = Specific excess thrust minus airframe drag.

The F100 and F110 would push the Viper above MACH 1 when 'clean', but add two empty 370 drop tanks, and that possibility is gone.

The Raptor is a large jet, but completely 'clean' in combat trim, coupled with the high specific thrust of the F119, and you're haulin' @$$ into action.

TEG

shingen wrote:

cola wrote:

"OT, F22 better make M2 on dry thrust, since one of its F119s produces roughly the same thrust (in dry power) as a pair of EF's EJ200s at 40k ft, which makes ~M1.5."

That's it right there.

I see... (thought you were bothered with previous parts)

Anyway, no trolling here, either.
As reported (and demonstrated), EF in QRA load does M1.3 (~M1.5 clean) in dry and so F22 with roughly double installed thrust at 40k ft, BETTER does M2.
Why?
Because, all I've been reading on this (and other) forums, is how F22 is an aerodynamic marvel.
To be honest, it probably is for LO plane, but that has nothing to do with absolute meaning of the word and it's Cd (drag coeff) is probably pretty funny compared to thoroughbred high-speed interceptors.
To be precise, F22's aerodynamics (as any plane's) is a compromise between requirements and possibilities (material related, mainly).

One example would be F22's wing leading edge's sweep.
YF22 had M1.5 SC KPP requirement and once F119 came online (it's power performance became known), LM's designers could decrease wing sweep, to gain some lift performance, while still fulfilling M1.5 KPP.

So, no trolling here...it's actually the other way around and if one would go correcting every bit of ridiculous posting here, that would be a full time job.
Don't mind me popping in, here and there and better examine what someone says, before proceeding with accusations.

The problem with your current troll .... er argument Sodaboy is that your M 1.5 figure for Typhoon is not really valid. The Germans have it as "up to 1.2" and AFM has it as M 1.1. Your 1.5 figure is derived from the Austrian Luftwaffe number. That number came from the "infamous" Singapore evaluation where a clean Eurofighter with non production engines flew in high cold air to demonstrate that it could reach M 1.5. The reality is that the Eurofighter can do no more than most other aircraft in production configuration and combat trim. Maybe M 1.1 - 1.2 which is in no way tactically useful. The reason I point this out is that this is like most of your arguments in that you use suspect, faulty, or taken out of context data to support your arguments. There is absolutely no KPP of M1.5 for Eurofighter and I challenge you to produce proof that there is. Frankly you need to get your fact straight before you take the mantle of fact checker in chief.

There was no report about M 1.5 from Singapore and the aircraft evaluated there were stock block 1 twin seaters, not prototypes with fancy stuff etc. USAF states M 1.5 for the F-22 should we ignore now all other figures above that?

cola wrote:

To be honest, it probably is for LO plane, but that has nothing to do with absolute meaning of the word and it's Cd (drag coeff) is probably pretty funny compared to thoroughbred high-speed interceptors.

I suppose that in those deliberation about Cd of thoroughbred high-speed interceptors and F-22 you may have forgotten about one, small but funny issue concerning classical interceptors - external weapons load.

Regards

Scorpion82 wrote:

There was no report about M 1.5 from Singapore and the aircraft evaluated there were stock block 1 twin seaters, not prototypes with fancy stuff etc. USAF states M 1.5 for the F-22 should we ignore now all other figures above that?

Actually the air force states

Quote:

Mach 2 class with supercruise capability

http://www.af.mil/information/factsheet ... asp?id=199

Other reputable, reliable sources quote the numbers in excess of M 1.5.

The engines in the Typhoon in Singapore where the 1.5 report came from where "ringers" they where not typical production units.

Please don't try to continue to derail the thread.

cola wrote:

I see... (thought you were bothered with previous parts)

Anyway, no trolling here, either.
As reported (and demonstrated), EF in QRA load does M1.3 (~M1.5 clean) in dry and so F22 with roughly double installed thrust at 40k ft, BETTER does M2.
Why?
Because, all I've been reading on this (and other) forums, is how F22 is an aerodynamic marvel.
To be honest, it probably is for LO plane, but that has nothing to do with absolute meaning of the word and it's Cd (drag coeff) is probably pretty funny compared to thoroughbred high-speed interceptors.
To be precise, F22's aerodynamics (as any plane's) is a compromise between requirements and possibilities (material related, mainly).

One example would be F22's wing leading edge's sweep.
YF22 had M1.5 SC KPP requirement and once F119 came online (it's power performance became known), LM's designers could decrease wing sweep, to gain some lift performance, while still fulfilling M1.5 KPP.

So, no trolling here...it's actually the other way around and if one would go correcting every bit of ridiculous posting here, that would be a full time job.
Don't mind me popping in, here and there and better examine what someone says, before proceeding with accusations.

Is this where you come in claiming the F-15is more aerodynamic than the F-22 as you've claimed elsewhere in the past. How anyone in their right mind could come to such a laughable conclusion is beyond me. By all accounts the F-22 is an aerodynamic marval especially considering it combines very low obseravbility built in, tough luck if you cannot except that but you'll only look daft trying to say otherwise.

Thumper3181 wrote:

http://www.af.mil/information/factsheet ... asp?id=199

Other reputable, reliable sources quote the numbers in excess of M 1.5.

You obviously missed my point, the point is that the numbers on the official websites aren't necessarily the ultimate once. You often have KPPs and that's it.

Quote:

The engines in the Typhoon in Singapore where the 1.5 report came from where "ringers" they where not typical production units.

Any reliable source for it?

Quote:

Please don't try to continue to derail the thread.

Me derailing the thread? I made a single post to reply to a statement of yours which is incorrect according my info. So how I'm derailing this thread and you not?

Here's the tactic: Post a snarky (sometimes) post with a little bit of data attacking F-22 or F-35. Compare it to another plane that measures up favorably in one area. Example: "Yeah, F-22 can do things but it costs a lot and only carries one person. An A380 can carry 800 people. (Insert snark about stupid americans or high price or usefulness of VLO here)" Does it matter? Which can perform the mission of OCA in the face of qulaity SAMs more effectively? Also, do any A380's actually carry 800 people? No, but it derails the thread and that's the objective. The fact is the F-22 is designed for a far more strenuous mission than the Typhoon, the F-22 is the best OCA fighter in the world, and some people don't like that.

Oh BTW, I know all the facts about everything but wouldn't deign to post them here.

I that's not trolling I don't know what is.

At whom were these posts aimed shingen?

Not you. I appreciate the respect you show to people who disagree with you.

Forum: General F-22A Raptor forum

F-22 - True Supercruise speed?