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Lockheed Martin F-22A Raptor

LowObservable

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I say old man, would you mind directing me to the first-stage compressor? Left, up down and right again? Righty-ho, thanks!
 

F-14D

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A recent issue of Aviation Week was discussing the potential for a limited increase in orders for the F-22 (USAF has not given up) until the F-35 arrives. In it noted, without elaboration, that the Raptor had missed several key parameters. Now I familiar with how it's turned out that the F-22 needs noticeably more maintenance than expected for this stage in its career, is anyone else aware specifically of what AvWeek is talking about?
 

Abraham Gubler

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Fuel fraction and radius are well down from the ATF RFP. Also the F-22's networking ability would be suspect since it doesn't have Link 16.
 

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Abraham Gubler,

Why did they reduce the design's fuel fraction? Also, what is Link 16?


KJ Lesnick
 

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http://en.wikipedia.org/wiki/Link_16
 

sferrin

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KJ_Lesnick said:
Abraham Gubler,

Why did they reduce the design's fuel fraction? Also, what is Link 16?


KJ Lesnick
Just a guess but the supercruise speed exceeds the requirement so maybe they traded range for performance (altitude, speed, manueverability, etc.)
 

Abraham Gubler

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sferrin said:
Just a guess but the supercruise speed exceeds the requirement so maybe they traded range for performance (altitude, speed, manueverability, etc.)
Sort of but not to exceed but to just manage to make. The maximum supercruise is M1.7 which is sort of exceeding the specification (M1.6) but not that important as the operational supercruise speed remains M1.5. The reason 25% of the RFP requirement for fuel (and subsequently a lot of range) was dropped was to reduce aircraft weight so as to meet the RFP performance spec.
 

KJ_Lesnick

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I did a search and found out what Link 16 was. From what it seems it's a system which involves sharing battlefield data so everybody on the same side has the same battlefield picture.


KJ Lesnick
 

sferrin

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Abraham Gubler said:
sferrin said:
Just a guess but the supercruise speed exceeds the requirement so maybe they traded range for performance (altitude, speed, manueverability, etc.)
Sort of but not to exceed but to just manage to make. The maximum supercruise is M1.7 which is sort of exceeding the specification (M1.6) but not that important as the operational supercruise speed remains M1.5. The reason 25% of the RFP requirement for fuel (and subsequently a lot of range) was dropped was to reduce aircraft weight so as to meet the RFP performance spec.
A general mentioned supercruising at Mach 1.72. Since generals aren't typically in the habit of publicly announcing the capability of aircraft it stands to reason that it's probably better than that. As for needing to drop weight to meet a performance spec. it's been published numerous times that both the YF-22 and YF-23 met all requirements. What sources indicate the YF-22 failed to meet the requirements?
 

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As far back as 1994, when the F-22 was getting overweight (on part of the AF request which wanted additional A/G capability) the USAF I think, decided to relax some of the performance requirements. Specifically those were maneuver requirements (sustained turn rate at altitude) so the F-22 can meet them.

I remember a time when its empty weight was quoted as 14,5 tones and now its somewhat over 19 tones. That has to mess up a few things even if the plane can still pull 9Gs.

More recently, the F-22 has yet to demonstrate it meets the maintenance requirements. Reports suggests its readiness level is improving as the crews get more experience with it but its still not there yet.

Another thing I read a while back was concerns of limited supercruise. Because of the high operating temperatures of the two engines and in particular their proximity, the rear section was experiencing unexpected wear levels, forcing the planes to cut down on the time it can spend in supercruise.

The thing is that while the Raptor may have fallen short of some of the few requirements it was supposed to meet on paper, it more than compensated with other capabilities that came up expectedly and are still classified.
 

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Yes, but we still can not explain why some pilot fly the F-22 over 1.72 (some claimed 1.81) without using afterburner.
The Climb rate not be unveiled yet.
 

sferrin

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Several years ago a couple F-22 pilots made comments that were quickly removed and debated hotly for a week or two. Not anything Dozer said. The first time the F-22 did a performance for the general public at Oshkosh (Wisconsin) one of the pilots interviewed made the comment "we could have made the trip in a half-hour or so if we'd wanted". It's 800 miles from Langley to Oshkosh. Even in afterburner that would be an accomplishment. Sure, there are several bombers and the Blackbird and Mig-31 that could do it but they're designed for that kind of thing. One other pilot made the comment about "cruising at Mach 2 and 60,000 feet".
 

lantinian

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The F119-PW-100 engines have very low bypass ration (0,2) which makes it similar to a turbojet engine. In a sense, it may be expected for the F-22 to come close to the performance of a fighter with similar trust to weight ration and turbojet engines on full afterburner .

The engines type is very important since turbojets retain their trust better with supersonic speeds, while the turbofan efficiency drops sharply above Mach 1

As is happens the F/A-18C has also two turbojet like engines and fixed air intakes. The Hornet was also optimized for similar max speeds as the Raptor and it has a similar trust to weight ration, provided it is on afterburner and the F-22 is on max military power.

The F/A-18C max speed is quoted as Mach 1.8 in clean state at 40,000 feet. I just cannot believe the F-22 will be able to do significantly better than that, given the fact that is has a lot more internal volume, even if its wings have higher sweep.

Now, I remember a document that was meant for the US Congress stating the F-22 super-cruise speed to be 15% above requirements. Given a requirement of Mach 1.5, this makes for max super-cruise speed of Mach 1,75 which is in line with the statements of a certain USAF general.

I also think 100% military power is not considered super-cruise setting. Its more like 90-95%. So it is highly likely that the F-22 can get to Mach 1,82 or even Mach 2 without afterburner under optimum condition (minimal fuel and weapons) but this is by no means a sustained speed and true super-cruise implies.

Further, I do believe the F-22 airframe itself was designed to be most efficient at Mach 1,5 even if the engines could push it to a greater speed.
 

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Some tests before the first Raptor flew with a fuel rig test model with four fuel tanks. This rig was designed to test the full furl system up to 60 AoA. As far as I remember, something was discovered that made it impossible for the F-22 to cary 4 fuel tanks as advertised. Some problem with the wings, I guess.

I remember that each time I see a Raptor with fuel tanks, but each time it has only two.

Anyone seen a picture of the F-22 with 4 fuel tanks, which it was designed to carry?

There are many diagrams on the web with an F-22 with 4 fuel tanks and 8 missiles under the wings in ferry configuration with their tails removed. I wonder, when will the USAF try that one.
 

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F-22 flight envelope sans AB.
I am pretty convinced, this diagram is not accurate for neither aircraft. I have read in many placed of the F-22 being the fastest aircraft at sea level, capable of Mach 1,25. The diagram shows it barely doing Mach 1,1. Even the F-15E can do better.

As for the F-35.... Once they start testing of the lighter versions with the more powerful engines, I think we will up for a surprise.
 

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Well, you always have certain, uhh, odd ones here and there who make claims about the F-22 being a Mach 3+ aircraft.

And strangely enough, their claims are always uncited. Hmmmmmm.....
 

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lantinian said:
F-22 flight envelope sans AB.
I am pretty convinced, this diagram is not accurate for neither aircraft. I have read in many placed of the F-22 being the fastest aircraft at sea level, capable of Mach 1,25. The diagram shows it barely doing Mach 1,1. Even the F-15E can do better.

As for the F-35.... Once they start testing of the lighter versions with the more powerful engines, I think we will up for a surprise.
I'm sure that the F-22 is faster than shown, when in afterburner. I'm somewhat surprised that it is that fast without afterburner, even though at something like "combat weight", which is with roughly 50% fuel expended or mid-mission...

As for the F-35 getting lighter, I'm not at all sure about that.
 

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lantinian said:
F-22 flight envelope sans AB.
I am pretty convinced, this diagram is not accurate for neither aircraft. I have read in many placed of the F-22 being the fastest aircraft at sea level, capable of Mach 1,25. The diagram shows it barely doing Mach 1,1. Even the F-15E can do better.
Please note that the flight envelope says "military power" this means maximum engine thrust without reheat, ie no afterburner. Both aircraft (F-22 and F-35) would have much larger and faster envelopes with the greater thrust available by using reheat.
 

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Tailspin Turtle said:
As for the F-35 getting lighter, I'm not at all sure about that.
Why not? you only have to ask the marketing people and the lobbyists. The people who promised the F-22 for the same weight as the F-15, and sold the F-35 for $35M. Don't ask those gloomy engineers. Those guys have no imagination and believe in the laws of physics.
 

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Here's the original Oshkosh quote. Looks like it was Dozer who said it.

"Raptor Rocks
Airspacemag Aug-Sept 2006

Shower was joined at Oshkosh that day by Col. Thomas Bergeson, who entertained us with high-speed, excruciatingly loud passes in another Raptor while Shower flew off to collect his airplane for its next stunt. One of them he calls "the helicopter." The airplane is falling straight down, but rotating in a spin. This is one of Shower’s favorites—the guy must have a stomach made of titanium.

The jet can sustain over 30 degrees per second of yaw, he marvels. "Thirty degrees per second in an F-15? The beeper’s going off and I’m in an uncontrollable spin. But in an F-22, it’s totally controllable, and you’re just going ‘dit da dit da duh,’ " he hums. "And I’ll push the pedal the other way, and it will just stop and go 30 degrees in the opposite direction." Shower laughs in gleeful disbelief that an airplane will allow him to have this much fun.....

He’s seen demos and videos of performances by the Russian MiG 29 and Sukhoi Su 35, and admits that their maneuverability is probably on a par with the F-22. "I can do everything they can do and vice versa," he says. "We can all do some pretty neat stuff. But I love this part of it: That’s all they have. They don’t have the stealth , they don’t have the supercruise, they don’t have the integrated sensors, the avionics. We have an aircraft that does everything a fighter pilot has ever wanted to do. It has it all—you can tell by the price tag," he says, (about $137 million per copy, or $338 million if you count in all the Air Force's research costs).

For their performance, which started at 2:40 p.m., Shower and Bergeson took off from Langley, 800 miles away, at about 1:25. "We were going slow," Shower says. "We were only doing about .9 Mach. Over the continental United States, there’s only a couple of places we’re allowed to go supersonic so we don’t scare everybody. But we did the math and figured we could be there if we supercruised in about 25 or 30 minutes. "
 

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AeroFranz said:
Tailspin Turtle said:
As for the F-35 getting lighter, I'm not at all sure about that.
Why not? you only have to ask the marketing people and the lobbyists. The people who promised the F-22 for the same weight as the F-15, and sold the F-35 for $35M. Don't ask those gloomy engineers. Those guys have no imagination and believe in the laws of physics.
Let's see, be realistic, lose the competition, and get laid off? Or be optimistic, win it, keep your job, have a chance of meeting your numbers, and probably not be punished for not meeting them? Oh, and the competitions are only held once a decade or so, which means that the loser will probably go out of business or be bought by another company and their engineers will likely have to find a job at the winning company. Talk about gloomy. What to do, what to do? I think you can guess what we do. Even the engineers. Or at least enough of them to write the proposal and discuss it with the government's engineers.
 

sferrin

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Tailspin Turtle said:
AeroFranz said:
Tailspin Turtle said:
As for the F-35 getting lighter, I'm not at all sure about that.
Why not? you only have to ask the marketing people and the lobbyists. The people who promised the F-22 for the same weight as the F-15, and sold the F-35 for $35M. Don't ask those gloomy engineers. Those guys have no imagination and believe in the laws of physics.
Let's see, be realistic, lose the competition, and get laid off? Or be optimistic, win it, keep your job, have a chance of meeting your numbers, and probably not be punished for not meeting them? Oh, and the competitions are only held once a decade or so, which means that the loser will probably go out of business or be bought by another company and their engineers will likely have to find a job at the winning company. Talk about gloomy. What to do, what to do? I think you can guess what we do. Even the engineers. Or at least enough of them to write the proposal and discuss it with the government's engineers.

Cowardice drove honesty out the window back in the late 80's. Since then the incapacitating terror of risk/failure has killed more progress than the most incompetent politician ever dreamed of.
 

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sferrin said:
Tailspin Turtle said:
AeroFranz said:
Tailspin Turtle said:
As for the F-35 getting lighter, I'm not at all sure about that.
Why not? you only have to ask the marketing people and the lobbyists. The people who promised the F-22 for the same weight as the F-15, and sold the F-35 for $35M. Don't ask those gloomy engineers. Those guys have no imagination and believe in the laws of physics.
Let's see, be realistic, lose the competition, and get laid off? Or be optimistic, win it, keep your job, have a chance of meeting your numbers, and probably not be punished for not meeting them? Oh, and the competitions are only held once a decade or so, which means that the loser will probably go out of business or be bought by another company and their engineers will likely have to find a job at the winning company. Talk about gloomy. What to do, what to do? I think you can guess what we do. Even the engineers. Or at least enough of them to write the proposal and discuss it with the government's engineers.

Cowardice drove honesty out the window back in the late 80's. Since then the incapacitating terror of risk/failure has killed more progress than the most incompetent politician ever dreamed of.
Hmmm... That makes the brilliant and high-risk solution to vertical performance successfully accomplished with the turbine shaft-driven, counter-rotating lift fan in the X-35 even more exceptional. Honest (since it turned out to be doable, and that wasn't a sure thing by a long shot) and brave. Your examples of cowardice and progress-killing incapacitating terror are?
 

AeroFranz

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Tailspin, you have some good points and I guess I am venting the frustration shared by engineers (BTW, i am one, working in the aerospace industry and obviously passionate about it) and aviation anthusiasts who see the future of their profession and love going down the tubes - the fact remains that the current state of affairs is unsustainable.
I just don't think it has to be this way, this monstruous, deeply-flawed acquisition process that feeds on itself. I look to the future and it's pretty bleek. We go from thousands of B-52s to a few hundred B-1s to 21 (now 20) B-2s. Parallel that to fighters, with 750+ F-15s, 183 F-22, and then...? Are we seriously going to afford some 60 fighters total? ???

To go back somewhat to the original topic of this thread, the F-22 and its follow up are going to be the most stellar performers in the sky arena, but if there are only a few dozens around they will not be relevant. Why isn't affordability in numbers included as one of the system key performance parameters? There is only so much that quality can address over quantity.
 

sferrin

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Tailspin Turtle said:
sferrin said:
Tailspin Turtle said:
AeroFranz said:
Tailspin Turtle said:
As for the F-35 getting lighter, I'm not at all sure about that.
Why not? you only have to ask the marketing people and the lobbyists. The people who promised the F-22 for the same weight as the F-15, and sold the F-35 for $35M. Don't ask those gloomy engineers. Those guys have no imagination and believe in the laws of physics.
Let's see, be realistic, lose the competition, and get laid off? Or be optimistic, win it, keep your job, have a chance of meeting your numbers, and probably not be punished for not meeting them? Oh, and the competitions are only held once a decade or so, which means that the loser will probably go out of business or be bought by another company and their engineers will likely have to find a job at the winning company. Talk about gloomy. What to do, what to do? I think you can guess what we do. Even the engineers. Or at least enough of them to write the proposal and discuss it with the government's engineers.

Cowardice drove honesty out the window back in the late 80's. Since then the incapacitating terror of risk/failure has killed more progress than the most incompetent politician ever dreamed of.
Hmmm... That makes the brilliant and high-risk solution to vertical performance successfully accomplished with the turbine shaft-driven, counter-rotating lift fan in the X-35 even more exceptional. Honest (since it turned out to be doable, and that wasn't a sure thing by a long shot) and brave. Your examples of cowardice and progress-killing incapacitating terror are?
NASA's latest ideas for going to the moon could be considered "exhibit A".
 

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AeroFranz said:
I just don't think it has to be this way, this monstruous, deeply-flawed acquisition process that feeds on itself. I look to the future and it's pretty bleek. We go from thousands of B-52s to a few hundred B-1s to 21 (now 20) B-2s. Parallel that to fighters, with 750+ F-15s, 183 F-22, and then...? Are we seriously going to afford some 60 fighters total? ???
Simple numbers of airframes is not an indication of the industry's health. Company profits are strong, employee numbers are strong, turnover per employee is strong. While the number of airframes are done the amount of work for each is up and while the number of aircraft designs is down the amount of work per aircraft is up. And what about all those UAV platforms being designed today? Too many!

That being said I am no apologist for the procurement system. Project management by Sir Antony Jay just doesn't work. Even the concepts phase is flawed. Both F-22 and F-35 should have been scrapped in the late 1990s when it was clear technology had made them far less capable than the alternative of FB-23 and X-45.

And in the 1950s there may have been 20 bomber aircraft designed in the West and in the 1990s only 1. But those 20 1950s aircraft had between them 10,000 lines of software code whereas the single 1990s bomber had 10,000,0000... So I guess get into software engineering not aerospace :eek:
 

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AeroFranz said:
Tailspin, you have some good points and I guess I am venting the frustration shared by engineers (BTW, i am one, working in the aerospace industry and obviously passionate about it) and aviation anthusiasts who see the future of their profession and love going down the tubes - the fact remains that the current state of affairs is unsustainable.
I just don't think it has to be this way, this monstruous, deeply-flawed acquisition process that feeds on itself. I look to the future and it's pretty bleek. We go from thousands of B-52s to a few hundred B-1s to 21 (now 20) B-2s. Parallel that to fighters, with 750+ F-15s, 183 F-22, and then...? Are we seriously going to afford some 60 fighters total? ???

To go back somewhat to the original topic of this thread, the F-22 and its follow up are going to be the most stellar performers in the sky arena, but if there are only a few dozens around they will not be relevant. Why isn't affordability in numbers included as one of the system key performance parameters? There is only so much that quality can address over quantity.
Not sure where you got your numbers but there certainly were never thousands of B-52s or hundreds of B-1s.
 

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Affordable numbers as a system parameter is a very interesting issue. The F 22 purchased in the originally envisaged numbers (750) probably didnt have to face todays quandry that like the Me 262 its may be the best but be outnumbered and in such weak numbers that as a system it may not be effective. What this really comes down to is am embedded (or just corrupt as GAO implies carefully) military procurement process by which I mean a failing new weapon system at the development / procurement stage can be kept alive through a combination of big money from the manufacturers at the lobbying level to keep a system alive and a healthy amount of weak technical oversite.

Not so long ago the A12 was cancelled for failing in development. Recently we had the Comanche. But alot of manufacturers have learned that if you provide no alternatives, bs the development cost, reporting and lets face it, throw alot of money around Congress, you can keep a system alive. Its a real shame GAO doesnt have more power for while innovation often comes at the price of setbacks, F 35s that were sold as 35 mil and F 15 weight F 22s should have been cancelled or the manufacturers penalised a long time ago. This is realy a problem America has at a deeper level and you see it not just in aerospace where many fine forumers here work but in the financial sector where similarily multinational interests have deliberately weakened / discouraged governmental oversight.
 

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ubiquitous08 said:
Affordable numbers as a system parameter is a very interesting issue. The F 22 purchased in the originally envisaged numbers (750) probably didnt have to face todays quandry that like the Me 262 its may be the best but be outnumbered and in such weak numbers that as a system it may not be effective. What this really comes down to is am embedded (or just corrupt as GAO implies carefully) military procurement process by which I mean a failing new weapon system at the development / procurement stage can be kept alive through a combination of big money from the manufacturers at the lobbying level to keep a system alive and a healthy amount of weak technical oversite.

Not so long ago the A12 was cancelled for failing in development. Recently we had the Comanche. But alot of manufacturers have learned that if you provide no alternatives, bs the development cost, reporting and lets face it, throw alot of money around Congress, you can keep a system alive. Its a real shame GAO doesnt have more power for while innovation often comes at the price of setbacks, F 35s that were sold as 35 mil and F 15 weight F 22s should have been cancelled or the manufacturers penalised a long time ago. This is realy a problem America has at a deeper level and you see it not just in aerospace where many fine forumers here work but in the financial sector where similarily multinational interests have deliberately weakened / discouraged governmental oversight.
Taken straight from the headlines of newspapers and just as wrong.

The persistent problem with developing new weapons since 1989 has been money. "Less money this year but we still want it," has equaled all the problems. Also the assumption that you can develop a new piece of technology without any risk.

No one is "lying" to the extent that you make out. The problem is the answers given are very complex. For example F-35 per unit cost. There are several costs because there are more things than just a flyaway aircraft from a lot purchased and the use of base year dollars to accurately benchmark changes in cost without being caught up with inflation and even deflation.

People aren't being lied too about defence acquisitions they are just too stupid and/or lazy to bother working out what it all means.
 

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Well I guess the GAO , and Mr Gates are simply uninformed, what with both have access to classified data like performance specifications. Adding to that in the commercial world where many of us work, we scratch our heads at the comments cost escalations are somehow the result of insuffient development money. and a fasilure to recognise complexity. Call me a fool but when you sell a certain specification for a certain price, your expected to deliver not shrug your shoulders and ask for more money. Is 40 billion U.S too little to field 750 Raptors as the projects cost was originally capped at? Is the JSF advertised to cost roughly 50- 70 million and now escalating an unreasonable concearn? Some of our greatest weapons systems have come from those brave enough to question cost escalation and do better ( F 16) . Back in the day we had something called fixed price contract; it cut through the BS. We also had real oversight. Suggesting that concearn over costs isn't in part due to a corrupt system (Boeing tanker deal) is naive. It rests with the notion that the private sector will right all wrongs.

A final thought: Boeing and Airbus both delivered products late (787) (Airbus A 380) and both have paid penalties for performance (in service date delays) pitfalls. Why hasnt that happened in military procurement? Look at the tanker deal. Real honest right? Finally Gates, our new defence chief must be real uninformed to want to cut overpriced underperforming systems ( F 22 avionics specifications downgrade anyone?). What would he know?
 

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sferrin said:
Just a guess but the supercruise speed exceeds the requirement so maybe they traded range for performance (altitude, speed, manueverability, etc.)
Duh? What's the point in supercruise if your range is reduced? (this is retorical, not actually a question)

As to rediculous procurement overspends, performance shortfalls and missed delivery dates, we all know this would be called coruption or at least incompetence in the real comercical world. If you want a prime example just look at the the Nimrod MRA4. An ungrade to an existing aircraft of 1950s design started in 1992 and still nowhere near completion. It's not just the American system that's in trouble.

[edited by site admin to remove personal attack]
 

sferrin

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Woody said:
sferrin said:
Just a guess but the supercruise speed exceeds the requirement so maybe they traded range for performance (altitude, speed, manueverability, etc.)
Duh? What's the point in supercruise if your range is reduced? (this is retorical, not actually a question)
Both the YF-22 and YF-23 are claimed to have met all performance requirements. The F-22A has something like 6000lb - 7000lbs less fuel than the YF-22 and is faster. If they didn't do it because they wanted more speed (than spelled out in the met requirement) then what is your explanation for the change? Of course it could be something more complicated like they changed several large structural memebers from composite to Ti so they had to lose weight somewhere, they chose fuel, which meant not only did they lose the weight of the fuel but now they don't need the space so the aiircraft gets slimmer in some areas (reducing drag) and increasing speed. Who knows? The fact of the matter is you still don't see it trucking around fuel tanks on a regular basis like all the -teens.
 

ubiquitous08

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Spey I remember really took issue with the F 22 being too overweight to have a useful ability to supercruise; I think over half an hour was called for. Was Spey wrong or is the F 22 a bit short legged? Iam not sure Spey factors in the very high operating altitude of the F 22 (50-70,000 ft I believe) that may make the Raptor quite long legged in a supercruise regime at that altitude. A final thought. How good can the F22's VHF stealth be? I ask this because the rear seems a little on the short side (panel lengths to match 2m wavelengths). Perhaps I'm missing something? i say this because the very polarising Carlo Kopp alleges the f 35 is very poor in this arena yet he claims the F 22 has wideband stealth.

http://www.ausairpower.net/APA-Rus-Low-Band-Radars.html

http://www.ausairpower.net/APA-Nebo-SVU-Analysis.html in particular for Raleigh scattering.
 

sferrin

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Sprey is fairly biased when it comes to large fighters of any sort. He and the "fighter Mafia" went to great lengths to discredit the F-15 and both him and Ricionni have contiued to carry the torch with the F-22.
 

Abraham Gubler

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sferrin said:
Sprey is fairly biased when it comes to large fighters of any sort. He and the "fighter Mafia" went to great lengths to discredit the F-15 and both him and Ricionni have contiued to carry the torch with the F-22.
I think you're being unfair to Ricionni about the F-22, he wrote the ATF specification so he's hardly an anti F-22 person. Probably just very upset that the aircraft didn't emerge as the Fast Transient aircraft that Boyd had envisaged.

The criticism about the F-22A's weights is fair. The YF-22 was bid as carrying 24,000 lbs of fuel and the F-22A emerged with 18,000 lbs (a 1/4 cut) which resulted in the supercruise endurance reduced to about 10 minutes in a 500 NM radius mission. Wether this performance is worth the cost of the F-22A with all its reduction in C4ISR and weapons load capability compared to the F-35A is the item of debate that the F-22A and all its supporters have thoroughly lost in the past years. Not that you would realise it reading much of the public commentary which is ill informed, biased and generally as wrong as its always been.
 

sferrin

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Abraham Gubler said:
I think you're being unfair to Ricionni about the F-22, he wrote the ATF specification so he's hardly an anti F-22 person.
I'd be interested in reading your source of that information.
 

overscan

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From James Stevenson post on skunk-works-digest

The seminal work on supercruise was done by Col. Everest Riccioni USAF
Ret. at the Northrop Corporation during the early years of the ATF
competition. He determined that fuel fraction was a critical factor in
obtaining range for a supercrusing aircraft. At the time of the ATF
competition, the range goal for the ATF was to cruise sub-sonically for
100 miles, then in 400 miles in supercruise, back out in supercruise,
and home 100 miles subsonically.

The F-22 has breached the Riccioni ideal of 0.38 as well as the minimum
acceptable fuel fraction of 0.35 due to increasing weight. Indeed, the
Air Force admits to a fuel fraction of 0.29, a figure that is bettered
by other aircraft including the F-15C, the aircraft the F-22 was
designed to replace. The F-22 does not have the fuel fraction of, for
that matter, the F8H a Navy jet that first flew in the mid-1950s.
Riccioni estimates that the F-22 at its current fuel fraction has a
supercruise range between 90-125 miles.
Riccioni was at Northrop from 1976 onwards I believe.
 
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