Northrop / McDonnell Douglas ATF - YF-23 and EMD F-23

[Steve Pace]

Thank you.

 

[Stargazer]

Its very easy to overlook this fact but YF-23 used 100% of its larger tails control surfaces in both Pitch, Yall and Roll, while YF-22 TVC only works in pitch and the aircraft has to deal with its huge vertical stabilizing effect and inertial dead weight and drag when maneuvering.

Part of this sentence can't be read. Can you fix that?

 

[lantinian]

Its very easy to overlook this fact but YF-23 used 100% of its larger tails control surfaces in both Pitch, Yall and Roll, while YF-22 TVC only works in pitch and the aircraft has to deal with its huge vertical stabilizing effect and inertial dead weight and drag when maneuvering.

Part of this sentence can't be read. Can you fix that?

Done. Thanks for asking

 

[bring_it_on]

Another article from the archives..

Expensive Fight For ATF Contract ;Bidders Forced to Foot Bill In Race to Build Jet Fighter - The Washington Post 4/26/1987

It was, as industry officials describe it, unusually blunt talk coming from a ranking Pentagon official. Meeting with the chief executives of the country's largest aerospace firms three weeks ago, Air Force Chief of Staff Larry D. Welch responded to the industry's growing complaints about the Air Force's Advanced Tactical Fighter (ATF) program-the high-stakes competition to build the new jet fighter of the 21st century.

"The whole pitch was to quit bellyaching about the rules and get to work and build me an airplane-or get out of the program," said one highly placed industry executive, who asked not be identified. "We got the message loud and clear."

Welch in an interview last week flatly denied that he ever told the contractors to "quit bellyaching" and contended that the session with the executives was entirely "amicable." But he added, "Their concerns did come out at the meeting."

Whatever the tone of the meeting with Welch, the more dramatic accounts now circulating in defense industry circles underscore the extent to which ATF has turned into the most closely watched and controversial new weapons program at the Pentagon.

The yet-to-be-built airplane, once primarily considered a high-tech marvel, is invariably described as a "revolutionary" breakthrough in military aviation. But in recent months, it has also become an industry cause celebre, a symbol of a new Pentagon procurement process that is rapidly changing the ground rules under which defense contractors operate.

Those ground rules, shaped in part by last year's reform proposals of the presidentially appointed Packard Commission, include a litany of features that are transforming the defense business: competition for highly coveted awards, the encouragement of teaming arrangements among prime contractors and, perhaps most financially costly for contractors, requirements that they foot the bill for large portions of the research and development costs of new weapons systems.

"The ATF program has become a cornerstone of the debate over what the defense industry should look like," said David J. Smith, a securities analyst with Alex Brown & Sons Inc. who specializes in defense stocks. "It's become a lightening rod for these new procurement rules . . . {which} are being used as a club over the industry."

The debate is further heightened by the enormous stakes involved in ATF, a program that ultimately will cost as much as an estimated $65 billion over the next 15 to 20 years. Last October, after sifting through seven proposals, the Air Force selected two rival teams of contractors-one headed by Northrop Corp., the other by Lockheed-California Co.-to build ATF prototypes during a 50-month "demonstration/validation" phase.

The rivals are believed to be investing a combined total of up to $1 billion to win the contract. After a fly-off between the two models in 1990, the Air Force will select a winning team, which is supposed to begin making the first of a planned 750 deliveries in 1993. According to some reports, the Navy is also planning to buy an additional 522 of the airplanes, thus further raising the stakes in the ATF competition.

Winning this one has thus been described in perhaps hyperbolic terms as a near make-or-break proposition for some of the country's aerospace giants-at least in terms of maintaining their historic role as makers of jet fighters.

"It's a high-risk poker game," said Michael Burch, vice president of McDonnell Douglas Corp., which has hopped aboard the Northrop team. "If we don't win this competition, we've got no new {military aircraft} business coming down the road, and we'll have invested $250 to $300 million of our own money. We can't afford to go through too many competitions like this."

"It may sound like a platitude, but this really is the only game in town," says Sherman N. Mullin, vice president and ATF program manager for Lockheed-California Co., whose team includes General Dynamics Corp. and Boeing Corp. "In this business, the number of new starts of military aircraft has been going down. Where you used to have dozens per decade, now you're down to one or two."

The problem, as many industry officials and financial analysts see it, is that the companies are being required to put up huge sums upfront without guarantees that they will be able to recoup their investments. Even for the team that is selected to begin full-scale production, there is the implicit threat that the Air Force will choose to "dual-" or "split-" source the airplane, forcing the winning contractors to divide the rewards with another bidder on a year-by-year basis.

Then there is always the fear that a new Democratic administration in 1989 or a more liberal Congress skeptical of Pentagon claims could decide the whole program is not worth the money and either sharply scale it down or cut it out altogether. Some critics have suggested that some of the high-tech computers and electronic circuitry that are supposed to be a part of ATF can be just as easily placed in retrofitted F15s, for a fraction of the cost.

To some, such uncertainties are no different than those facing any corporation that develops new products in an unpredictable marketplace. But for a defense industry that has long been used to a cozy relationship with its only customer, such vagaries are hard to adjust to.

"The two groups are going to invest upwards of a billion dollars on an airplane that they may never get to build," says John Simon, a securities analyst with Sidler Amdec Securites Inc. in Los Angeles. "I don't think that's very good business, and neither does the stock market."

"The rules are preposterous," adds Smith of Alex Brown. "You have an industry that is being forced to spend whatever is necessary with no guarantee of an award-and not even an understanding that there will be an award . . . . It's disastrous."

The Air Force, for its part, contends that many of these concerns are grossly overstated-in part for political effect by the industry. Welch said last week that any discussion of a possible split-sourcing of the aircraft is "speculation" about a decision that is "far, far off" in the future.

Moreover, other Air Force officials have pointed out that all the ground rules and conditions of ATF were well known to the participants when they entered the competition. If the companies didn't like the rules, nobody forced them to play the game.

"We've been straight and aboveboard, and industry shouldn't have any reason to gripe," argues Anthony de Luca, the Air Force's deputy competition advocate.

In fact, the industry griping is to some extent belied by what Lockheed's Mullin acknowledges is the "intensity" of the ATF battle, rivalry that has dominated and excited much of the sprawling aerospace community here in southern California.

The technological features of ATF alone have been a source of excitement and enthusiasm in the industry, as is readily apparent from glancing at some of the literature being churned out by the rival teams and by talking to some of the participants here. Both of the teams have set up expensive flight simulators to test their ATF models. Northrop's simulator includes a set of video display panels, resembling a video game arcade, in which mock pilots simulate aerial dog fights with the ATF.

The ATF, the company said in its recent annual report, contains characteristics that are "as distant from the most advanced fighters flying today as jet-powered fighters were from the propeller planes of World War II."

Al Pruden, Lockheed's director of tactical air requirements and a recently retired Air Force general, thinks that may be overstating the case. But, as a former F15 pilot, he makes clear that the proposed aircraft is nonetheless a jet jockey's dream, a super-sophisticated, high-tech flying machine that represents a dramatic advance over anything in the skies today.

"It's going to be a revolutionary aircraft; it's going to make quantum leaps in avionics performance," said Pruden in a recent interview at Lockheed-California headquarters in Burbank. "One thing ATF is going to be able to do is cruise supersonically without using afterburner, which means it's going to be much more efficient at supersonic speeds . . . . And in terms of avionics capability, it's going to be twice as reliable as any current aircraft."

Mostaerospace experts agree that there are always problems and uncertainties when developing expensive pieces of equipment with cutting edge technology. But industry officials argue that those problems are exacerbated by specific terms in the Air Force contracts.

Each of the two teams received what are known as "firm fixed price" contracts worth $691 million each. Firm fixed price means that is all the two groups will get-anything extra they spend must come out of their own coffers with no reimbursement from the Pentagon.

Yet the Air Force readily concedes that $691 million is significantly short of the cost of building the prototype, much less whatever extras the teams might include to beat the competition. Current estimates are that each of the two rivals will spend between $300 million to $500 million that won't be reimbursed by the government.

Yet that doesn't mean the money will come out of the coffers of Lockheed, Northrop and the other participants.

"It will just flow down through our customer base," says Marv Elkin, vice president for marketing and materials for Northrop. "We're going to attempt to negotiate cost sharing on each of our subcontracts . . . . We've made it clear in our request for proposals that we want cost sharing."

Elkin said Northrop plans to award ATF subcontracts for less money than the value of the work with the expectation that the winning bidder will pay for the rest out of his own money. Each of the two teams is planning to award 300 to 400 subcontracts over the next few months, but already there are reports that many subcontractors are unhappy.

After requesting competitive bids, both teams recently awarded major subcontracts for the aircraft's radar to a team consisting of Westinghouse and Texas Instruments. But according to a knowledgeable industry source, Hughes Aerospace, one of the main competitors, deliberately submitted a bid that was insufficient to win the subcontract. The reason, according to the source, is that the company concluded the cost sharing required to win the subcontract wasn't worth it.

"There's a lot of grumbling among the subs, and you see some guys saying, `I'm not interested in getting into this business,' " says an executive of one of the teams, who preferred to remain anonymous.

How all this will sort out in the long run remains unclear. But even industry officials acknowledge that, in a tighter defense spending environment, the Pentagon's strategy may make sense for all concerned. If the Air Force had to request appropriations for the full cost of the ATF competition, Congress might not provide it, and industry would get nothing.

Moreover, by setting up the contract this way and by requiring that it be competitive, the Air Force is maximizing the political constituency behind ATF, noted one lawyer who represents defense contractors. More companies, having invested more of their own money, will have more of an incentive to lobby Congress to keep ATF going.

"It's almost diabolical," said the lawyer. "They're deliberately underfunding . . . as a way of putting a kind of pressure on the Congress." CAPTION: Artist's concept of the Air Force's yet-to-be-built Advanced Tactical Fighter.

 

[flanker]

YF-23 and TACIT BLUE moved to new hangar; http://www.daytondailynews.com/gall...e-museum-new-building-gets-first-plane/gCXLY/

The scrolling in the album is downright retarded, three ways of scrolling through the pics and only one works. Use the arrows on top with the numbers.

Hopefully there will be some sweet YF-23 & TACIT BLUE family pics...

Some high res pictures here; http://www.nationalmuseum.af.mil/Upcoming/Photos.aspx?igpage=1

 

[bring_it_on]

I'll be visiting Dayton and the museum around thanksgiving. Also, Paul Metz is doing a presentation on the F-22/ATF on the first of December. Hopefully someone here can attend but they do post both audio and video.

Lectures

 

[FighterJock]

Did a search on Google for the YF-23 and this site came up http://yf-23.net/index.html

I just thought I would share it.

 

[lantinian]

Did a search on Google for the YF-23 and this site came up http://yf-23.net/index.html

I just thought I would share it.

Go back 1 page into this tread and you will even find a post by the site maker.

 

[FighterJock]

Did a search on Google for the YF-23 and this site came up http://yf-23.net/index.html

I just thought I would share it.

Go back 1 page into this tread and you will even find a post by the site maker.

First site on the YF-23 I saw on Google when I was searching around for the YF-23. By the way it was my favorite ATF above the F-22 and I was gutted that it was not chosen back in 1992.

 

[Stargazer]

Did a search on Google for the YF-23 and this site came up http://yf-23.net/index.html

I just thought I would share it.

I know it's quite a long thread but this site has been mentioned many times before already. Thanks anyway.

 

[Ogami musashi]

This article by dave mumjabar sheds some light on Barry watts comments about the ability of the F-23 to supercruise for the entire mission. The fact that jim sanberg confirms it is cool but you may wonder what was really the role played by watts in the F-23 program.

F-23 — The Super Fighter America Never Built

The Lockheed Martin F-22 Raptor is the best air superiority fighter ever built, but could America have done better? When the YF-22 prototype won the contract for the Advanced Tactical Fighter in April 1991, it was a lesser plane compared to the Northrop YF-23 in many ways. Though the YF-22...

warisboring.com

On another note, i apologize for the questions sent to jim sandberg and paul metz, but my last correspondance with the WMOF was that they would print the questions and give them to both pilots but then i hear no news from them...

 

[sferrin]

“Supercruise is impressive on paper but not very practical in a fighter with limited fuel,” a senior Air Force F-22 pilot said. “I would much rather have an aircraft that accelerates and gains energy back quickly than one that supercruises.”

Love it when they don't give names. Lends all sorts of credibility and such.

 

[Sundog]

“Supercruise is impressive on paper but not very practical in a fighter with limited fuel,” a senior Air Force F-22 pilot said. “I would much rather have an aircraft that accelerates and gains energy back quickly than one that supercruises.”

Love it when they don't give names. Lends all sorts of credibility and such.

It's also weird hearing that, because it doesn't give the speed range where it supposedly accelerated faster than the YF-23. One of the metrics I've always seen used is acceleration from Mach .9 to Mach 1.2. The YF-23 could pass through the transonic range without afterburner, whereas the YF-22 couldn't. Given that they both had the same engines, though the integration is different, leads one to conclude that the YF-23 had lower drag than the YF-22, at least lower wave drag. Also, in aerodynamics, wave drag usually replaces form drag at high speed, and I don't see the form drag being that much higher. Also, the YF-22 would have had higher interference drag. Maybe the YF-23 had higher boat tail drag if this is true?

Also, I would like to see how much slower the reported acceleration actually was; are we talking a couple of seconds or tens of seconds? We know both aircraft met the maneuvering and performance specs, so, for the most part, I see it as a non-sequitur. We already know Northrop lost based on management, not performance and that the YF-23's actual performance is still classified. We also know that the USAF tends to prefer LO over anything else now and the YF-23 beat the YF-22 in that regard, so I'm still not sure why this issue is even being brought up.

 

[overscan (PaulMM)]

“Supercruise is impressive on paper but not very practical in a fighter with limited fuel,” a senior Air Force F-22 pilot said. “I would much rather have an aircraft that accelerates and gains energy back quickly than one that supercruises.”

Love it when they don't give names. Lends all sorts of credibility and such.

It's also weird hearing that, because it doesn't give the speed range where it supposedly accelerated faster than the YF-23. One of the metrics I've always seen used is acceleration from Mach .9 to Mach 1.2. The YF-23 could pass through the transonic range without afterburner, whereas the YF-22 couldn't. Given that they both had the same engines, though the integration is different, leads one to conclude that the YF-23 had lower drag than the YF-22, at least lower wave drag. Also, in aerodynamics, wave drag usually replaces form drag at high speed, and I do't see the form drag being that much higher. Also, the YF-22 would have had higher interference drag. Maybe the YF-23 had higher boat tail drag if this is true?

Also, I would like to see how much slower the reported acceleration actually was; are we talking a couple of seconds or tens of seconds? We know both aircraft met the maneuvering and performance specs, so, for the most part, I see it as a non-sequitur. We already know Northrop lost based on management, not performance and that the YF-23's actual performance is still classified. We also know that the USAF tends to prefer LO over anything else now and the YF-23 beat the YF-22 in that regard, so I'm still not sure why this issue is even being brought up.

I didn't read it as a criticism of YF-23 versus YF-22 but simply saying he didn't see value in supercruise due to high fuel consumption. This makes no sense really as the entire purpose of supercruise was to fly supersonically without burning too much fuel. Now, it is likely that supercruise requires, say, full military thrust rather than economic cruise thrust, but you travel perhaps twice as fast, so the distance covered should be greater unless the rate of fuel burn is more than doubled in supercruise from economic subsonic cruise.

MiG-25 and MiG-31 carry much more fuel because they fly supersonically only with the addition of afterburner which increases fuel consumption MUCH more than supercruising in dry thrust.

Having said that I think F-22 is rather short on fuel.

 

[Ogami musashi]

I didn't read it as a criticism of YF-23 versus YF-22 but simply saying he didn't see value in supercruise due to high fuel consumption. This makes no sense really as the entire purpose of supercruise was to fly supersonically without burning too much fuel. Now, it is likely that supercruise requires, say, full military thrust rather than economic cruise thrust, but you travel perhaps twice as fast, so the distance covered should be greater unless the rate of fuel burn is more than doubled in supercruise from economic subsonic cruise.

MiG-25 and MiG-31 carry much more fuel because they fly supersonically only with the addition of afterburner which increases fuel consumption MUCH more than supercruising in dry thrust.

Having said that I think F-22 is rather short on fuel.

I read it like you. One the supercruise thing. It impacts the range because of two things. First supercruise requirement, engine wise, is for certain supersonic thrust. The thrust increase with speed is not linear (it is often less than that) so you need a non linear higher engine rating to achieve it. The next thing is that the SFC increases with speed and one thing that makes an engine a supercruising engine is the limitation of the increase of SFC with speed and especially in supersonic.

I too think the quote "from a senior pilot" is not the general feeling within the raptor community. Also, even from the early days of the ATF program the supercruise leg was around 100miles+ 4 combat turns. Sure if the raptor was still with 12t internal fuel it could go much farther but the operational concept means it would use that range for more subsonic leg. A slide from LM (present in this thread) that shows the range of the F-22 with a 100 miles supercruise leg both on internal and external fuel just highlights that.

Now that the F-23 was to be capable of supercruise the whole sortie is quite impressive and honestly i have some doubts about it but if J.sanberg confirmed it..well that sure is true.

 

[sferrin]

Having said that I think F-22 is rather short on fuel.

IIRC the difference in fuel between the YF-22 and the F-22A is 5,000 to 7000 pounds. (Don't recall which. Just remember back in the day the fuel for one of the designs was given as ~23,000lbs and the other was ~25,000lbs. The F-22A is just short of 19,000lbs. Apparently it can't fly with the 4 tanks either like they were planning.)

 

[Colonial-Marine]

Apparently it can't fly with the 4 tanks either like they were planning.)

According to whom?

 

[sferrin]

Apparently it can't fly with the 4 tanks either like they were planning.)

According to whom?

People over on F-16.net. You'll also note we never saw any test flights with them nor have we seen them in service with them, even when they are crossing oceans.

 

[Steve Pace]

Having said that I think F-22 is rather short on fuel.

IIRC the difference in fuel between the YF-22 and the F-22A is 5,000 to 7000 pounds. (Don't recall which. Just remember back in the day the fuel for one of the designs was given as ~23,000lbs and the other was ~25,000lbs. The F-22A is just short of 19,000lbs. Apparently it can't fly with the 4 tanks either like they were planning.)

I've seen three tanks on F-22As - when they ferried to Hawaii. -SP

 

[sferrin]

Having said that I think F-22 is rather short on fuel.

IIRC the difference in fuel between the YF-22 and the F-22A is 5,000 to 7000 pounds. (Don't recall which. Just remember back in the day the fuel for one of the designs was given as ~23,000lbs and the other was ~25,000lbs. The F-22A is just short of 19,000lbs. Apparently it can't fly with the 4 tanks either like they were planning.)

I've seen three tanks on F-22As - when they ferried to Hawaii. -SP

Any chance of a picture? All I've seen had two. Seems odd they'd have two 600 gallon tanks on one wing and only one on the other. And then fly a long distance that way.

 

[kilokb]

You wouldn't happen tohave any evidence of that would you.? : I'm very skeptical

 

[bobbymike]

America's F-23 Stealth Fighter vs. the Lethal F-22 Raptor: Who Wins?

America's ultmate fighter showdown. Who would have won?

nationalinterest.org

 

[Gridlock]

Didn't *someone* mention that RAT55 had been seen with F22s carrying unusual externals? Albeit in Death Valley, obviously.

 

[Sundog]

Didn't *someone* mention that RAT55 had been seen with F22s carrying unusual externals? Albeit in Death Valley, obviously.

That was Quellish.

 

[lantinian]

Having said that I think F-22 is rather short on fuel.

IIRC the difference in fuel between the YF-22 and the F-22A is 5,000 to 7000 pounds. (Don't recall which. Just remember back in the day the fuel for one of the designs was given as ~23,000lbs and the other was ~25,000lbs. The F-22A is just short of 19,000lbs. Apparently it can't fly with the 4 tanks either like they were planning.)

Indeed. Around 1994 I think it was found the F-22 could no meet its maneuvering requirements at altitude. There were 3 solutions.
A. Spend a whole lot more to strengthen the airframe while keeping it the same wight
B. Relax the maneuvering requirement but keep the amount of fuel it carried
C. Reduce the range requirements but enable it to meet its maneuvering requirements.

Well, they went with C.

The original ATF requirement never called for the fighter to supercruise the whole way but the YF-23 did. I think they asked for supercruise only 1/3 of the way,
I also believe YF-23 wouldn't have the above fuel fraction problems since the EMD proposal was an evolution of a well understood design, not one made by combining 3 companies proposals.

 

[sferrin]

Having said that I think F-22 is rather short on fuel.

IIRC the difference in fuel between the YF-22 and the F-22A is 5,000 to 7000 pounds. (Don't recall which. Just remember back in the day the fuel for one of the designs was given as ~23,000lbs and the other was ~25,000lbs. The F-22A is just short of 19,000lbs. Apparently it can't fly with the 4 tanks either like they were planning.)

Indeed. Around 1994 I think it was found the F-22 could no meet its maneuvering requirements at altitude.

Well how did it meet them during the flyoff? And if it failed to meet the requirement why didn't Northrop ever point that out? ???

 

[lantinian]

Having said that I think F-22 is rather short on fuel.

IIRC the difference in fuel between the YF-22 and the F-22A is 5,000 to 7000 pounds. (Don't recall which. Just remember back in the day the fuel for one of the designs was given as ~23,000lbs and the other was ~25,000lbs. The F-22A is just short of 19,000lbs. Apparently it can't fly with the 4 tanks either like they were planning.)

Indeed. Around 1994 I think it was found the F-22 could no meet its maneuvering requirements at altitude.

Well how did it meet them during the flyoff? And if it failed to meet the requirement why didn't Northrop ever point that out? ???

The Yf-22 vs Yf-23 Dem/Val was not a fly off but a demonstration and validation of specific points in each team proposals. The teams were even free to decide to test which ones.
As far as I am aware flying 1/3 of the full mission in Supercruise or doing 9G at 50,000 ft were not part of Lockheed YF-22 test points

My whole point was that is we were to score the F-22A today on the green, yellow, red cards of Donald Rice, the F-22 would not have gotten all green on meeting all USAF requirements.
Actually, the F-22 would have gotten reg on the range and yellow on the supercruise, given it overheats when doing supercruise for more than 30 min.

 

[sferrin]

What about the statement we always see, "both aircraft met all the requirements". This is the first I've heard the YF-22 did NOT meet all the requirements. Do you have any sources for that?

 

[lantinian]

What about the statement we always see, "both aircraft met all the requirements". This is the first I've heard the YF-22 did NOT meet all the requirements. Do you have any sources for that?

I tried to be very specific that the EMD F-22 did not meet its performance requirements, not YF-22
The all green given to both programs was not for the YF-22 and YF-23 but for the EMD proposals submitted by both team backed up by the data of the Dem/Val test vehicles.

I've pointed the F-22 performance issue before

http://www.secretprojects.co.uk/forum/index.php/topic,4505.msg48047.html#msg48047

Somebody at the time pointed that article as reference
https://www.flightglobal.com/news/articles/f-22-weight-increase-agreed-26820/.
but I read about it in a book.

By the way, the F-22 EMD proposal Lockheed/Boeing/General Dynamics submitted at 1991 also didn't meet Lockheed own LO numbers for it, as evident by the full redesign of the saw tooth edges of all access panels on the aircraft at the CDR around 1994 too. I vividly remember a 5 or 6 view of the F-22 before the redesign and you can see it had 2x the number of saw tooth edges on panel and bay doors.

 

[sferrin]

What about the statement we always see, "both aircraft met all the requirements". This is the first I've heard the YF-22 did NOT meet all the requirements. Do you have any sources for that?

I tried to be very specific that the EMD F-22 did not meet its performance requirements, not YF-22

Did they change them? I'd have thought the contenders would be a bit upset if after the design was selected the customer said, "wait, we're changing the requirements now".

 

[lantinian]

Yes, around 1995 USAF secretly relaxed the F-22 range requirement so the design can maneuver as hard as it needs, and fly as fast as it needs but with less fuel.

It seams we've been over how fuel has changed in the F-22 design earlier in this tread

http://www.secretprojects.co.uk/forum/index.php/topic,1092.msg25077.html#msg25077

Its interesting how Northrop specifically designed YF-23 to considerably exceed the ATF required supercruise in terms of range, time and speed, while at the end of the day, F-22 even didn't meet the range and time part.

 

[lantinian]

Yep. My theory is they decided they're not going to have to go tankerless as long cruising around in badguy territory so they cut down the fuel load to enable even higher performance. Granted, the production engines contribute to that but the F-22A is considerably slimmer than the YF-22.

No the fuel was lost as weight cutting measures during the development. The F-22A has not gained any performance because of it and has lost the ATF RFP radius of action. The whole point of the ATF was to have a stealthy, supercruising aircraft which combined with the latest avionics would be a super air combat platform. Aircraft limitations have seen the fuel cut so it can only supercruise to a radius half that required in the RFP. 410 Nm vs 750-800 NM. This is not a recasting of the RFP due to changed circumstances but a failure of the development team to produce the goods.

My question is could the F-23 have retained the RFP fuel and radius levels?

I don't think anybody replied to that question 8 years ago but since its relevant now, I would say I more convinced now than ever than the answer is YES.

 

[sferrin]

Yes, around 1995 USAF secretly relaxed the F-22 range requirement so the design can maneuver as hard as it needs, and fly as fast as it needs but with less fuel.

What does that mean specifically? Did they decide that the maneuver and speed requirement (that the YF-22 met) was not sufficient? And if it's "secret" how is it that you know about it?

 

[Ogami musashi]

Honestly, i've never seen any clear evidence of the F-22 failing at requirements. The article you mention in 1995 (1) do mentions weight increase that resulted in diminished performance but nothing on the scale of what you suggest lantinian.

To me there's a gap between the pre-contract attribution numbers and the F-22 development, the latter being pretty obscure by the way (for example, it seems the big weight increase from 15tonns to 19,7tons, dated as late as 2000) which means i think we don't know when the numbers were changed and for what reason.

As far back as 1986 the requirements, including subsonic radius, were changed (2) to keep to plane into the 50 000 lbs take of weight. Back in 1991 the program accepeted a weight increase (3) and finally in before the design freeze a number of features and requirements, again with subsonic radius being altered were changed to account for cost challenges (4).

The Final F-22 design was only frozen in 1995 and what happened next is not clear.

So in this context it is very hazardous to say if the F-23 would have fared better but most important, what were the absolute values of supercruising range with the F-23.
Last but not least, remember the F-23 version we have dates from 1990, at least several years before the F-22 design was frozen which means another version of the F-23 could have shown up with very different specs.

Ref:

1:"F-22 weight increase agreed", Flight Global, 1244, 1995
2:"ATF:balance tipsthe scales", Flight Global, 3304, 1986
3: "AIRCRAFT DEVELOPMENT Reasons for Recent Cost Growth in the Advanced Tactical Fighter Program", GAO report, NSIAD-91-138, 1991
4: "TACTICAL AIRCRAFT Restructuring of the Air Force F-22 fighter program", GAO report,NSIAD-97-156, 1997

 

[lantinian]

1st...we should probably move the last few replies to the F-22 Topic

It will take me a while to find where I've read that the range requirements were relaxed "secretly" since it was more than 10 years ago...possibly longer.

Even without that, the facts are quite clear and can lead you to the same conclusion ...

Early reports, said the F-22 will have an empty weight of 14,365kg, yet it ended up with 19,700kg. A 46% increase.
At the same time, internal fuel figures dropped from 25,000 lb in YF-22, to 20,650 lb in early F-22A reports to the now officially confirmed 18,000 lb. A 12% decrease.

Both of these developments affected negatively the expected range the F-22 was projected to have in 1991.
So at the time of the CDR in 1994, somebody must have told the USAF. As there was a significant political battle at the time to keep the F-22 program alive, admitting publicly the F-22 cannot meet its range requirements was the last thing USAF wanted to do....So they "relaxed" them.

Quite logical outcome if you start with a fixed volume and you trade off empty space to increase structure strength or simply add more systems... Both of which happened multiple times during the EMD phase.

 

[quellish]

Actually, the F-22 would have gotten reg on the range and yellow on the supercruise, given it overheats when doing supercruise for more than 30 min.

Do you have a source for that?

 

[Ogami musashi]

1st...we should probably move the last few replies to the F-22 Topic

It will take me a while to find where I've read that the range requirements were relaxed "secretly" since it was more than 10 years ago...possibly longer.

Even without that, the facts are quite clear and can lead you to the same conclusion ...

Early reports, said the F-22 will have an empty weight of 14,365kg, yet it ended up with 19,700kg. A 46% increase.
At the same time, internal fuel figures dropped from 25,000 lb in YF-22, to 20,650 lb in early F-22A reports to the now officially confirmed 18,000 lb. A 12% decrease.

Both of these developments affected negatively the expected range the F-22 was projected to have in 1991.
So at the time of the CDR in 1994, somebody must have told the USAF. As there was a significant political battle at the time to keep the F-22 program alive, admitting publicly the F-22 cannot meet its range requirements was the last thing USAF wanted to do....So they "relaxed" them.

Quite logical outcome if you start with a fixed volume and you trade off empty space to increase structure strength or simply add more systems... Both of which happened multiple times during the EMD phase.

The thing we are discussing here is if the F-22, by its design, couldn't meet the ATF first projected requirements while the F-23 could. What you are asserting here is not in accordance with the sources i provided and the reason is that the increase in weight you talk about, is very likely to have occured in the early 00's due to air-to-ground requirements and thus do not translate into a bad design but instead in a late minute specification change that of course had negative impacts.

(1) quotes explicitly that requirements changed in 00 and that strengthening of the airframe was necessary. One year later, another strengthening was again necessary (2).
If you look at the figure 3.6 in (3) you'll see that the ratio of projected weight to achieved weight has a linear curve all the way to 2001 which indicates that the projected weight didn't change otherwise you would have seen a break in the curve. And if you compute the percentage at max you are 20% above. If we take 1992 as the weight reference, the projected empty weight was then less that 13,98 tons (ref (1) in previous post). With a 20% around 2001 (that is including the strengthening) we are at 16,7 tons. However as decpited in table 2 of (4), raptor 4012 rolled out in 2003 had an empty weight of 19,56 tons and the weight continued to increased after (same table).

This likely means something happened around 2001-2004 when the airforce actually tested the air-to-ground modifications and not during the 1992-1998 period as you suggest.

As for the fuel loads, the only fact we know is that from the start the F-22 had lower fuel than the YF-22. That is not proving anything regarding our question as the F-23 to YF-23 fuel ratio is unknown.

All of this do not speak in favor of a failure of LM to meet requirements in the course of the developpment other than on costs/expansion to a2G grounds.

So i'd be glab if you find the sources for that "secret" downgrade of requirements.

ref:

(1) "TACTICAL AIRCRAFT F-22 Development and Testing Delays Indicate Need for Limit on Low-Rate Production", GAO-01-310, 2001.
(2) "TACTICAL AIRCRAFT F-22 Delays Indicate Initial Production Rates Should Be Lower to Reduce Risks", GAO-02-298, 2002.
(3) "Lessons Learned from the F/F-22 and F/A-18E/F Development Programs", ISBN 0-8330-3749-8, 2005.
(4) "F-22A Multiyear Procurement Business Case Analysis", IDA P-4116, 2006.

 

[lantinian]

Actually, the F-22 would have gotten reg on the range and yellow on the supercruise, given it overheats when doing supercruise for more than 30 min.

Do you have a source for that?

No one that I am able to find out at the moment....sorry it was many year ago.

What I remember reading is that because of the closely coupled engines of the F-22, heat build up between the engines during supercruise could not be attenuated effectively and the aircraft operationally had to be limited to about 30 min of supercruise. I can't remember if the heat build up was a safety issues or a stealth one.

Another thing.
Wikipedia lists F-22 range as 820 nmi of which 200 nmiles are in supercruise
Contrast this to recent statement from Gene Sandberd that YF-23 can do the entire mission in supercruise.

 

[lantinian]

The thing we are discussing here is if the F-22, by its design, couldn't meet the ATF first projected requirements while the F-23 could. What you are asserting here is not in accordance with the sources i provided and the reason is that the increase in weight you talk about, is very likely to have occured in the early 00's due to air-to-ground requirements and thus do not translate into a bad design but instead in a late minute specification change that of course had negative impacts.

(1) quotes explicitly that requirements changed in 00 and that strengthening of the airframe was necessary. One year later, another strengthening was again necessary (2).
If you look at the figure 3.6 in (3) you'll see that the ratio of projected weight to achieved weight has a linear curve all the way to 2001 which indicates that the projected weight didn't change otherwise you would have seen a break in the curve. And if you compute the percentage at max you are 20% above. If we take 1992 as the weight reference, the projected empty weight was then less that 13,98 tons (ref (1) in previous post). With a 20% around 2001 (that is including the strengthening) we are at 16,7 tons. However as decpited in table 2 of (4), raptor 4012 rolled out in 2003 had an empty weight of 19,56 tons and the weight continued to increased after (same table).

This likely means something happened around 2001-2004 when the airforce actually tested the air-to-ground modifications and not during the 1992-1998 period as you suggest.

As for the fuel loads, the only fact we know is that from the start the F-22 had lower fuel than the YF-22. That is not proving anything regarding our question as the F-23 to YF-23 fuel ratio is unknown.

All of this do not speak in favor of a failure of LM to meet requirements in the course of the developpment other than on costs/expansion to a2G grounds.

So i'd be glab if you find the sources for that "secret" downgrade of requirements.

ref:

(1) "TACTICAL AIRCRAFT F-22 Development and Testing Delays Indicate Need for Limit on Low-Rate Production", GAO-01-310, 2001.
(2) "TACTICAL AIRCRAFT F-22 Delays Indicate Initial Production Rates Should Be Lower to Reduce Risks", GAO-02-298, 2002.
(3) "Lessons Learned from the F/F-22 and F/A-18E/F Development Programs", ISBN 0-8330-3749-8, 2005.
(4) "F-22A Multiyear Procurement Business Case Analysis", IDA P-4116, 2006.

I accept that all air to ground requirements were added after 1991 but I am 100% sure that I read that around 1995, it was found F-22 could not meet certain performance parameters related to maneuvering at 50k feet due to increased weight and that USAF decided to decrease the range requirement in order for the aircraft to carry less fuel and hence weight less.
That happened after JDAM air to ground requirement was added.

Here is a reference I could find that points to the issue of weight vs performance.

F-22 Aircraft: Progress in Achieving Engineering and Manufacturing Development Goals (Letter Report, 03/10/98, GAO/NSIAD-98-67)

www.globalsecurity.org

That's from March 1998.

...aircraft empty weight is a subparameter that affects the supercruise, acceleration, maneuverability, and combat radius performance parameters. Although the aircraft's empty weight is currently expected to be 2 percent higher than the established goal for that subparameter, Air Force analyses indicate that the increased weight is not significant enough to cause the estimates for the affected parameters to not meet their goals.

I checked all 6 books I own specifically written for the F-22 plus 1 long F-22 related article. All published after March 98. They all point to an emplty weight of 14.5t

The best reference is from Air International, December 98, page XIV

Emtpty weight was been allowed to "float" from 13,980kg at the Preliminary Design Review of 1992 to 14,365kg, a figure which had minimal affect on performance.

This a about a 2.5% increase. Was this the GIO report talked about?

Well, empty weight is now 19,700kg. That's a 40% increase?
Performance was affected.... acceleration most of all and range for sure.

The newest of the books... by Jay Miller published 2006, page 102, lists YF-22 radius of action as 750-800 nm (ATF target) and F-22A as 450 nmiles, ATF was to supercruise about 250-300nm in both directions, yet F-22A can do only 100 nm. That's RED card by anyone's standard.

How did USAF accepted this outcome and why was the discrepancy never explained?
Because they wanted to protect the F-22, which they barely did. Had the F-22 weight growth been disclosed publicly, the way F-35 weight growth is, the program would likely not have survived.

Why do I think F-23A could have better met that 750 nm radius of action requirement?
1. Recent Statements by Gene Sandberd that YF-23 could fly its entire mission in supercruise. Nobody has claimed anything close to about the Raptor.
2. YF-23 carried 1000lb less fuel than YF-22, yet claimed the same range, while being heaver design on paper. That speaks of a more efficient airplane.
3. The YF-23 design was a much more mature one. You can trace its origin all way back to Northrop 33,255lb Agile ATF design submitted as part of RFI in 1982. Northrop never did a substantial redesign, only an improvements into the basic concept. The YF-23 design was actually done in yearly 1986 before prototypes for the Dem/Val phase were even requested and as a result retained the oversized nacelles for trust reversers even though it would have had better speed and range without them. Northrop actually had to delay its first flight by 6 months to allow Lockheed to catch up.
4. Lockheed YF-22 design was done in 3 months in end of 1987 with the design unfrozen again in early 1988 to reduce supersonic trim drag after the trust reversers requirement was removed.

2,3 and 4 are from Advanced Tactical Fighter to F-22 Raptor: Origins of the 21st Century Air Dominance Fighter, by far the best book on the matter.

 

[marauder2048]

I tjhink you are using contractor responsible weight (empty weight - engines), empty weight and operating empty weight figures interchangeably. Not your fault as many of the sources are unclear. And then you have to estimate
F119 empty weight as well which RAND indicates is around 1800 kg.