Forum: Modern Military Aircraft

Last edited by falcon17 on Dec 28, 2011 - 12:32 AM; edited 1 time in total

Was this aircraft the better choice over the raptor? Pardon me for not clarifying. I've read a thread from above top secret and a few other forums stating that the YF-23 was actually the better choice and that the air force chose second best.

F-16.net Sponsor

Obviously not or it would have won!?

TEG

Apparently it lost out because the F-22 was a better overall fighter. From everything I've read, the F-22 had superior turn rates, both sustained and instantaneous. The YF-23 I've read had superior stealth characteristics, however. I believe the thrust to weight was about the same on both aircraft.

The YF-23 was ahead of it's time but a little too early. So it lost to an overall 'better' fighter.

That_Engine_Guy wrote:

Obviously not or it would have won!?

TEG

Wrong, politics supersedes reality.

I have heard that another factor in play at the time of the decision was the state of Northrup at the time. Apparently there was some lack of belief that the primary contractor would really be able to deliver the complex Y-23 aircraft as promised. The production difficulties with the very complex B-2 were fully underway while the ATF vendor was being chosen and this must certianly have played on the minds of AF officials.

sparky wrote:

Apparently it lost out because the F-22 was a better overall fighter. From everything I've read, the F-22 had superior turn rates, both sustained and instantaneous. The YF-23 I've read had superior stealth characteristics, however. I believe the thrust to weight was about the same on both aircraft.

It was also high-alpha performance afforded by the TVC nozzles that helped enhance the performance characteristics of the YF-22 vis-a-vis the YF-23. As for thrust to weight, it was really a function of which engine was being used. A YF-23 with YF-120 engine was absolutely unstoppable and had an undisclosed top speed and impeccable performance in terms of thrust to weight. The same could be said for the F-22 with YF-120.

YF-23 lost because it was the riskier design despite being the more sophisticated and "promising" one in terms of VLO characteristics and high-altitude speed and basic maneuvering performance. Actually, I believe in terms of several high-altitude performance parameters the YF-23 had the YF-22 beat so the YF-22 wasn't exactly better than YF-23 in every conceivable way in terms of maneuvering.

All of this, alongside the fact that there were doubts about Northrop's ability to deliver on their promise made the YF-22 the clear winner.

The thrust vectoring not only helped YF-22 with turning tight circles but also gave it more control when making any kind of maneuver at high altitudes where thin air reduces the effectiveness of flaps & fins. And YF-23's engines had outlet tunnels covered with heat tiles that were a maintenance hassle. And it carried two fewer missiles, and was supposed to release them with a complex mechanism that wasn't even ready to go at the time of the competition and wasn't trusted; not only did it create the possibility of jamming, but a jam involving one missile could block another one as well.

One consideration that wasn't quite fair, because the program had started out as an Air Force program only and the planes had been designed that way, was adaptability for aircraft carriers. For a while the Navy was seriously considering modifying whichever one won the Air Force's competition, which created incentive to choose the one that coincidentally happened to look like it would be easier to navalize.

I don't believe lack of faith in Northrop would really have been a big factor, though. They had a perfectly good track record, and advanced high-security aircraft programs had already been getting more delayed and more expensive "recently" in general, the more the government got involved, so the phenomenon was well known and thus known not to be Northrop-specific. The leader of Lockheed's Skunk Works blamed the government for what was going on with the B-2 and it wasn't even his department/company to defend.

tacf-x wrote:

YF-23 lost because it was the riskier design despite being the more sophisticated and "promising" one in terms of VLO characteristics and high-altitude speed and basic maneuvering performance.

The YF120 was ruled out because of similar concerns; it's 'variable geometry' design was considered too 'risky'.

The USAF opted for the engine that was deemed more 'conventional' and therefore thought to present a lower life-cycle cost.

All valid reasons to pick one engine over another. One must always weigh all the factors required to operate hundreds of engines in an operational environment for decades.

Ask India how those AL-31FPs are working out in their SU-30MKIs? Great thrust to weight ratio, but can't operate them at Red Flag due to engine maintenance concerns? What about combat? or in 20-30 years!?!

Keep 'em flyin' Thumb

TEG

falcon17 wrote:

Was this aircraft the better choice over the raptor? Pardon me for not clarifying. I've read a thread from above top secret and a few other forums stating that the YF-23 was actually the better choice and that the air force chose second best.

Better at meeting the requirements? The YF-23 was faster, and allegedly stealthier than the YF-22. The F-22 on the other hand has demonstrated much higher speeds than did the YF-22, and is also likely stealthier. The F-22 also had greater agility, and better weapons bay layout. The F-23 would likely have been more expensive, and had even greater technical difficulties, so you have to weigh its advantages against these concerns.

southernphantom wrote:

That_Engine_Guy wrote:

Obviously not or it would have won!?

TEG

Wrong, politics supersedes reality.

You've never been on a source selection team, have you? Aircraft win on technical merit, but that merit usually involves a lot more than just raw performance. Cost and manufacturing capability are just as critical.

Folks who claim Lockheed won because of politics are frankly sore losers...

Last edited by aaam on Feb 01, 2012 - 03:38 AM; edited 1 time in total

Roscoe wrote:

southernphantom wrote:

That_Engine_Guy wrote:

Obviously not or it would have won!?

TEG

Wrong, politics supersedes reality.

You've never been on a source selection team, have you? Aircraft win on technical merit, but that merit usually involves a lot more than just raw performance. Cost and manufacturing capability are just as critical.

Folks who claim Lockheed won because of politics are frankly sore losers...

The YF-22-YF-23 competition remains controversial today, and will probably go on forever. Part of the reason I think it remains so is because it was unique in the history of aircraft selections, so much remains unknown and what little has leaked out seems puzzling.

First, unlike most other situations, USAF never said it would select on performance, cost, risk, etc. In fact, it never actually said what it would select on except that it would be at the discretion of the Secretary of the Air Force. What little bit that came out before the air demonstrations was somewhat confusing, given the outcome. Maneuverability had to be as good as the F-16’s best, and both aircraft exceeded the requirement, but thanks to its thrust vectoring, the YF-22 was better at the left edge of the envelope. It would said that extra credit would not be given for exceeding the requirement, but some eyebrows were raised when maneuverability was one of the few things mentioned later in the limited info given out, and that’s part of the basis for the questions over the years. USAF had said that its main concerns were stealth, speed and range/payload and in those areas it was said that the performance of the Northrop/MDD plane was better. Some have said that except for maneuverability in the areas where thrust vectoring was relevant, the YF-23 was better in almost everything else. Sometimes much better, sometimes only somewhat better. It was generally acknowledged that it was definitely stealthier, especially in IR. It was definitely faster. In fact, to this day, the supercruise speed of the YF-23 with YF120 engines remains classified.

As an aside, thrust vectoring does not make you turn tighter, it lets you point the nose independently of the direction of flight better. This is particualry useful on the F-22 as it seems it’ll be another five years before it can use AIM-9X in full High Off Boresight Mode.

The way the competition was run, was that there were a number of requirements. The purpose of the flights was to demonstrate how well the teams could validate their predictions and meet the requirements. A “stoplight” was assigned to each criterion: Red for couldn’t meet. Yellow for met, but with concerns. Green for fully met with no concerns and supposedly for some criteria there was a Blue stoplight for significantly exceeds or special merit in that particular category. The “lights” were not cumulative, and no points were assigned. The aircraft were not to be compared with each other and the evaluation teams were not to compare notes. No one was to fly both aircraft to compare handling. In fact, the only person to ever fly both was Paul Metz (after the ATF competition he left Northrop and went to work for Lockheed) and he has never compared the two. The teams were to make no recommendations to the Secretary, simply report. This meant he was free to use whatever criteria he wanted to make the decision, and the decision has never been fully explained. There was some unofficial talk about “producability”, with some concern regarding Northrop being able to produce certain large scale single piece assemblies. The fact that they had two aircraft sitting there that had done it, plus that they were doing the same for the B-2 was not considered sufficient. Documentation for the YF-23 to F-23 transition program was poorer, MDD afterwards admitted it and we all know that to the gov’t paper is everything. In addition, it was mentioned that the AF was concerned about the Northrop management plan. There will be a slight pause here for the chuckles to die down regarding the irony of the Government passing judgment on anyone else’s management plan.

Regarding the weapons bay layout, we can’t really say which layout was “better”. Northrop didn’t put a launcher in its prototypes. USAF did express some concern regarding the fact that Northrop’s launcher design reportedly used a single arm mechanism, which could end up restricting its ability to launch should it fail or be damaged, and Northrop planned to change it on the production model. On the other hand, the YF-23’s weapons bay was quite large, sometimes described as being like that of a B-25. Also, it could carry two AIM-9s on the main weapons bay doors. One thing Northrop did say was that their design was not a trapeze.

We do know a bit regarding changes for the proposed EMD and production versions. There would be less modification needed than for the YF—F-22. The housings for the thrust reversers would naturally be removed. The intakes were to be revised, incorporating a half conical centerbody. The IR absorbing tiles at the exhaust always had been scheduled to be replaced with different material, but Northrop wasn’t going to spend the money for that development unless they got the contract, so the tiles were an expedient for the YFs. The aircraft was also going to have some frames added, possibly for more fuel, but primarily to allow all the length needed to mount the full forward weapons bay for two AIM-9s. I do not know if the launch rails provision on the main weapons bay doors would be retained, I suspect yes. As fortuitous fallout, the increased fineness ratio and cleanup might have made the production version even faster.

Anyway, the decision remains a topic for friendly arguments today. The fact that it wasn’t the usual competition on performance and/or cost keeps the pot simmering, and the lack of much detail on just how the YF-22 was selected adds to that. And, the fact that Northrop was ready to go months before Lockheed was but was told by USAF not to fly, even using their own money until Lockheed was ready didn’t help (Northrop got paid to keep the planes ready and to keep their team together, BTW).

Personally, I think the YF-23 was the better performing design and had the most potential, but what do I know? In any case, with two such excellent designs to work with, USAF couldn’t lose.

I agree with aaam. The YF-23 remains a mystery even to this day regarding some of its performance specs. Rumor has it that it could go mach 2.8 given the F-120 engine and supercruise above mach 2. There's just so much that we don't know about exactly how the dem/val phase went with these two to the actual AF personnel.

OTOH, do you think anybody would have wanted to see the F-32 win the JSF competition?

tacf-x wrote:

I agree with aaam. The YF-23 remains a mystery even to this day regarding some of its performance specs. Rumor has it that it could go mach 2.8 given the F-120 engine and supercruise above mach 2. There's just so much that we don't know about exactly how the dem/val phase went with these two to the actual AF personnel.

OTOH, do you think anybody would have wanted to see the F-32 win the JSF competition?

Sure

1. Boeing
2. China
3. Russia
4. Iran
5. North Korea

But, but...Boeing supports evolutionary concepts over revolutionary! Wink

In all seriousness we know almost as a fact that the F-32 would have faced more problems in development and might have been cancelled already considering the issues Boeing had getting the thing to take off vertically despite stripping and modding the inlet and the like.

Forum: Modern Military Aircraft

YF-23 question