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Flightline Friday: The Best Book on the ATF Program and YF-23, Ever February 24, 2017

Posted by Tantumblogo in awesomeness, Flightline Friday, foolishness, fun, history, reading, sickness, technology.

I did a Flightline Friday about a year and a half ago discussing, among other things, the YF-23 Advanced Tactical Fighter prototype produced by Northrop.  The Advanced Tactical Fighter (ATF) program was initiated in the 1980s by the USAF to produce not just an F-15 replacement, but a fighter that could finally and decisively sweep the skies over Central Europe during an all-out conflict with the Soviet Union.  It was designed to be the most comprehensively advanced and dominant air combat aircraft ever produced.

The program evolved over the course of the 80s.  From many disparate concepts from a whole lot of companies – very few of which exist anymore – the program was eventually narrowed down to a competition between a team led by Northrop (with McDonnell Douglas) and Lockheed (with General Dynamics and Boeing).  Northrop produced the YF-23 (and this was ALL Northrop, McAir had almost nothing to do except some cockpit layout and providing the landing gear from an F-15), and Lockheed the YF-22 (here the situation was entirely different, GD contributed TONS to the Lockheed design and may have saved their bacon.  Lockheed massively redesigned their aircraft proposal in 1987-8, requesting 6 additional months from USAF to do so, because the original concept had so many problems).

At any rate, history shows, for reasons that are still inexplicable to some, that USAF preferred the ugly, block-like YF-22 to the graceful YF-23. Both aircraft had advantages over the other – the YF-23 was faster, in most respects stealthier and had superior supersonic maneuverability, while the YF-22 was better in the close-in, subsonic fight and carried substantially more missiles internally.

Even though the aircraft were designed nearly 30 years ago, much data on them has remained classified.  Particularly classified has been concrete data on the production aircraft proposed by Northrop for the F-23.  The actual production F-23 would have differed significantly from the YF-23, for a variety of reasons, though not nearly so much as the F-22 has wound up differing from the YF-22 (of course, USAF had a great deal to do with that, and details on Lockheed’s original engineering and manufacturing development version of the YF-22 – basically their vision of the production aircraft – have been even harder to find than those of the F-23).

Also somewhat limited has been extensive detail on the numerous other submissions made over the early phase of the ATF program from companies like Grumman, North American (Rockwell), McDonnell Douglas, Boeing, etc.

Well all that has ended, as former Northrop Chief Test Pilot and YF-23 lead pilot Paul Metz has now, in conjunction with Steve Ginter, produced THE seminal book on not only the F-23 but the entire ATF program. And this thing is an absolute gem. I was up way past 1 last night because I could not put the book down.

Just a few of the highlights:

  • Loads of never-before seen photos of ATF submittals and YF-23
  • Incredibly detailed construction drawings of YF-23
  • Extensive sections of the F-23 EMD submittal (upon which the USAF judged the winner of the competition – again, this was the manufacturer’s plan for final production design, maintenance, operations, etc) are repeated
  • Incredibly detailed construction drawings of the F-23 EMD design.  There has been one of these outted before but Metz adds several more
  • Detailed history of YF-23 development including key players involved, like Yu Ping Liu, who designed the aircraft’s stealth characteristics
  • Detailed history of Northrop’s internal design progression towards a stealthy air combat fighter over the years 1971-1986. The YF-23 design was basically fixed by late 1985 (!!)
  • An unprecedented amount of material on the Naval ATF version.  During the late 80s, it was planned that the Navy would buy a navalized version of the ATF winner to replace the F-14.  The end of the Cold War killed that idea.

The book is brand new (hit shelves Christmas last year) and a bit high (~$38).  It’s not real long but it is jam packed with information.  One of the things I have noted from those involved in the YF-23 program is the fact that it was a labor of love, the people working on it really loved each other and the amazing product.  That really shows through in this book, even though Metz eventually went to work for Lockheed and became chief test pilot on the rival F-22 team (after Lockheed won the competition), I get the sense from this book that his heart was always with the F-23.  As well it should have been.  It is still, as of this writing, conceptually the most advanced and capable aircraft ever produced.

A quick addendum: I noted in the post linked in the top some deficiencies with the YF-23 design that may have helped inform USAF’s decision to prefer the F-22 concept.  Because we knew so little about the F-23 EMD proposal, it was assumed some of those problematic features would have remained the same. No more.  The F-23 EMD corrected both the engine fan blade viewing problem and, for the most part, the shortfall of internal carriage of AMRAAMs compared to the F-22 (still would have been one short, but that’s a pretty small difference).  The F-23 EMD was MUCH different from what people thought based on the limited info that was out there.  If anything, it made the aircraft even more attractive.  If only they could have gotten rid of that canopy brace……


If you have anything more than a passing interest in the F-23 or F-22, get this book.




1. The Lord's Blog - February 24, 2017

Reblogged this on Jean'sBistro2010's Blog.

2. Brian E. Breslin - February 24, 2017

Tantum, I hope you do not mind me sending you a link to Caroline Glick’s column from today. She touches on some of the very things you have in past Friday Flightlines. I have found myself rarely disagreeing with her nor with you.

3. Brian E. Breslin - February 24, 2017
Tantumblogo - February 24, 2017

Very interesting. Thanks for that.

4. Richard Malcolm - February 24, 2017

So what’s your theory on why the USAF went with the YF-22 instead, Tantum?

Tantumblogo - February 24, 2017

Man I had a long comment and lost it. I’ll try to repeat on Monday. I think the book helps put some of the theories to rest. F-23 was not expected to be significantly more expensive to develop than F-22. At least Northrop thought not. But Northrop had gone overbudget on B-2 and some think USAF did not trust them much at that point, which was a reason to go with Lockheed.

More significantly, though, Lockheed realized more than Northrop did that USAF was (and still is, to some extent) fixated on the low and “slow” fight that didn’t go so well in Vietnam. They wanted ultimate performance in the turn from M0.5 – 0.85 or so and from 15-25k ft. Just like Vietnam. Now, in reality, the F-23 was virtually as maneuverable as the F-22 in all areas but instantaneous pitch and AoA change. Those huge tailerons were massively effective, practically as good as the 2-D thrust vector on the Raptor, Metz says. However, Lockheed actually demonstrated extremes of performance in the flight phase, whereas Northrop played it safer and just went with simulations. So, Lockheed went out to Mach 2+, Northrop only M1.8 (though the YF120 powered F-23, in particular, was capable of much, much, MUCH more). Lockheed pulled 9Gs, Northrop only about 6.5. Lockheed went to 60 degrees AoA, Northrop only demonstrated 25 (which was the requirement). The thinking is that Lockheed really wowed the pilot community with their performance and even though Northrop simulations showed their bird could do at least as well (and much better in some areas), no one physically saw it, flew it, and that was a big factor.

So I think it was a fighter pilot mafia “do we really believe these guys” kinda thing, USAF being unhappy w/ Northrop, and some concerns over cost/program management. That sounds like pretty weak tea given -23s other advantages, but then again this was the Bush Administration that killed F-14D in favor of F-18E/F among many other things. Cost was huge. Showmanship may have entered into it. The book makes clear, though, that things that looked like differences in the flyoff phase would not have been factors during production, such as some stealth “mistakes” (all identified with fixes already designed in), imbalance in internal missile carriage (it would have been 8 for Raptor and 7 for F-23), and canopy brace interference with visibility (Raptor viz today is far, far worse than an F-15 or 16) were really non-factors. That doesn’t leave us with much to go on, other than USAF expected Northrop to go way over budget. Maybe they would have. And maybe we’d only have 80 flying F-23s today vice 180 Raptors due to cost. Hard to say. I still think it was a mistake, and set a really bad precedent going forward.

Richard Malcolm - February 24, 2017

OK. Some of that’s interesting to hear.

The fighter mafia remains powerful – one wonders just how long they can resist what looks like the coming age of the UAV/drone.

Then again: perhaps these are just the foibles that will be hard to avoid when you haven’t had to fight an air war against a peer power, or at least peer aircraft piloted by peer pilots (Vietnam really being the closest we’ve had to that since Korea, and obviously that was still a limited war). War has a way of shaking out the mistakes and bad actors, the hard way. We’ve been fortunate not to have to fight one. But perhaps that comes with its inevitable costs. Consider just how bad a shape so much of our air services – to say nothing of the army! – were in when each of the last world wars rolled around (though we were rapidly catching up when Pearl Harbor struck).

I don’t know how to evaluate this one. Too much information not available. For now, I am inclined to think that the Super Tomcat was the more egregious cut by Cheney. I think we have enough information to make that call now. But boy, was he determined to wipe it out.

Tantumblogo - February 24, 2017

Don’t disagree regarding Super Tomcat. I’d much rather the V-22 cut had stuck and the F-14D/Super Tomcat could have remained. And the A-6F, too. Naval aviation would be in much better shape. Few people know how many dire shortcomings the Super Hornet has, though the biggest, range, has been ameliorated by there always being Air Force tankers around. Should it ever develop that there aren’t, like near China?, watch out. People would learn very quickly and to their dismay what lousy shape naval aviation is in.

See this?


Richard Malcolm - February 25, 2017

Oh yes, the A-6….:sigh:

We’ve gotten away with it all so far. But it takes such a long lead time to develop a new system.

5. Chris Weber - February 26, 2017

The F-23’s weapons bay was bigger than the F-22’s. This would have been an advantage, considering the redesign work needed on the missiles so that they can fit in the F-22.

YF-23 Weapons Bay

Richard Malcolm - February 26, 2017

I think the F-22 is a very good fighter, overall.

It seems there’s a case now now that the F-23 might have been a little better (a pity we couldn’t have built some of both).

But that makes the F-22 decision more justifiable than going with the Super Hornet over the Super Tomcat. The gap there seems to be much, much wider.

Tantumblogo - February 27, 2017

I may try to compile a list of all pluses and minuses between the two this Friday. I missed some other concerns USAF had on the YF-23 – those engine troughs at the rear with metallic-ceramic tiles were a concern, for instance. Would the tiny cooling holes needed to keep the tiles viable survive fouling with engine emissions? USAF was pretty concerned about maintaining these on a flight line.

But OTOH, Metz claims YF-23 was MUCH stealthier and, even more, this stealth was not as dependent on the really hard to maintain coatings that the F-22 relies on. Apparently the shape of the aircraft requires much less RAM on the surface. And they worked out a novel design for removable panels that did not require taping over with RAM every single time they were accessed, which has been a huge maintenance issue on the -22. Maintaining LO has been the #1 source of expense in maintaining F-22 and is the reason its MCR is still pretty low.

Complex story. I think it comes down to cost, USAF thought F-22 would be cheaper (even if that may not have been the reality), and also Northrop management’s inexplicable decision to go real conservative on the flight demonstration part of the program. They had an incredible design that was frankly way ahead of its time – but was eminently manufacturable – but didn’t realize that the DEM/VAL phase really WAS a flyoff which plane could go higher, faster, turn more G, fire missiles, etc – instead of the mere confirmation of simulations USAF said it was. Lockheed went balls out in DEM/VAL while Northrop chose to play it much safer. That left many in TAC with the impression the YF-23 wasn’t really ready for prime time and the YF-22 far more advanced, developmentally, when in reality it was probably more the opposite.

Tantumblogo - February 27, 2017

I should add, I don’t think the F-22 crap, or that the decision was a disastrous one. Given the collapse of the FSU and the end of the Cold War, USAF was right to be concerned about cost as a paramount factor. I just think history has shown the decision made in ’91 may have been more questionable than it appeared at the time. Back then, most people saw it as something of a toss up. Military analyst Stuart Slade summed it up best over 15 years ago, Northrop produced the plane USAF asked for, Lockheed perhaps the one it really wanted.

Tantumblogo - February 27, 2017

Well the EMD plans shown in the book – and some of these have been at the increasingly defunct yf-23.net in the past, show a configuration with 5 AIM-120Cs (same version as F-22) and 2 AIM-9Ms. Don’t know where someone got the idea that the F-22 bays were smaller, the main bay is much deeper and makes it much easier installing missiles. YF-23 may have been better for bombs, however.

6. David - February 27, 2017

While I have only met a few military test pilots, the ones I met who became astronauts were generally down to earth regular guys. Pilots with attitudes like in the movies usually ended up dead, or weren’t eligible for test pilot school due to lack of a technical degree.

I never met Wally Schirra (CAPT, USN), but I did read his autobiography Schirra’s Space. He has a chapter of the time he spent at Pax River. Being a test pilot takes quite a bit of diligence and attention. Schirra mentioned that there were some planes that should never have left the drawing board.

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