McDonnell Vought A/F-X

[stever_sl]

While poking around through bins of stuff collected in my 42-year aerospace career this morning, I uncovered a couple of stickers from the weird A/F-X competition where McDonnell Douglas had 2 separate teams working on 2 competing proposals with different sets of teammates. We were teamed with Vought on the one I was involved with. It was in the days when "Integrated Product Teams" were all the rage with management. We had IPTs for everything on that program, with comical results in some cases. I recall that there was an Outer Wing Panel IPT and an Inboard Wing Panel IPT with the separation line being at the wingfold (for the USN version). Usually there would be a single Wing Team but IPT was going to show us how to be more efficient and innovative and other buzzwords. Instead, each IPT did their own structural design independently, with the goal of carrying the local loads with the lightest possible structure. And when they were done, they'd come up with an outer wing having a different number of spars than the inner wing, so the wingfold ribs had no easy way to handle the carry-through bending and torsion loads. THAT took some fancy sorting-out.

But the feature that caused the worst headaches involved something that's usually utterly benign, the inlet ducts. I've gone into this elsewhere but to recap, our top program manager was embracing yet another management fad called Management By Walking Around. He was making a tour of the design area and happened to notice that one of the most junior people had sketched a layout with the inlets on top of the fuselage instead of at the wing roots. He instantly seized on this as a way to make our design stand out visually from those that the competing teams would probably be producing. So that became our unchangeable design centerpiece. Only later did we realize that those inlets created all kinds of unsolvable practical problems, which again I've covered in some detail elsewhere. Suffice it to say that even if those problems had somehow been overcome, what resulted was a remarkably ugly airplane, so much so that when the whole program mercifully collapsed, our "clean sheet" A/F-X (as opposed to the "Son of A-12" that the other McDonnell Douglas-led team was working on) never made it into the real world in the form of articles or even photos. Various people have expressed curiosity about it, here and in other groups, but very little was available.

So when I found those stickers this morning, they made me take one more look with more creative search terms. And lo and behold, there it was, right here in this forum! So if anyone is interested, here it is! ("A Design Is Emerging" may be the ultimate in wishful thinking, out of all of the projects I supported in my career... )

 

[stever_sl]

I can also share something that shows how we working-level folks felt about the design that was emerging. Everything involving aesthetics was sacrificed to low signatures, so a modification of a then-current cartoon was put together. Here's the original cartoon. The little thing that the designer's nose is being rubbed into was replaced by one of the A/F-X drawings, and the word "designer" was replaced by "L.O. weenie."

 

[H_K]

I don't find it ugly actually! If only those dorsal inlets could have worked out. What if the engines and dorsal inlets had been more widely separated, more like the YF-23 (but with overwing instead of underwing inlets), would that have helped?

Perhaps remind us of the links to your other posts so we can read again about why it wouldn't have worked?

Edit: Ah found a post of yours on dorsal inlets!

https://www.secretprojects.co.uk/threads/possible-configuration-of-the-boeing-f-a-xx.50919/post-877384

As time went on, we (the rank and file) realized that with the inlet literally right behind the cockpit, it would be impossible to safely do ground run-ups with the canopy (canopies, actually) open due to the risk of the flow field pulling "things" out of the cockpit and straight into the engines. That wasn't all: There was nowhere to put the air refueling probe (for the USN/ROW version) or UARRSI port (for USAF) that was outside of that flow field. During air refueling there's always a little puff of vaporized fuel on separation from the tanker, coming from the short section between the shutoff valves on the tanker and receiving aircraft. The amount of fuel vapor needed to cause ignition and detonation in the bypass ducts of the engines - well, tests at China Lake had already produced data on that for a wide variety of high-bypass turbofan engines, and so we knew that the vapor puff was something that our engines couldn't tolerate. So clearly the "overhead inlets" as we called them were just not going to work.

 

[stever_sl]

I don't find it ugly actually! If only those dorsal inlets could have worked out. What if the engines and dorsal inlets had been more widely separated, more like the YF-23 (but with overwing instead of underwing inlets), would that have helped?

Perhaps remind us of the links to your other posts so we can read again about why it wouldn't have worked?

Edit: Ah found a post of yours on dorsal inlets!

https://www.secretprojects.co.uk/threads/possible-configuration-of-the-boeing-f-a-xx.50919/post-877384

That's the one! I wonder now, with the benefit of hindsight, whether the USAF variant might have been OK with the UARRSI on the centerline behind the inlets so that any little squirt of vapors couldn't be pulled in. Maybe it actually was there for all I know now. But the USN version had to have its probe somewhere within the field of view of the aircrew, so it was going to have to be up front and high. And there was still the problem of having the canopies open with the engines running. There were 2 separate canopies, 1 for each seat. One was hinged on the side, the other at the front or rear, I can't recall which. So with both open it was going to look odd anyway.
About my "ugly" comment, it doesn't show up well in the illustration but the wingtips were absolutely square, up and down, not rounded or faired at all. And I don't think there was much inboard-to-outboard thickness taper either. It gave the impression that somebody had just cut the shape out on a bandsaw.

It was good to work with LTV though. Very early in my career I'd been on the small team of engineers supporting the last of the F-8 Crusaders, the RF-8G photo-recce variant (plus one DF-8L drone controller) and I absolutely loved that airplane. So LTV was OK in my book!

 

[FighterJock]

The image looks a bit like a stealthed up Hornet which would not be too far considering that McDonnell Douglas were the main designers of the F/A-18

 

[Manuducati]

Thanks for sharing your personal hindsight!
This image (plus a scale model and pictures of the wind tunnel model) can be found in the "Navy AX and A/F-X projects" thread.
Look especially from page 8. Post in thread 'Navy AX and A/F-X projects' https://www.secretprojects.co.uk/threads/navy-ax-and-a-f-x-projects.2150/post-663700

 

[Hydroman]

Top mounted inlets, look at that wing and penetrating/bombing from altitude and not on the deck. Funny, if the USN didn't have their heads in theirs asses, they could have had our Northrop ATA.