A viable design or not? (long post)

This post was inspired by another thread called “canceled projects,” but I didn’t want to sidetrack that discussion so I’m posting my question here.

In the “canceled projects” thread, I suggested that Lockheed’s original ATF design is an interesting “what if.” And some other posters correctly pointed out that the design had some serious problems, and that’s why Lockheed never built it.

So I decided to do some research to figure out if Lockheed’s original ATF design would have been a viable design. The research was inconclusive, so I’m seeking opinions.

Was this or was this not a viable ATF design? — viable meaning only that it could have met the basic ATF requirements, not that it was necessarily better than the real YF-22.

In October 1986, Lockheed won a contract from the USAF to build the YF-22 based on a proposed design that I will post below. However, according to several magazine articles and websites that I have found, the design had three major problems.

No. 1 — the large strake that runs from the nose to the wings created too much instability. This was solved by making the strake narrower.

No. 2 — the rotary weapons bay made the fuselage too wide, creating too much wave drag for supercruise. This was solved by replacing the rotary weapons bay with a flat one.

No. 3 — weight. This was the problem that ultimately killed the design. In June 1987, Lockheed engineers finished a weight analysis that showed the design to be 9,000 pounds over the USAF weight limit. Based on that report, in July 1987, Lockheed scrapped the design and started over.

But … Lockheed’s project leader, Sherm Mullins, has talked about how controversial that decision was within the company. Here’s a quote from him in Code One Magazine: “No one was ready to admit that our ATF was not going to be a 50,000-pound airplane.”

That seems to imply that the USAF weight limit at the time was still 50,000 pounds. IF so, then being 9,000 pounds overweight means the original Lockheed design was expected to weigh 59,000 pounds. But the USAF later changed the weight limit to 60,000 pounds, and the real YF-22 in fact weighed 58,000 pounds.

So, did Lockheed redesign the whole plane to save only 1,000 pounds? Surely not! When did the USAF change the takeoff weight limit from 50,000 to 60,000 pounds?

If anybody can clear this up for me, I would appreciate it. Why do I care? I have no idea 🙂

–Gavin.