I don't need to know, but I hope we have a top secret stealth fighter jet that, years from now, will be declassified and part of the same discussions as the Blackbird. Here's the primary evidence—what there is of it—that the F-19 exists and remains classified:
1. Since 1962, fighter planes have been designated by consecutive numbers, beginning with the F-1 Fury. F-13 was never assigned due to superstition. After the F/A-18, the next announced aircraft was the F-20.
2. The venerable Jane's All the World's Aircraft listed a Lockheed RF-19 in a 1987 reference book—"erroneously."
3. There's an F-19A Ghostrider in Tom Clancy's 1986 novel Red Storm Rising.
Here are some additional "facts" and "photos" culled from the Internet.
Next up, supposed Northrop catalog copy from the mid-’80s. Did Northrop used to sell classified fighters by catalog? Let's go with it.
There's also this ad Northrop supposedly had to pull in order to preserve the secret.
And this Google Earth shot of disassembled F-19s at an airplane boneyard in Arizona: