Chair Force Engineer

Sunday, September 10, 2006

More on "The Northrop Curse"

I was thinking some more about "The Northrop Curse" mentioned on the astronautix.com blog. Some more discussion is warranted on Northrop's big flyoff defeats.

B-35 vs. B-36
The Flying Wing which had so enthralled Jack Northrop was finally realized in the XB-35. Unfortunately, the XB-35 had a few strikes against it from the start. Its weapons bay was too small for first-generation atomic bombs to fit in. The gearbox which turned the contra-rotating propellers was too complex. The prop-powered bomber would have been too slow to evade enemy jet fighters.

History shows that the B-36 was chosen for production instead and its speed was later boosted with the addition of four jet engines. Undaunted, Jack Northrop pressed on with the YB-49, which replaced the four piston engines of the XB-35 with eight jets and the necessary vertical stabilizers (required after losing the stabilizing influence of the props.) The fuel-thirsty J35's of that era boosted the Flying Wing's speed, at the expense of its range. By this time, the Air Force had relegated the B-49 to the reconnaissance role, before cancelling the program outright in 1950. The case for the flying wing was certainly harmed by the Glen Edwards crash (which was caused by an ill-conceived, low-altitude stall test, where the aircraft's structural limits were exceeded in the recovery attempt.)

A-9 vs. A-10
I don't know enough about the A-9 vs. A-10 flyoff, but it's clear that the Air Force obtained a classic, rugged anti-tank aircraft in the A-10. The Warthog does have numerous advantages in the way it was laid out; the engine faces are shielded from small arms fire by the wing trailing edge, and twin rudders provide redundancy. The A-9 had vulnerable, low-mounted engines located in the wing root, and it only had a single tail. Still, Northrop engineers should feel vindicated that the A-9's basic layout was duplicated in the Su-25 Frogfoot.

YF-16 vs. YF-17
By most accounts, this flyoff was no contest. The YF-16 which was selected for the Air Force had superior speed, range and maneuverability relative to the Northrop-built YF-17. The caveat here is that the YF-17, designed without the then-unproven fly-by-wire control, was a more stable bombing platform. The twin-engine layout of the YF-17 was also a plus for the air-to-ground mission. The YF-16 was supposed to be a day fighter with very limited ground attack capabilities. Instead, the F-16's ground attack capabilities have grown exponentially more important over the aircraft's life. The F-16 eventually became a low-end replacement for the venerable F-4 Phantom II. If Air Force planners had foreseen this change in requirements, perhaps the YF-17 would have been selected instead.

F-16 vs. F-20
Northrop's F-20 was the ultimate evolution of the F-5 series. It also took the same guiding philosophy of the YF-16: a lightweight, highly maneuverable fighter that would win a dogfight without being saddled with ground support duties. The F-20 was an 80% solution, coming close to the F-16 in many aspects of performance while still being affordable. The F-20's case was hurt by two fatal crashes and an absence of orders from the US Air Force, which would have reassured foreign customers. Northrop wanted to sell F-20's as aggressor aircraft to the US Navy, but General Dynamics sold the F-16N at a price that was too good to be true. The last straw was the relaxing of arms import regulations which prevented many countries (especially Taiwan) from buying the F-16. While the F-20 was a good bet for countries that couldn't get F-16's, there was just no beating the real thing once it became available.