While the Curtiss P-40 is one of the iconic aircraft of W.W. II,
utterly forgotten is its more streamlined cousin, the YP-40SW.
It all began in Germany in the 1930s.
Alexander Lippisch is one of the giants of aeronautics, world-famous for his futuristic designs.
Completely lost to history is his precursor in swept-wing technology, one Professor Albert Lipschitz.
Seeing all the upheaval going on, Prof. Lipschitz left Germany after his favorite
Imbiss was taken over by the local Strength Through Joy committee and the cuisine suffered accordingly. He hoped his radical ideas might take off in the United States.
While the good Professor had some success with his swept-wing designs back home, going from garage-built proof-of-concept to a practical aircraft was daunting.
Finally, exigencies caused by the war in Europe provided Prof. Lipschitz with the funding and resources he needed.
He also found a partner in the National Advisory Council on Aeronautics who were keen on cutting-edge technology. A Curtiss P-40 was provided for modification after wind-tunnel tests showed this to be the best currently mass-produced airplane to serve as a test-bed.
By the summer of 1944, the P-40 (s/n 413762) had been modified with swept wings and horizontal tail surfaces. Even the original rudder was altered by slightly changing the curve to compliment the sweep of the other flying surfaces.
The new aircraft, officially designed the YP-40SW (Y for off-budget expenditure, SW for Swept Wing), certainly had a most striking appearance even if the original wing concept was marred somewhat by the classic Curtiss P-40 landing gear knuckle.
While Prof. Lipschitz approached flight testing in a detached, almost clinical manner, inside he was brimming with child-like excitement at finally seeing his swept-wing concept in the form of a modern aircraft, backed by the U.S. government no less!
Unfortunately, while the swept-wings were quite unique, the aircraft was still just a P-40. The modifications improved performance only marginally and other straight-wing fighters already in production such as the P-51, utterly outclassed it.
Still, Prof. Lipschitz's NACA YP-40SW would have a career as a chase plane on the Airacomet X program which was an ill-advised attempt at improving the P-59 that finally terminated in 1948. This made the YP-40SW the last P-40 in U.S. government service even though by then it was made obsolete by the dawning Jet Age.
Seeing things end like that was hard for the good Professor and he died of what some said was a broken heart right about the time the YP-40SW was broken up for scrap. Little remains of either Professor Lipschitz or his radical NACA test-bed and few know that he was one of the early pioneers of swept-wing technology.
Brian da Basher