Look Forward, Not Backward On F-35 Engines.

• Author: Vadnais, Scott

Earlier this year, Air Force Secretary Frank Kendall announced that the service would not pursue development of a new replacement engine for the F-35 stealth fighter but rather upgrade the current Pratt & Whitney-made F135 engines. That is the right decision. It is up to Congress now to close that door and move on.

The secretary, a few days after making the decision, said the move to upgrade the fighters' current engines instead of developing a new adaptive engine "was the right decision, given the constraints that we have, but [a choice] that I worry about a little bit."

Kendall shouldn't worry about his decision. It was the right call. In fact, it's in keeping with predecessors and every major aircraft the military has bought since the dawn of aviation.

Since the Wright brothers, aircraft designers and builders have consistently upgraded and improved the existing engine the aircraft was designed around as the most affordable and risk-averse option available.

In 1903, the Wright Flyer, the aircraft that made the historic first manned flight, was powered by a four-cylinder, 12-horsepower engine. By the time the Army's Signal Corps bought their first aircraft, the Wright Military Flyer in 1907, it was sporting an improved engine with an impressive 35 horsepower.

During World War II, the famed P-51 Mustang began life with a Packard-built Merlin 61 engine that cranked out 1,570 horsepower. By the time the P-51DS rolled off the production lines a couple of years later, the upgraded Merlin engine was producing 1,695 horsepower.

When the first operational F-16A was delivered in January 1979 to the 388th Tactical Fighter Wing at Hill Air Force Base, Utah, it was powered by a single Pratt & Whitney F100PW-200 turbofan, rated at 23,830 pounds thrust with afterburner. Since then, more than 4,500 Falcons have been delivered to 26 countries.

During the production of the Falcon, the program has progressively improved the engine. With Pratt & Whitney and later GE building nearly identical engines in a competition to improve reliability and performance, the jet has had five major engine upgrades with the latest version producing nearly 30,000 pounds of thrust with full afterburner.

One of the key selling points for the F-35 fighter program is that the three U.S. users and well over a dozen allies all operate advanced fighters with very similar capabilities and logistics requirements. The F135 engine powers all three U.S. variants, as well as every F-35...