June 23, 2007:
One of the most successful military
jet engine designs, the F100, is
expected to be in use for over sixty years before it is retired. Over 7,000 of
the Pratt & Whitney F100 engines have been manufactured since 1974. It's
the engine used in the F-15 and F-16 fighter. Sixteen feet long and with a
maximum diameter of nearly four feet, the two ton engine produces up to 29,000
pounds of thrust. The main competition for the F100 is the GE F110, which is
similar in size and performance. The U.S. Air Force got two similar designs
into production so the two manufacturers would constantly be competing to
provide the best engine at the lowest price. This saved the air force several
billion dollars.
During World War II, the aircraft engine was
recognized as the single most critical component of an aircraft. It was then
that the adage, "get the best engine and build an aircraft around it" came into
being. This continued after the war. In the 1970s, the designers of the F-15
and F-16 came up with a theoretical engine for these two new designs, and the
engine manufacturers had a hard time delivering so much power in such a small
package. Currently, these engines cost about five million dollars each, and
consume several times that in maintenance and spare parts, over a useful live
of several thousand hours of use. Each F-16, for example, will go through 2-3
engines over its lifetime (20 or so years). One of the key factors in U.S. Air
Force air superiority over the past sixty years has been the quality of the jet
engines, and the willingness to use those engines a lot, and provide quality
maintenance. Not very sexy, but pilots can't survive, much less become aces, if
their engines are not reliable.