Aircraft engines have always been expensive, and at the leading edge of performance—military engines even more so. As the performances increased, so has the cost, with the engines increasing in complexity, part count and in the sophistication of the metallurgy and materials used in their construction. Performance is an order of magnitude better than at the dawn of the jet age. But when adjusted for inflation, are modern power plants more expensive?
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For all 119 years of the history of aviation, all powered flight has had one thing in common: expensive engines.
The result was speeds in excess of 400 miles per hour in high-performance aircraft like this P-51 Mustang. When there’s a war on, nobody talks about cost, but it’s an interesting thing to analyze compared to the price of modern engines for similar applications.
The Packard Merlin V12 piston engine that powered the Mustang cost approximately $25,000 per unit, a substantial sum for 1944. Using the Bureau of Labor Statistics’ inflation calculator tool, this equates to $426,000 in 2022. Remember, that’s just for the engine.
But piston engines were superseded by jets. Let’s take a look at a direct lineage for those military engines.
This Lockheed P-80, the first practical U.S. military jet aircraft, was powered by an Allison J-33 turbojet. That engine was relatively simple, with the centrifugal flow compressor and single turbine, but was durable and reliable enough to stay in production until the late 1950s in training aircraft. It generated just under 5,000 pounds of thrust for most applications, and in 1949 it cost $20,000—less than the famously complex World War II Packard Merlin piston engine and representing approximately $250,000 in today’s money.
From a value for money perspective, that is significant: higher performance for a lot less money.
Ten years later, aircraft speeds were up to Mach 2, and this aircraft is the poster child for high-performance in that era: the Lockheed F-104 Starfighter. Its General Electric J-79 turbojet was significantly more complex than early engines, with multiple stages and variable pitch stators, and an afterburner. It was manufactured for decades in numerous variants, but an early model like the Dash Three variant used in a Starfighter would cost about $625,000 in 1960. That’s equivalent to about $6,300,000 today.
Why the big jump? Much higher complexity, better metallurgy, much more thrust and over 15,000 pounds.
Now take a look at this aircraft, the McDonnell Douglas F-15. It first flew in 1972, powered by the Pratt & Whitney F-100 turbofan. Enhanced versions of this engine still fly today, and while unit cost is increasingly difficult to estimate because of the complex program accounting for jet engine development, a good ballpark estimate of the 1991 cost of a 229-F-100 turbofan is three and half million dollars, which is roughly seven and a half million dollars today.
Today’s latest and most complex engine, the F-135-PW-600 for the short takeoff, vertical landing F-35-B, is reported by defence – aerospace.com as costing 21 million dollars per engine. So, a first-generation jet engine in today’s dollars cost approximately a quarter of a million dollars. And today, it’s over 20 million.
Lifecycle costs are a different matter, and early jet engines had a time between overhauls that could be measured in tens of hours. But the fact is, technical innovations like vertical takeoff, super cruise and combined cycle engines have made military power plants staggeringly expensive. And that’s one reason why aircraft procurement today is measured in tens and hundreds, rather than thousands.