January 22, 2016
Newer Aircraft, Bigger Bills
In the USAF, mission-capable rates are not a matter of age or scale efficiencies.
By James Hasik
I thought that the graphic artist’s straightforward table could be usefully made into someting more analytically revealing, so I built a bubble chart of fleet sizes atop a scatter plot of fleet readiness versus average aircraft age. In the embeded figure, the bubbles and the attached numbers represent how many of each aircraft type the USAF has in its fleet. (To match the numbers to the aircraft type, see Schogol’s article.) The chart further displays the average age of that fleet on the horizontal axis, and the mission-capable rate throughout 2015 on the vertical axis. In this analysis, I thus take fleet age and fleet size as independent variables that could logically affect the dependent variable of fleet mission-capable rate. That seems reasonable.
The figure, however, doesn’t seem to suggest that either age or quantity leads to readiness. Those 76 B-52Hs have a readiness rate of 72 percent, but they average 52 years old. Conversely, the far newer F-22s and CV-22s are much less available, at 67 and 56 percent. The overall statistics actually say less: no regression—linear, logarithmic, polynomial, power, or exponential—of readiness on these two factors produces a correlation coefficient above two percent. The interrelationship of the two dependent factors also doesn’t seem meaningful: regressing on the log of the product (call that airframe-years) produces roughly the same low coefficient.
That lack of results doesn’t mean that fleet age and size are unimportant. It’s entirely possible that the USAF is throwing maintainers and money at those Predators, and similarly ready Reapers, on which Central Command so heavily relies. But at a certain point, all that effort hits limits in the art of the possible. The swing-wing, supersonic B-1B is just a much more mechanically complicated aircraft than the B-52H. Fairly, those -52s aren’t really 52 years old, as their wings, engines, tails, fuselages, and landing gear have all been replaced or rebuilt. But just as fundamentally, the older plane’s maintainability “comes from the original engineering and simplistic design.” As Schogol quoted Lieutenant Colonel Todd Andre, the division chief for aircraft maintenance at Bomber (er, Global Strike) Command, “most of the subsystems are based on 1970s technology.” In contrast to the F-22A, we know for sure that they don’t have millions of lines of code to troubleshoot and delicate composite skins to patch.
So when you hear that the USAF’s fleet is older than it has been in decades, don’t immediately lament its material condition. Excepting the drones from General Atomics, it's the newer aircraft that are harder to maintain. As I heard an USAF general say some months ago, the maintenance costs of those stealt aircraft are eating his lunch. I’m not sure that’s progress, but I know that it may soon be deleterious to the Air Force’s finances.
James Hasík is a senior fellow at the Brent Scowcroft Center on International Security.