Report Finds Navy Super Hornet Fighter Jets Aging Worse Than Predecessors

A new report published by the Congressional Budget Office assess the availability rates of the Department of the Navy's FA-18 fleet. (Image: Boeing)

Introduced in the mid-to-late 1990s, the Department of the Navy’s (DON’s) F/A-18E/F Super Hornet is a multirole, fixed-wing aircraft capable of attacking other planes in the air or targets on the ground. Super Hornets are significantly larger and more capable than their predecessors, the F/A-18C/D Hornets introduced in the mid-1980s and still in use. (A modest number of F/A-18A/B Hornets, which were introduced in the early 1980s, also remain in operation.)

The fleet of F/A-18s is currently the mainstay of naval shipborne aviation. The Congressional Budget Office periodically analyzes two complementary aspects of aircraft fleet performance: what share of time aircraft could have been flown on training or operational missions in a given period (availability) and the hours of flight that actually occurred (use).

Many factors affect aircraft use, including aircraft availability, military needs, and external elements such as weather and budgets. If DON does not need to fly its aircraft as much, it may choose to accept a lower availability level so as to reduce its maintenance costs.

A January 2022 report by CBO found that the greater decline in availability rates of DON aircraft relative to Air Force aircraft was driven by a steep decline in the availability of DON’s fighters and attack aircraft, particularly the F/A18 C/D Hornets.1 This report examines how Super Hornet availability rates and flying hours compare with those of older F/A-18s and other fighter and attack aircraft.

Assessing availability and use in tandem can be informative because one measure can affect the other. An aircraft with a low availability rate may be unable to fly as much as DON might wish. In the other direction, if a fleet’s aircraft are flown more hours, they could end up in maintenance awaiting replacement parts and thus be unavailable for additional flight.

This report describes aircraft availability and use patterns but does not assess whether those patterns have been sufficient to meet DON’s operational needs. Aircraft availability rates are, at least to an extent, a choice that depends on the amount of funding provided for aircraft maintenance. By investing in, for instance, greater supplies of spare parts, a military service can increase aircraft availability rates.

Likewise, a military service can choose whether and how much to fly an available aircraft, realizing that flying aircraft more increases costs, both for fuel and maintenance. The age-based figures in this report are best-fit curves, showing smoothed portrayals of the observed relationships between the ages of aircraft and their availability and usage rates.

As with past reports, CBO measures fleet availability rates by dividing the number of hours that aircraft are both mission capable and in the possession of operational squadrons by the total number of aircraft hours for the entire fleet. (A mission-capable aircraft can perform at least one of its primary training or operational missions.)

The measure that CBO uses typically produces lower availability rates than the measure used by the Department of Defense (DoD). That is because CBO’s measure has a larger denominator that includes aircraft in a depot getting maintenance or in storage. In contrast, DoD divides the number of hours that aircraft are both mission capable and in the possession of operational squadrons by the total number of aircraft in the possession of those squadrons.