At least nine active duty US Marine Corps Aviation squadrons failed to accurately report the present state of their squadron’s aircraft readiness in late 2017 and early 2018 due to confusion about what data should be recorded.

The errors occurred because the Marine Corps readiness reporting guidance is unclear and was interpreted differently by the squadron commanders, according to a report by the Inspector General for the Department of Defence published on 8 August.

The inaccuracies could leave the service unexpectedly short of aircraft during training or operations, which could make it more difficult to accomplish missions and may increase risk for marines.

According to the Inspector General, the Marine Corps readiness guidance is unclear at what time aircraft readiness is to be counted, silent on how squadron commanders should report the number of mission-capable aircraft, and unclear on how squadron commanders are to report their mission essential tasks as having enough supporting personnel and equipment.

Many of the errors were due to slight variations in aircraft readiness counting processes. For example, different squadron commanders counted their available and ready aircraft over different time periods, some using a prior 30-day average, some using a specific point in time and others using a 7-day forecast.

The Inspector General recommended a number of fixes, including sticking to a single aircraft management software program, as well as creating clear definitions and processes.

In response to the recommendations, the Marine Corps agreed to revise the aircraft count definitions and processes, as well as use the recommended software.