Measurement frequency and aircraft availability: evidence from the onset of COVID-19

United States Department of Defense multi-role fighter aircraft flew 25–30% fewer flying hours than usual in April 2020, the first full month after the COVID-19 pandemic disrupted operations. More surprisingly, multi-role fighter aircraft availability rates measured by both U. S. Air Force and Department of the Navy data systems increased markedly in the initial months of COVID. The paper argues that the reported increases in availability rates are a measurement artefact arising from a reduction in sampling frequency. COVID reduced demand for aircraft, and as a result, aircraft availability was measured less frequently, resulting in a higher percentage of the fleet being recorded as being mission capable. The episode illustrates how changes in observation frequency can distort commonly-used military readiness metrics.