The addition of aerial firefighting resources to wildfire suppression operations does not always result in faster fire containment. In this paper, containment times of fires with aerial suppression are compared with estimated containment times for the same fires without aerial suppression. Senior firefighting personnel who had worked on each fire estimated whether fires could have been contained within a time class if aircraft were not available. Data from 251 wildfires were analysed based on four fire-containment time classes: ≤2, 2–4, 4–8 and 8–24 h from the start of initial attack. Aircraft were perceived to reduce time to containment when firefighting conditions were more challenging owing to fuel hazard rating, weather conditions, slope, resource response times and area burning at initial attack. Comparisons of containment time with and without aircraft can be used to develop operational tools to help dispatchers decide when aircraft should be deployed to newly detected fires.