The aircraft “Daily Utilization Rate” is a very important measure affecting an airline’s potential profitability. Airlines want their aircraft flying in the air as much as possible to produce maximum revenue per aircraft.

Of course the daily utilization rate will vary from airline to airline slightly, and from long-haul international wide-bodies compared compared with short haul narrow bodies.

But to answer your question, American Airlines is a good example. Their daily aircraft utilization rate was 9.81 hours for wide bodies, and 9.86 hours for large narrow bodies per day in 2014, which is fairly normal within the industry. [Note: These hours are “block hours” measured from gate to gate including taxi time and holding time on the ground. Subtract about one hour from these times for actual time airborne.]

Having closely monitored the daily utilization rates for a number of airlines over the years but not so much recently, the rate has ranged approximately from a low of 8 hours to a high of slightly over 11 hours per day. (Source: Airline Data Project)

Other factors will also affect the daily utilization rate like both scheduled and unscheduled maintenance. Aircraft maintenance checks like a “C” check will keep an aircraft out of service for a day or two; a major “D” check will keep the aircraft out of service for 1–2 weeks.

Another factor with short-hauls is that the aircraft may spend an hour sitting at a gate between flights deplaning and boarding passengers, perhaps 5–7 times a day. Then there is marketing. There is little passenger demand for a flight departing at 2 AM, so the aircraft will not depart then but will sit until sunrise.