To reduce emissions of air traffic, future aircraft will install hybrid-electric propulsion systems. We require the load conditions over the time in service, to design these aircraft. In this paper, we propose a mission profile for a regional aircraft with a hybrid-electric propulsion system. We focused on regional aircraft, which are in service in Ireland and the United Kingdom (UK). The reference aircraft ATR\,72-600 is a turboprop aircraft with a capacity of 70 passengers. To propose a mission profile, we have analyzed more than 6000 flights of four different aircraft of the same type. Input data is provided by online databases, which collect flight data. We are able to show that the maximum available power is needed for about 52 seconds during take-off and climb phase of the flight. The median flight time is 59 minutes and 30 seconds. The average required power is 53\,\% of the maximum power. The average traveled distance is 407\,km, which is less than one third of the aircraft's maximum reach. These findings are needed for calculating the lifetime of drivetrain components of a hybrid or all electric aircraft. In our further work, we will design an electric machine for regional aircraft. ... mehrThis mission profile will be used to design different power train components.