<p><?tk 2?>A variable cycle engine provides the capability to operate the same engine at high thrust requirements with high specific thrust and at low thrust requirements at low specific fuel consumption. The variation of bypass ratio and thereby mass flow rate can also be utilized to reduce the spillage and aftbody drag of the aircraft. This characteristic of the variable cycle engine potentially increases the mission endurance and makes it a candidate for sixth generation fighter aircraft. The disadvantages of a variable cycle engine are the more complex mechanical layout and control structure as well as higher engine mass. Thus, the engine selection for a future fighter aircraft requires carefully executed studies. For the multi-disciplinary study presented here, extensive data on spillage drag and especially aftbody drag was generated. So, the drag values as well as the fuel consumption during the mission of a generic fighter aircraft can be calculated. The major boundary condition of this study is to leave the airframe unchanged in order to focus on the comparison of the engines and have no further influence from the airframe. The results show that the bypass ratio of the variable cycle engine can be scheduled to reduce both the spillage and aftbody drag compared to the conventional engine. When the engine mass remains the same, this leads to a small benefit in mission endurance. With an investigated engine mass penalty of 200&#xa0;kg on the other hand, the mission endurance of the aircraft with variable cycle engines is lower than the one of the conventionally powered aircraft.</p>