In order to enhance the decision making process, all air operation team players need to be alert and share information or concerns just in time. Earlier studies apply the mnemonic DESIDE (Detect, Estimate, Set, Identify, Do, Evaluate) to teach pilots to optimize their individual flight safety decision making process. In this paper, DESIDE will be applied by a team of three to test the effectiveness of the tactical decision making tool for teams. For that purpose, eight teams of Falcon 4 gamers were asked to perform an identical set of tactical missions in simulators. Each team consisted of two fighter jet pilots and one supporting Unmanned Aerial System (UAS) operator. In the control condition, a team received a short classical Crew Resource Management (CRM) training, similar in content to the CRM training received in the Royal Netherlands Air Force (RNLAF). In the experimental condition a team received a short training in the use of the DESIDE decision making tool (Murray, 1997). Over the course of five tactical missions, the subjects learned to apply DESIDE. In each debrief, the team was given feedback on the decision making process (according to the instruction received) and mission outcome by a former F-16 Weapons Instructor. The quality of the decision process and outcome was monitored and compared between the teams. The NOTECHS (NOn TEChnical Skills) behavioral marker system in combination with the RNLAF rating scheme was used to evaluate decision making. The results indicate that the DESIDE tool for decision making is effective for teams in a military context. It does generate improved decision making process quality in teams of F-16s and a UAS, performing air operation missions.