In our contribution, we evaluated a plan and goal recognition (PGR) system to enable adaptive pilot assistance in dynamic helicopter missions. In highly dynamic environments, pre-planned mission sequences often become obsolete when the mission environment changes. To provide efficient support, the assistant system requires an understanding of the pilot’s current intent. We implemented a PGR system based on hierarchical task networks (HTN) to recognize tactical goals and plans from pilot behavior and situational data. We performed an experimental evaluation in our mission and cockpit simulation environment with 10 professionally trained helicopter pilots. The system successfully inferred the plan and tactical goals, aligning with data labeled by the participants. Recognized intentions can serve as triggers for adaptive interventions, enabling implicit communication and real-time assistance to adaptively support the pilot in executing the mission.