Certified Flight Instructor (CFI) Practice Exam

What triggers an elevator trim stall?

1. Excessive nose-down trim with no power application

2. Full power applied with excessive nose-up trim

3. Full power with neutral trim settings

4. Normal power settings combined with a steep descent

The correct answer is: Full power applied with excessive nose-up trim

An elevator trim stall is primarily triggered by a scenario involving full power applications in conjunction with excessive nose-up trim. In this condition, the aircraft attempts to climb rapidly due to the power being applied; however, if the trim is set too far nose-up, it can create a situation where the aircraft may not be able to pitch down effectively to maintain controlled flight despite the thrust being generated. This mismatch in power and aerodynamic balance can lead to a stall condition where the aircraft cannot overcome the aerodynamic forces acting against it. The combination of full power with excessive nose-up trim particularly contributes to this stall because it creates an environment that exacerbates the angle of attack. When the elevator is trimmed too high (nose-up), the aircraft can reach an angle beyond its critical stall angle more easily when power is added. This situation emphasizes the importance of understanding how trim settings influence flight characteristics, particularly in power-on configurations. For optimal performance and to avoid stalls, pilots must manage trim settings in relation to the aircraft's power and the desired flight path. Thus, recognizing the potential for an elevator trim stall in this scenario helps ensure better decision-making during flight operations.