What happened
During a low-level navigation exercise, a pilot and an instructor were flying at approximately 300 ft AGL and 80 kt, tracking a specific ground feature. While executing a steep right turn to follow the feature, the aircraft's nose dropped. The pilot noted that the turn was not tight enough to keep the aircraft over the river. In an attempt to correct this, the pilot applied significant aft control stick input instead of increasing the bank angle. This action likely induced an aerodynamic stall, causing the aircraft to descend rapidly and roll further to the right.
The investigation
The ATSB examined the sequence of events and found that the pilot failed to use the recommended recovery technique for a nose drop at low altitude, which involves increasing power rather than increasing pitch. Although the crew had successfully used the correct method earlier in the flight, the ATSB could not determine why it was not applied during this incident. The investigation also noted a period of confusion regarding aircraft control. It appears both the pilot and the instructor may have been making simultaneous control inputs, which prevented the instructor from effectively overriding the pilot's actions.
Findings
- The pilot applied and maintained inappropriate control inputs that led to an aerodynamic stall.
- A period of confusion occurred between the crew members regarding who held control of the aircraft.
- The instructor's simultaneous inputs likely hindered the effectiveness of recovery efforts.
- The instructor's use of the throttle and rudder likely prevented a nose-down impact and mitigated the severity of the crash.
- Stress during unexpected aircraft conditions can cause pilots to revert to instinctive rather than trained behaviors.