Document
OAS-25 (4/18)
Department of the Interior Aviation
SAFETY ALERT
No. DOI SA 25-01 November 15, 2024 Page 1 of 2 Subject: Top Cub Rear Flight Control Stick Installation Area of Concern: Flight Controls Distribution: All Top Cub Activities Discussion: A recent mishap revealed the possibility of improperly installing the aft seat control stick in the Top Cub aircraft. Improper installation of the rear control stick will limit both control stick’s (front and aft) range of travel resulting in limited aircraft control. The improper installation results in the stick being installed 180 degrees (backwards) from it proper direction of installation.
The designed bend in the control stick, which allows for maximum range of travel when installed correctly, restricts the full range of control when installed incorrectly (backward). The range of travel is further limited in the forward direction when the front pilot seat is positioned at its maximum aft setting.
In this situation, the front pilot’s seatback obstructs forward travel.
As a result, the following recommendations are provided to prevent this situation from occurring and to ensure flight safety. All Top Cub Pilots should: 1. Review the AFM Supplements Section 9.15 concerning proper rear stick and cover installation.
2. Ensure all aft pilot control sticks are labeled with a label stating “this side forward” facing toward the front pilot to improve the pilot’s ability to identify the correct orientation of control stick installation.
3. Ensure preflight activities include checking proper aft pilot control stick installation or stowage.
4. Ensure both preflight and before takeoff checklists requiring flight control checks are performed correctly IAW the AFM to verify maximum range of travel.
No. DOI SA 25-01 Date: November 15, 2024 Page 2 of 2 Figure 2 shows the aft control stick installed incorrectly.
Figure 1 shows the control stick installed correctly allowing free range of travel.
Figure 4 Figure 3 and Figure 4 shows the incorrectly installed aft control stick contacting the front pilot’s seatback.
/s/ Keith Raley Keith Raley Chief, Aviation Safety, Training, Program Evaluations and Quality Management