The Aviation Safety Council （ASC）releases Final Report on investigation of a private ultra-light vehicle, model type Remos GX, while performed touch and go training, the vehicle crash on the end of runway during climb. 

On November 17, 2016, a Remos GX ultra-light vehicle, control number AJ2666, took off from an airfield in Saijia, Sandimen Township, Pingtung County to perform touch and go training. The ultra-light vehicle entered a stall at low altitude in an unexpected condition. The instructor's stall recovery maneuvers were not exactly in accordance with the corresponding procedure. Consequentially, the stall was not recovered in time, and the vehicle lost altitude and impacted the ground. The vehicle was substantial damaged and the 2 people on board sustained minor injury.  

The ASC launched investigation according to the Aviation Occurrence investigation Act after the occurrence. Investigation report was reviewed and approved by ASC's 59th Council Meeting on July 25, 2017.

Conclusion

After the ultra-light vehicle lifted off, the air speed decreased as a result of high climb rate and the maximum power had not been set. In the meantime, the stall speed was raised due to the increasing wing loading induced by the pilot's high pitch maneuver during initial climb. Thus, the safety margin between air speed and stall speed was narrowed, and the controllability and stability of the vehicle was reduced. The airflow probably started to separate from left wing and affected the lift since the crosswind was coming from the right. It caused a left bank and further raised the stall speed of the vehicle. By the time the instructor took control, he felt that the vehicle was not controllable and the wings could not be leveled. The vehicle then continued to fall in stall condition. The ultra-light vehicle entered a stall at low altitude in an unexpected condition. The instructor's stall recovery maneuvers with respect to the rudder, column, and power control were not exactly in accordance with the corresponding procedure. Consequentially, the stall was not recovered in time, and the vehicle lost altitude and impacted the ground.

Safety Recommendations

To Civil Aeronautics Administration

1. Supervise the Activity Association to ensure all airmen have adequate ability of stall recovery concept and technique, check and correct deviate speed, altitude, configuration data during take-off and landing.

To Kaixiang Aviation Activity Enhancement Association

1. Enhance all airmen to have adequate ability, concept and technique of stall recovery. Prevent vehicles from entering into the abnormal situation at low altitude and during turn. Ensure airmen conduct stall recovery procedures in accordance with Standard Operating Procedures.
2. Enhance all airmen of the Activity Association to check and correct speed, altitude, and configuration. Special notice and wider safety margin should be given to high risk phase during take-off and landing.
3. Follow the Activity Guide procedures to maintain and preserve occurrence site and evidences for investigation.

The full Final Report is in Chinese only and available for download at ASC website: www.asc.gov.tw

Contact：Sherry Liu, Engineer
Tel: 89127388-330
Email: Sherry@asc.gov.tw