What happened
On June 2, 2011, at approximately 15:00, a Reims F172N was performing a commercial banner towing flight at Teuge Airport (EHTE). The mission involved picking up a large advertising net, measuring roughly 70 square meters, which had been laid out on the grass by ground personnel.
The pilot approached the pickup point on a circuit on the north side of the airfield. During the procedure, the aircraft successfully engaged the tow rope. However, as the aircraft climbed above a treeline, it experienced a significant roll to the right, likely due to a crosswind. In an attempt to correct this, the pilot utilized the ailerons, which increased drag and caused the airspeed to drop significantly. The aircraft's speed fell to approximately 40 knots CAS, well below the prescribed climb speed of 55 knots CAS. This loss of speed led to an aerodynamic stall. The aircraft subsequently lost control, entered a heavy roll to the left, and impacted the ground at a steep angle. The pilot sustained fatal injuries and passed away the following day.
The investigation
The Dutch Safety Board (OVV) conducted a technical examination of the wreckage and the towing equipment. The investigation found no mechanical failures in the engine, the airframe, or the towing mechanism. The aircraft had sufficient fuel for the mission, and the weight and center of gravity were within legal limits.
Investigators utilized video footage of the accident to reconstruct the aircraft's flight path and airspeed. The analysis confirmed that the pilot's use of ailerons to correct the yawing motion contributed to the rapid deceleration. Additionally, the investigation examined the pilot's safety equipment and adherence to the VNLO handbook procedures. It was noted that while the pilot was properly trained according to industry standards, the specific execution of the pickup procedure deviated from those established safety guidelines.
Findings
- The primary cause of the accident was the aircraft entering a stall due to insufficient airspeed during the climb following the net pickup.
- The pilot's decision to use ailerons to correct a yawing motion increased aerodynamic drag, causing the airspeed to drop to 40 knots CAS, which was below the required 55 knots CAS.
- The pilot was not wearing the shoulder harness at the time of the impact. This failure to secure the upper body allowed the pilot's head to strike the instrument panel during the sudden deceleration, which caused the fatal head trauma.
Safety action
- The investigation noted that previously announced government actions regarding commercial banner towing safety had not been implemented.
- It was observed that the pilot's adherence to the VNLO handbook's specific speed and safety protocols was lacking during this specific operation, despite being properly trained under those guidelines.