What happened
On July 18, 2005, at 13:20 local time, a Cessna 150G, registration EC-IRK, was performing a solo instructional flight originating from León Airport. The flight plan involved a visual flight to Valladolid Airport for refueling, followed by a return to León. The pilot, a student with approximately 23 flight hours, was operating the aircraft alone.
The flight proceeded without incident until the landing phase at León Airport. During the approach, the pilot encountered a large dust cloud, which was being generated by ongoing earthmoving activities related to airport expansion works. The pilot reported that this dust cloud caused a loss of visual references and led to an excessive approach speed. Upon touchdown, the aircraft bounced on the runway. Following the bounce, the pilot applied aileron inputs that contributed to a loss of directional control, causing the aircraft to veer off the right side of the runway. The aircraft came to a stop 574 meters from the threshold of runway 23. The pilot was uninjured, but the aircraft sustained significant damage to the propeller hub and the nose gear.
The investigation
The CIAIAC examined the aircraft's systems and the environmental conditions at the time of the accident. While the pilot initially attributed the high approach speed to a total failure of the airspeed indicator (anemometer) that had allegedly occurred since the departure from Valladolid, investigators performed a functional ground test of the Pitot-static system.
Visual inspections of the Pitot tube revealed no external damage or obstructions. Functional testing using specialized equipment demonstrated that the airspeed indicator was operating correctly and that there were no leaks in the Pitot system. Although a mechanical stop was found that prevented the needle from reaching zero, the system's performance during simulated airspeed changes was accurate. Investigators noted that because of the significant time elapsed between the accident and the testing, they could not definitively rule out a temporary malfunction, though no evidence of such a failure was found during the inspection.
Findings
- The primary cause of the loss of directional control was the incorrect execution of the landing maneuver.
- The presence of a dust cloud from nearby construction works hindered the pilot's visibility and prevented an accurate assessment of the aircraft's speed using external visual references.
- The pilot's use of aileron controls following the bounce likely contributed to the loss of directional stability.
- There was no evidence found during the investigation to confirm a failure of the airspeed indicator.