Incident Description
On 27 June 2008 at 19:00 UTC, a Tecnam P-92 Echo ultralight aircraft, registration CS-UHB, operated by Aero Clube de Pias Longas, was conducting a training flight at Pias Longas airfield in Ourém, Portugal. The flight was a training mission with an instructor and a student pilot. During the initial taxi, the instructor noticed the student had difficulty using engine power and controlling the aircraft laterally. After aligning on runway 30, the instructor decided to abort the takeoff and practice ground coordination and control instead, directing the student to taxi back to the parking area.
While exiting the runway to the parking apron, the student missed the first turnoff. Attempting to take the second connection to the apron, the student did not notice a runway marker cone that also served to delimit two taxi paths. The aircraft's propeller struck the cone, causing damage to the propeller tips.
Aircraft and Crew
The aircraft was a two-seat ultralight with a maximum takeoff mass of 350 kg. It had a valid flight certificate and insurance. The crew consisted of two: the instructor, a 43-year-old male with a Private Pilot License and instructor ratings, and the student, a 47-year-old female holding a student pilot authorization. The instructor had 925:30 total flight hours; the student had 2:30 total hours.
Aerodrome and Weather
Pias Longas runway was at 1070 feet altitude, with a gravel surface measuring 550 m by 20 m. The connection from the apron to the runway was via a single path conventionally divided into two taxiways, separated by a virtual line demarcated by a metal cone that also marked the runway boundary. On the day of the incident, the cone was displaced about 5 meters forward from its normal position toward runway 30.
Meteorological conditions at the time were clear sky, light wind from the north-northwest, and horizontal visibility affected by the sun's position low above the horizon, slightly to the left of the runway axis.
Analysis and Findings
The investigation found that the student pilot showed a marked inability to control the aircraft on the ground. Given this difficulty, it was not surprising that the student did not perceive the obstacle, especially since it was on the right side (opposite the student) and its color blended with the surrounding terrain. The instructor should have been more cautious and provided an earlier warning or corrective action to avoid the collision, perhaps assuming the obstacle had already been passed. The cone's low contrast with the ground may have affected perception, but the instructor had extensive experience operating at that airfield and should have been familiar with the markers' positions. Additionally, the sun's low angle (about 30 degrees from the runway axis) reduced visibility for the pilots.
Conclusions
The investigation concluded that the flight was authorized and planned. The aircraft was airworthy with no mechanical defects. The time of day placed the sun low and at an angle of about 30 degrees to the runway axis. The white cones contrasted poorly with the calcareous soil. The student pilot was inexperienced and had difficulty controlling the aircraft, preventing attention to small obstacles. The instructor did not perceive the obstacle in time and did not react to correct the trajectory. Both occupants were uninjured. The aircraft suffered minor damage.
Probable Cause
No single probable cause was stated; the incident was attributed to a combination of factors including lack of obstacle perception, student inexperience, instructor inattention, poor contrast, and sun glare.