Incident Overview
On the afternoon of August 1, 1998, a Cessna 172C with registration CS-AKF experienced an accident while taxiing at the Cascais Municipal Aerodrome in Tires, Portugal. The aircraft was operated by ATA, Aerocondor Transportes Aéreos, Lda., for a commercial aerial work flight designated as ATA ARD481. The mission involved traffic surveillance on the 25 de Abril Bridge. Both occupants on board were unharmed.
Operational Context and Weather Conditions
The pilot reported to the operator at 15:00 UTC and received a briefing indicating winds from the northeast at 30 knots with gusts up to 40 knots. The aircraft was fueled and inspected before the engine was started on apron "Alfa." The air traffic control tower confirmed wind conditions of 20 degrees, 30 knots, with gusts reaching 40 knots. These conditions created a significant crosswind component relative to Runway 35.
Sequence of Events
The pilot initiated taxiing toward the intersection of apron Bravo and the runway, intending to turn left to align with Runway 35. The pilot reported that the tailwind effect made it difficult to control the aircraft, as the wind force exceeded the effectiveness of the brakes. Unable to maintain control during the initial maneuver, the pilot requested instructions to taxi along the runway, make a right turn, and then re-enter the main taxiway for the Runway 35 holding position.
During this second attempt, the pilot again found the aircraft difficult to manage due to the tailwind effect. Deciding to abort the takeoff preparation, the pilot attempted to return to the apron by turning left and taxiing along Runway 17 with a tailwind. During this maneuver, the flaps inadvertently extended to the full position. This caused the nose gear to lift off the ground, resulting in the main wheels lifting as well. The aircraft immediately dropped back onto the pavement, causing the rotating propeller to strike the ground. The aircraft came to a stop across the runway near the shoulder.
Damage and Investigation Findings
The accident resulted in damage to the wingtips and the outer third of the leading edges of both wings, with deformations on the upper surfaces. The propeller blades were deformed with tips bent outward, and the nose gear showed signs of misalignment. No fire occurred, and there was no damage to third parties.
The investigation noted that the approved flight manual for the Cessna 172C did not specify limit values for wind during taxiing or takeoff, providing only guidance on configuration for strong winds. Similarly, the operator's manual lacked specific quantitative limits for wind in various operational phases, deferring to the manufacturer's manual. Consequently, the decision to proceed with operations under these conditions relied on the pilot's judgment.