What happened
On May 17, 2007, a Cessna 152, registration CS-DAZ, was conducting a VFR navigation flight departing from São Jacinto (LPAV). The flight was intended to visit the residences of friends and family, flying at low altitudes over various locations including Vila Nova de Gaia and Póvoa de Varzim.
As the aircraft approached the area of Nespereira, near Guimarães, the pilot performed several low-altitude passes. During a left-hand turn, the aircraft descended below 100 feet and struck two medium-voltage electrical cables. The impact deformed the propeller, caused the engine to stop, and tore the tip off the left wing. The collision also caused an electrical discharge and severed the cables.
Despite the loss of engine power, the pilot maintained control of the aircraft and performed an emergency landing in an unprepared, grassy field near residential buildings. During the landing roll, the aircraft overturned onto its engine and propeller. The two occupants sustained minor injuries and were treated at a local hospital.
The investigation
The GPIAAF investigation examined the flight path, the aircraft's condition, and the pilot's performance. Radar data from the Lisbon FIS indicated that the aircraft had been flying at extremely low altitudes, including 0 feet altitude at certain points along the coastline, and below 500 feet AGL in several sectors. The investigation also reviewed the physical evidence at the crash site, noting that the grey color of the cables against the dark green vegetation likely hindered visibility. The investigation confirmed that the aircraft was airworthy and the pilot was properly licensed.
Findings
- The aircraft was flying significantly below the minimum safety altitudes established by ICAO Annex 2, specifically over populated areas where a minimum of 1,000 feet AGL was required.
- The pilot's attention was likely diverted by observing people on the ground, leading to a failure in altitude control during a low-altitude maneuver.
- The collision with electrical cables was the primary cause of the accident, leading to the loss of propeller traction and subsequent engine failure.
- The violation of Air Rules regarding minimum safe altitudes acted as a contributing factor.