What happened
On September 22, 1946, at approximately 16:30, an Aeronca Champ (Cub) aircraft with registration CS-ADO crashed near São Pedro do Sul, Portugal. The aircraft was operated by the Escola de Aviação Civil "Viriato" in Viseu and had been rented by the pilot for a personal flight with a passenger. The pair had departed from Viseu aerodrome with the intention of visiting the thermal baths (Termas) of São Pedro do Sul to greet the passenger's girlfriend.
The pilot, flying at low altitude over the Vouga River valley, performed several passes over a road bridge. Seeking to repeat a previous successful maneuver, he attempted a tight left turn to return toward the thermal baths. However, the terrain consisted of steep terraced slopes with stone retaining walls. The pilot misjudged the aircraft's climb performance and the available space for the turn. As the aircraft approached a ridge, it failed to gain sufficient altitude despite full throttle. The nose of the aircraft struck a stone wall almost head-on. The right wing impacted the wall first, while the left wing scraped over the top of the ridge before the aircraft tumbled down the terraced slope.
The impact caused immediate structural failure and ignited a fuel fire. Witnesses reported hearing the crash and seeing the plane engulfed in flames moments later. The pilot managed to extricate himself from the wreckage but attempted desperately to rescue his passenger, who remained trapped inside. Due to the rapidly intensifying fire, bystanders had to forcibly pull the pilot away from the burning fuselage. The pilot then fled the scene in a state of shock, eventually falling from a wall and sustaining minor injuries before being apprehended by locals. The passenger was found dead inside the aircraft, having suffered severe burns.
The investigation
An inquiry was conducted by the Presidency of the Council of the Secretariat of Civil Aviation four days after the incident. Investigators visited the crash site, which was located on a steep, terraced hillside near the road connecting São Pedro do Sul to Vouzela. The aircraft was found in a partially dismantled state; investigators noted that some tubes had been sawed off to remove the deceased passenger's body.
Forensic examination of the wreckage revealed that the fuel valve and throttle were closed, while the ignition switches were in the "off" position. The engine itself showed no external signs of fracture, though it was likely damaged by the violent frontal impact. The leading edges of the wings were dented, particularly on the right side. Impact marks on a nearby stone wall confirmed that the helicopter hub and wing leading edges had struck the structure.
Witness testimony included statements from a local farmer who was the first to arrive at the scene, describing the aircraft flying low over the river before striking the wall. The pilot, who was hospitalized in Viseu, provided a statement on September 26. He admitted that he felt air disturbances that prevented him from climbing effectively but continued the flight along the river. He acknowledged attempting a turn below the ridge lines and realizing too late that the aircraft lacked the power to clear the obstacle. He stated that the passenger had cut the ignition switches just before impact.
The pilot held a valid pilot license issued on December 6, 1945. The rental of CS-ADO by the Escola Viriato was deemed compliant with regulations. The aircraft was insured against fire and collision risks.
Findings
The investigation concluded that the accident was caused by the pilot's imprecise assessment of the aircraft's performance capabilities combined with a reckless low-altitude flight intended for spectacular effect. Specifically:
- The pilot failed to account for the terrain constraints and air disturbances while attempting a tight turn at low altitude.
- The aircraft stalled or lost sufficient lift to clear the ridge, leading to a controlled flight into terrain (CFIT) against a stone wall.
- The subsequent fire was likely caused by fuel ignition following the structural breach and impact.
- The passenger's death was due to burns sustained in the post-crash fire; he had survived the initial impact but was unable to escape.
- The pilot infringed Articles 110 and 111 of the Air Navigation Regulations regarding prudent flying practices, though no specific penalties were prescribed beyond noting the occurrence in his file.
Safety action
The Escola Viriato had insured the aircraft for 90,000 Escudos. The insurance company, Companhia Tranquilidade, agreed to cover the total loss of the aircraft. It was recommended that the Escola Viriato purchase a replacement aircraft of the same type and register it under the Secretariat of Civil Aviation. No further safety recommendations were issued in this report beyond noting the regulatory infringement.