The information is shared in a statement from the Office for the Prevention and Investigation of Aircraft Accidents and Railway Accidents (GPIAAF) which has provided further information on the accident.

André Serra, 38 years old and a former Portuguese Air Force pilot, died on Friday after the Fire Boss he was piloting crashed in a vineyard at Quinta do Crasto, in Castelo Melhor, Foz Coa, Guarda district, when fighting a fire in the town of Urros – Torre de Moncorvo, district of Bragança.

At 18:45, “after informing the teams on the ground that they would carry out the last discharge of the day”, the aircraft piloted by André Serra (A01) followed by the A09 [second aircraft with whom it was paired] “made a last approach to load water, following the same path as the previous ones”.

“According to witnesses, after carrying out the load in the river, the A01, on the ascent line around the right, after having cleared the hill on the left bank of the Douro River, with an elevation of about 330 meters, started an abrupt movement. This movement was immediately followed by the pilot's action with the emergency opening of the transported water load”, says the GPIAAF.

“Evidence suggests that the engine was delivering power at the moment of impact with the ground”, reads the Information Note.

After immobilisation, the aircraft caught fire and was consumed by flames.

The crew of a Canadair aircraft that was in the same theatre of operations and following a similar trajectory over the river witnessed the crash and consequent fire of the Fire Boss piloted by André Serra.

The GPIAAF says that this Canadair plane immediately went to the place “where it made a water drop over the wreckage of the aircraft, followed by the A09 which positioned itself and proceeded in a similar way”.

The GPIAAF also mentions in the Information Note that André Serra “maintained bilateral communications” with the firefighting teams on the ground and with the Fire Boss with whom he was paired [A09], “and during the entire flight nothing was reported by the pilot about any problem or limitation of the crew or aircraft”.

According to the investigation, the pilot “was duly authorized and certified to conduct the flight” and the “aircraft was authorized to fly in accordance with the regulations in force”.