Lamego, Portugal, Aug. 28, 2025 (Lusa) - The helicopter that crashed into the River Douro in August 2024 disregarded the minimum altitude, and these deviations from the route, without operational reasons and in scenic areas, have been accepted over the years by those involved in aerial firefighting.

The conclusions are contained in the final report of the Office for the Prevention and Investigation of Accidents with Aircraft and Railway Accidents (GPIAAF), to which Lusa had access on Thursday, on the accident with the fire-fighting helicopter that took place on 30 August in Cambres, Lamego, in the district of Viseu, which killed five soldiers from the GNR/Emergency Protection and Relief Unit (UEPS).

According to the investigators, there is "the normalisation of deviations and widespread acceptance among those involved in aerial firefighting of the practice of overflying certain areas at low altitude, for no operational reason, by aircraft assigned to the DECIR - Special Device for Fighting Rural Fires", distributed throughout the country.

The investigation found "mission cancellations with deviations from the trajectories on the return to the respective bases without apparent justification" at various operational bases across the country.

"The relaxation of procedures or simply the acceptance of deviations such as flights at low altitude without a mission reason, coincidentally over areas of scenic interest, are practices observed with some frequency and which, if avoided, could have prevented the occurrence," emphasises the GPIAAF.

The agency found that, "although data is available, these deviations that have occurred over the years have not been detected or signalled by any of the entities involved in the process, namely the operators, the GNR/UEPS, the National Emergency and Civil Protection Authority (ANEPC) and the Portuguese Air Force (FAP) as the service contractor".

Regarding the accident, the GPIAAF maintains that "the pilot's decision to choose the trajectory to return to the base" in Armamar, Viseu district, after cancelling the mission to fight a fire in the municipality of Baião, Porto district, by flying over the Douro river "at high speed and low altitude, considerably increasing the risk of the flight", contributed to the crash of the AS350 - Écureuil.

The lack of supervision of this type of flight by the operator, HTA Helicópteros, as well as by the FAP and the National Civil Aviation Authority (ANAC), is also identified as a contributory factor to the accident.

Two weeks before the accident, the same pilot made two flights, in the same area, in which he again violated the minimum flight altitude.

"The flight on 15 August was recorded on video, to which the investigation had access, where a passage a few metres from the surface of the water (approximately two metres vertical distance) is observed. A similar situation [occurred] on the 16th with a mission cancelled in flight and the helicopter returning along the same route, after reversing the direction of flight," reads the report.

The pilot didn't explain the low-altitude flights.

"The pilot was unable to explain, and the investigation was unable to ascertain, the reason for the deviation from the direct route back to base on the various flights that took place, including the accident flight, following the winding Douro river valley at low altitude," the investigation states.

The GPIAAF added that the pilot's testimony, as well as information gathered from other pilots assigned to other bases in different years, "confirm the deviations with their consent to fly over specific locations, including those carried out at the request of the military of the helitransport teams (GNR/UEPS)".

"The pilot stated that, on several occasions, he agreed to requests from members of the UEPS to deviate en route to fly over specific sites outside the scope of the mission, stating that this has been an accepted practice among pilots and UEPS for several years. This information was corroborated by other pilots and members of brigades from various bases in the country," the GPIAAF said.

JGS/ADB // ADB.

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