1997 Grumman G-164B Agricultural Aircraft Accident at Águas de Moura (CS-ASB)

Overview and Investigation Background On 22 April 1997, a Grumman G-164B agricultural aircraft, registration CS-ASB, operated by AGROAR – Trabalhos Aéreos Lda., crashed shortly after takeoff from a private agricultural runway at Águas de Moura. The aircraft was destroyed, while the pilot exited the wreckage uninjured. The investigation was initially undertaken by a commission from the former GPS/INAC, but that work was not completed. In February 2008, the operator requested the final report from the GPIAA, which then appointed a responsible investigator to complete the analysis based on previously collected facts and additional documentary review. ## Flight and Accident Sequence The aircraft was conducting solid-spray agricultural work near Águas de Moura. It had been refueled with 120 liters of fuel and loaded with 650 kilograms of product. At 10:30 UTC, it took off from a private agricultural runway oriented 070°, with a northwest wind reported at 8 to 18 knots. The takeoff occurred about two-thirds along the runway, after which the aircraft began a right turn. During the turn, the pilot reported abnormal control responses and a failure to gain altitude. Engine instruments indicated 33 inches of manifold pressure and 2,250 RPM. The pilot advanced the power control fully and operated the hopper emergency door to release the load. The maneuver did not succeed, and the aircraft continued to lose altitude. The pilot did not see a medium-sized tree in the flight path; the aircraft struck the tree and crashed into a rice paddy a short distance ahead. The pilot left the aircraft under his own power, and no third-party injuries were reported. ## Aircraft, Pilot, and Environmental Information The aircraft was a single-engine biplane with a non-retractable tailwheel, equipped with a 600 hp gasoline reciprocating engine. Its maximum takeoff mass was 3,184.2 kg, and it was rated for one crew member. The pilot was a 48-year-old Portuguese male holding a Class 1 license, with 10,041:35 total flight hours. The accident site was about 15 km east of the Serra da Arrábida, near Águas de Moura, close to the agricultural runway from which the aircraft had taken off. The area contained flooded rice paddies. Meteorological information indicated a moderate northwest wind with gusts, and no precipitation. ## Damage and Survival The aircraft was destroyed. The engine separated from the fuselage, with the remaining wreckage located about five meters from the engine. The fuselage rotated after impact and came to rest opposite its direction of movement. Partial damage occurred to the rice crop. Despite the violent impact and fuel spillage, no fire started. The pilot’s survival was attributed to the seatbelts and the robustness of the cockpit, allowing him to exit uninjured.