What happened
On February 5, 2022, at approximately 11:40 UTC, a Piper PA-25-235, registration PR-BUB, was performing agricultural spraying operations near the Base Seragri landing strip in Luiz Alves, Santa Catarina. The aircraft was engaged in a reversal maneuver, commonly known as a "balloon" turn, to reposition itself for a new spray swath.
During the execution of left and right turns, the aircraft experienced a loss of lift. The pilot reported that while maintaining an indicated airspeed of 75 mph and a 30-degree bank angle, the aircraft began to lose altitude. In an attempt to recover altitude, the pilot applied maximum engine power and extended the flaps to the intermediate position. However, these actions failed to arrest the descent. The aircraft subsequently struck trees and impacted the ground approximately 225 meters before reaching the intended application area. The aircraft sustained substantial damage, while the pilot sustained minor injuries.
The investigation
CENIPA investigators confirmed that the pilot was properly licensed and rated for agricultural operations, with a valid medical certificate. The aircraft was airworthy, with a valid Certificate of Airworthiness, and was operating within its weight and balance limits. Engine testing following the accident revealed that the powerplant was functioning normally and producing adequate power at the time of the occurrence.
Meteorological data indicated favorable flying conditions with no significant weather formations present. The investigation focused on the aerodynamic behavior of the aircraft during the maneuver. Investigators noted that the manufacturer's manual recommends using flaps only to maintain a steep descent angle and warns against their use in other flight phases due to the secondary effect of increased drag. Analysis of the wreckage, including the distribution of debris and damage to the right wing spar, suggested the aircraft entered a stall and followed a descending spiral trajectory prior to impact.