What happened
On June 17, 1997, at 18:23 local time, a B-55 aircraft, registration PT-LTQ, was performing a visual flight rules (VFR) flight from Alta Floresta to Campo Grande, Mato Grosso do Sul. The aircraft was carrying five people on board. During the descent toward Campo Grande International Airport, the aircraft entered a layer of fog approximately 1,000 feet above the ground.
While approaching the airport, the aircraft lost contact with the control tower. Witnesses on the ground, including sentinels at a nearby Brazilian Army ammunition depot, observed the aircraft enter the cloud layer and later emerge in a steep descent. The aircraft struck the terrain at an approximately 30-degree nose-down attitude with its wings level. The impact resulted in five fatalities and caused severe, irreparable damage to the aircraft.
The investigation
CENIPA's investigation focused on the pilot's qualifications and the operational circumstances of the flight. The investigation established that the pilot had recently obtained his Private Pilot license earlier that same year and possessed only 127 hours of total flight time, with only 54 hours experienced in multi-engine aircraft.
Crucially, the pilot's technical rating included a specific restriction prohibiting night VFR operations. Despite knowing that the arrival in Campo Grande would occur after sunset, the pilot proceeded with the flight. The investigation also noted that the aircraft's logbooks were outdated. While no mechanical failure was identified, the investigation analyzed the aircraft's flight path through the fog layer and the pilot's inability to follow tower instructions once visual references were lost.
Findings
- Inadequate Flight Planning: The pilot planned a night arrival despite lacking the necessary authorization and experience for night operations.
- Lack of Qualifications: The pilot was flying at night despite a specific restriction on his license prohibiting night VFR.
- Insufficient Experience: The pilot lacked the necessary training and experience for instrument flight, which became necessary once the aircraft entered the fog layer.
- Adverse Weather: A fog layer at 1,000 feet restricted visual contact with the ground, leading to the loss of visual references.
- Poor Judgment: The pilot's decision to fly into a night mission without proper ratings led to the loss of control within the clouds, likely resulting in an aerodynamic stall.