What happened
On April 5, 2016, a Cessna 206F, registration PT-IXS, was performing a cargo flight for the Special Secretariat for Indigenous Health (SESAI). The flight originated from Pouso da Águia (SWPD) in Cantá, Roraima, destined for an indigenous community near Erico Aerodrome (S/SWAQ) in Amajari, Roraima.
Upon landing at SWAQ, the pilot noted that the aircraft was not decelerating effectively. In an attempt to increase braking efficiency, the pilot retracted the flaps, but this did not achieve the desired result. As the aircraft reached the midpoint of the runway, the pilot realized the aircraft would not stop within the remaining distance. In an attempt to execute a sharp right turn to decelerate via a skid, the aircraft slid laterally off the right side of the runway approximately 360 meters past the threshold of runway 32. The aircraft collided with vegetation and became lodged in an embankment near a river. The impact caused substantial damage to the propeller, engine, and the auxiliary landing gear.
The investigation
The CENIPA investigation revealed significant discrepancies between official aeronautical information and the actual conditions at the aerodrome. While the ROTAER listed the runway as 800 meters long with a dirt surface, investigators measured the actual usable length at only 440 meters with a grass surface. Furthermore, the geographical coordinates in the ROTAER were inaccurate by 11.3 nautical miles.
The investigation also examined the pilot's decision-making process. Although the pilot had contacted the destination community regarding weather and was informed of recent rainfall, the pilot proceeded to land on the wet surface. The investigation noted that the aircraft's Pilot's Operating Handbook (POH) requires an increase in ground roll distance for wet grass runways, and FAA advisory data suggests a 60% increase in required length. The investigation found that the operator's internal planning had used a 600-meter runway estimate, which was also incorrect.
Findings
- Inaccurate aeronautical data regarding runway length, surface type, and coordinates in the ROTAER.
- Inadequate flight planning by both the pilot and the operator, failing to verify actual runway dimensions.
- Improper pilot judgment regarding the landing on a wet, grass surface and the subsequent attempt to maneuver the aircraft off the runway.
- Organizational and management failures in flight planning and oversight processes.
- Inaccurate operational planning by the company, which relied on incorrect runway length data.