Primary finding
Probable cause
The pilot's failure to maintain directional control after encountering a sudden change in wind direction during the landing roll.
Investigator assessment
Analysis narrative
The airline transport pilot was conducting a personal cross-country flight. The pilot reported that, during the landing roll, shortly after he had completed a three-point landing, a left quartering tailwind gust caused the tailwheel-equipped airplane to veer to the right. The pilot was unable to regain directional control before the airplane departed the right side of the runway into a drainage ditch. The right main landing gear collapsed during the runway excursion, and the airplane subsequently nosed over. The pilot reported that there were no mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot stated that, about 25 minutes before landing, he obtained the current weather conditions from the closest aviation weather station, which was located about 23 miles from the destination airport, and that the reported surface wind was from 200 degrees at 4 knots. A postaccident review of available weather data established that the surface wind was likely variable in direction at 5 knots. Although the surface wind was considered light and variable, a sudden change in wind direction shortly after touchdown likely contributed to the pilot's loss of directional control during the landing roll.
Source record
Factual narrative
On March 31, 2016, about 1145 mountain daylight time, a Cessna model 180D single-engine airplane, N180XV, was substantially damaged while landing at Shiprock Airstrip (5V5), near Shiprock, New Mexico. The airline transport pilot sustained serious injuries. The passenger was not injured. The airplane was registered to and operated by TumiAir, Inc. under the provisions of 14 Code of Federal Regulations Part 91. Day visual meteorological conditions prevailed for the personal flight that had departed from Durango-La Plata County Airport (DRO), Durango, Colorado, about 1100.The pilot reported that while enroute he obtained the current weather conditions at Four Corners Regional Airport (FMN), Farmington, New Mexico. According to the pilot, at 1120, the surface wind at FMN was 200 degrees at 4 knots. Upon reaching 5V5, the pilot completed an overflight of airport before entering a left traffic pattern for runway 20 (4,840 feet by 75 feet, asphalt). The pilot made a normal three-point landing, at about 50 miles per hour, with the wing flaps extended to 30 degrees. The pilot reported that shortly after touchdown a left quartering tailwind gust caused the airplane to veer to the right. The pilot stated that he was unable to regain directional control before the airplane departed the right side of the runway into a drainage ditch. The right main landing gear collapsed during the runway excursion and the airplane subsequently nosed over. The pilot reported that there were no mechanical failures or malfunctions with the airplane that would have precluded normal operation. The fuselage, vertical stabilizer, and rudder sustained substantial damage during the accident. The closest aviation weather station was located at Four Corners Regional Airport (FMN), Farmington, New Mexico, about 23 miles east-northeast of the accident site. At 1153, the FMN automated surface observing system reported: a variable surface wind direction at 5 knots, surface visibility 10 statute miles, clear sky, temperature 7 degrees Celsius, dew point -7 degrees Celsius, and an altimeter setting of 29.89 inches of mercury. The weather station's previous hourly report, issued at 1053, indicated that the surface wind had been light-and-variable.