History of Flight
On September 16, 2013, at about 1126 Pacific daylight time, a Cessna 180-B, registration N5112E, was substantially damaged when it ground-looped just after landing on runway 10 at Roberts Field (RDM), Redmond, Oregon. The private pilot, who owned the high-wing, tailwheel-equipped airplane, was not injured. The business flight was conducted under 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan was filed.
According to the pilot, he entered a left downwind leg for runway 10 as instructed by the air traffic control tower controller and was cleared to land. The ATIS broadcast reported wind variable at 3 knots. When the pilot reported midfield on downwind, the controller advised wind 340 degrees at 4 knots. The approach and touchdown with full flaps were normal. Just after touchdown, a wind gust lifted the left wing, and the pilot was unable to counter it. The airplane veered left, and the right wing and horizontal stabilizer contacted the runway. The airplane stopped facing back toward the approach path. The controller asked if assistance was needed; the pilot declined and taxied uneventfully to his destination.
Personnel Information
The pilot reported 1,068 total flight hours, including 520 hours in the accident airplane make and model. His most recent FAA third-class medical certificate was issued in April 2013, and his most recent flight review was completed that same month.
Aircraft Information
The Cessna 180-B (serial number not specified) was manufactured in 1958 and had accumulated about 1,914 total service hours. It was a high-wing, tailwheel configuration. The pilot reported no pre-accident mechanical failures.
Meteorological Information
The ATIS broadcast (Information Whiskey, valid 1756 Zulu) reported wind variable at 3 knots, visibility better than 5 statute miles, ceiling 5,000 feet, temperature 18°C, dew point 7°C, altimeter 29.97 inHg, and runways 10 and 22 in use. A METAR issued about 30 minutes before the accident reported wind from 330 degrees at 10 knots; another METAR about 30 minutes after reported wind from 280 degrees at 5 knots.
The Automated Surface Observation System (ASOS) at RDM recorded wind data at 1-minute intervals. Review of that data showed wind direction from the north, changing about 60 degrees in the minute surrounding the landing, with speeds between 4 and 7 knots. The ASOS gust values used a 3-second sample window, and sustained values used a 5-second window. The ASOS sensor was located about 1,000 feet beyond the runway 22 threshold, offset 700 feet southeast of that runway centerline, placing it about 5,000 feet east-southeast of the accident location on runway 10.
Airport Information
Roberts Field (RDM) is located in Redmond, Oregon. The ASOS equipment was situated in a flat, open area with no nearby features that could mask or alter sensed winds. However, numerous buildings were located about 700 feet northeast and southwest of the runway 10 landing zone. According to the Pilot's Handbook of Aeronautical Knowledge, ground topography and large buildings can break up wind flow and create gusts that change rapidly in direction and speed.
Additional Information
The Cessna Owner's Manual for the accident airplane provided minimal guidance on landing flap settings, stating that normal landings are made power off with any flap setting, and that approaches are steep with full flaps, with slips permissible if necessary. The power-off, wings-level, full-flaps stall speed was listed as 56 mph.
The Airplane Flying Handbook (FAA-H-8083-3) notes that when landing in a crosswind, a wing may rise during the after-landing roll. The upwind wing receives greater force, creating a lift differential, and as it rises, angle of attack increases, rolling the airplane downwind. If uncorrected, the downwind wing may strike the ground. The pilot should immediately apply more aileron pressure toward the high wing and maintain direction; earlier correction is more effective.