Colorado Aviation Accidents & Incidents

On August 16, 1998, approximately 1630 mountain daylight time, a Cessna 170, N2574V, was substantially damaged following an intentional ground loop initiated by the pilot at Boulder Municipal Airport, Boulder, Colorado. The private pilot and his two passengers received minor injuries. The airplane was being operated by the pilot under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the personal cross-country flight which originated from Ogallala, Nebraska, approximately 2 hours before the accident. A VFR flight plan had been filed.

The pilot reported that as he approached Boulder Municipal Airport (elevation 5,288 feet, density altitude 7,807 feet) for a full stop landing, he heard the pilot of another airplane which was landing on runway 8 report that he had a tail wind during his landing. The pilot said that he "noticed the wind sock on the east end of the runway was standing straight out in a direction that appeared to be 180 degrees." The pilot landed on runway 26, but reported having difficulty keeping N2574V aligned with the centerline. He said, "I immediately determined to execute a go around. I had trimmed nose up for landing so I was attempting to get the nose down but was also buffeted by very turbulent winds [coming] over the hangers to the south." The pilot said that he believed it was safer to perform a ground loop then to go in the lake at the west end of the runway. He said, "I didn't feel at the time I stood any chance of gaining airspeed to execute a climb."

One witness reported that immediately after the accident, they noticed that the wind was coming from the northeast. The winds at Jefferson County Airport (BJC), which is 9 nm southeast of Boulder Municipal Airport, were 180 degrees and 13 knots at 1549. At 1655, the winds at BJC were 150 degrees and 11 knots gusting to 20 knots. The pilot's intentional ground loop and his inadequate compensation for the wind condition. A contributng factor was crosswinds.