One hour into the flight, the pilot requested an IFR clearance. The pilot made several incorrect radio calls to Denver Center, saying he was at 5,500 feet when he was actually at 9,500 feet, and that he was on the 320-degree radial from the Medicine Bow VOR when he was actually on the 140-degree radial.
The pilot turned left to intercept the Medicine Bow 252-degree radial. ATC then asked him to turn right to rejoin Victor 6 (the 252-degree radial). The front-seat passenger was holding the chart, and noticed that the flight was crossing I-80, but Victor 6 was north of I-80 on the chart. When he questioned the pilot, the pilot didn't respond, but appeared "busy with the airplane's avionics." The Cessna traveled about 7.5 more miles in a southwest direction before hitting Elk Mountain 9.5 miles south of the Victor 6 Airway.
The NTSB determined that the pilot did not follow proper procedures for tracking a VOR radial while on an IFR flight plan in IMC. The instrument-rated private pilot had 339 hours of experience, with 6.6 in actual instrument conditions. He completed an instrument proficiency check two months before the accident, in a different airplane, and a mountain checkout six weeks later, in the accident airplane.
The accident airplane was equipped with a horizontal situation indicator (HSI)-type VOR receiver. It could not be determined how much experience or training the pilot had with an HSI. Because no mechanical failures were found, the pilot's confusion while talking with Denver Center indicated that he may have been struggling to read the HSI.
For more information on single-pilot IFR operations, take ASF's Single-Pilot IFR online course and read the Single-Pilot IFR Safety Advisor.
Kristen Hummel manages the GA accident database for the AOPA Air Safety Foundation. She holds a commercial pilot certificate with multiengine and instrument ratings.