What happened
While conducting a cross-country flight across northern Arizona, the pilot of the aircraft encountered adverse weather conditions consisting of clouds, rain, and moderate rime icing. While en route near Flagstaff at 11,500 feet mean sea level, the pilot notified the Albuquerque Air Route Traffic Control Center that visual flight was no longer possible due to the weather and requested an IFR clearance into Flagstaff.
During the encounter, the controller informed the pilot of rime ice reports at 13,000 feet. The pilot reported being at 12,000 feet and accumulating ice. After the pilot requested to land via the tower frequency, the controller issued a VFR transponder code and handed the flight off to the tower. Approximately two minutes later, the pilot contacted the controller again, stating he could not maintain visual contact with the ground and requested an IFR clearance into the airport. The controller instructed the pilot to climb to 11,000 feet and enter a holding pattern southeast of the FLG VOR on the 113-degree radial. This was the final communication received from the aircraft.
The wreckage was located 10 miles north of the VOR at 8,900 feet mean sea level. Impact signatures and ground scars indicated the aircraft struck mature pine trees in a near wings-level attitude during a shallow descent. A post-crash fire destroyed the cockpit, including all navigation radios and related instrumentation.
The investigation
Review of air-to-ground communication tapes revealed that transmissions from the aircraft were scratchy and of poor quality. Investigators determined that an underground fiber optic communication line had been cut on the morning of the accident, which disrupted air-to-ground and ground-to-air communications throughout northern Arizona. This disruption caused broken and garbled services and affected landline communications, necessitating a Flight Service Station to relay messages between the tower and the ARTCC.
Additionally, investigators recovered a partially burned Phoenix sectional chart dated November 1, 2001, which listed the VOR frequency as 108.2. However, on December 6, 2002, the Flagstaff VOR frequency was changed from 108.2 to 113.85.