Incident
Shortly after takeoff on an instrument flight rules (IFR) flight, the pilot reported that the airplane could not climb to the assigned altitude due to ice accumulation. Air traffic control cleared the pilot to return to the departure airport.
Descent and Loss of Contact
En route back, the airplane descended below the minimum descent altitude (MDA) while flying over mountainous terrain. Radio and radar contact were subsequently lost. Another airplane assisted by relaying messages between the distressed aircraft and air traffic control. The pilot was given vectors toward lower terrain. The pilot reported being in instrument meteorological conditions (IMC) at the time communication was lost.
Discovery
The aircraft was discovered eight months later. The location and condition at the time of discovery were not specified in the investigation report.
Investigation
During the investigation, no mechanical failures or malfunctions were noted. The investigation did not identify any preexisting issues with the aircraft's systems or structure.