Incident Overview
During cruise flight, the pilot of a 62-year-old airplane encountered conditions where the outside air temperature gauge indicated within one degree of freezing. The aircraft then flew through a rain shower that resulted in an ice coating on the windscreen. The airplane was not equipped with an electrical system and was not IFR-equipped, leaving the pilot to rely on the limited instruments available.
Flight Difficulties
The pilot found the aircraft difficult and unstable to control by reference to instruments alone. As a result, he was unable to properly examine his sectional aeronautical map and, consequently, was uncertain about terrain clearance between his position and the airport he elected to divert to after the icing encounter.
Weather and Altitude Decisions
A 1,000-foot overcast ceiling existed in the area, within which additional icing could be expected. The pilot chose not to climb, instead maintaining his previous altitude to avoid further icing.
Collision with Terrain
When the airplane was approximately 4 miles from the airport, it flew into trees situated on the only elevated terrain within 10 miles of the runway.