What happened
On December 14, 1986, at approximately 2107 EST, a Piper PA-32R was dispatched to Philadelphia, Pennsylvania, for a passenger flight. After arriving in Philadelphia, the pilot remained on the ground to pick up four additional passengers who were scheduled to arrive around 2100 EST.
At 2007 EST, the pilot received a partial weather briefing and filed an Instrument Flight Rules (IFR) flight plan to return to Pottstown. The aircraft departed with an IFR clearance at 2145 EST and proceeded at 3,000 feet MSL, just above the cloud tops.
During arrival, the pilot was cleared for a VOR-B approach to Pottstown Municipal Airport. He reported that he could see the airport beacon from over the VOR but noted patchy ground fog. The approach continued to the missed approach point where he lost sight of the beacon. He began making a missed approach; however, when the throttle was advanced, no difference in engine sound was noted, except he recalled there may have been some "flutter in the engine." Reportedly, the aircraft continued descending and slowing until it hit trees at 440 feet MSL, approximately 1 mile northwest of the airport (airport elevation 256 feet).
The investigation
No preimpact failure was found. Temperature and dew point were 48 degrees. Ice probability chart indicated serious carb icing conditions were present. However, position of carb heat control could not be verified.
Findings
The pilot's failure to maintain engine power during a missed approach in serious carburetor icing conditions. The aircraft struck trees while descending in patchy ground fog and low visibility. The Piper PA-32R sustained substantial damage to the airframe and engine.
Safety message
Pilots should be aware of the serious risk of carburetor icing when temperature and dew point are within 10 degrees Celsius of each other, even in visual meteorological conditions. Carburetor heat should be applied as a preventive measure during critical phases of flight such as missed approaches.