Event Summary
A pilot received a preflight weather briefing that included warnings of occasional moderate mixed and rime icing, as well as isolated severe mixed and clear icing along the intended route. During the flight, the pilot encountered icing conditions and ice accretion on the aircraft. The manifold pressure began to decrease, and the pilot was unable to maintain altitude. Subsequently, a forced landing was executed in a residential area, where the airplane struck a house and a car.
Pilot Report
The pilot reported that at 5,000 feet, he expected to be above the freezing level due to a temperature inversion. This expectation held until reaching the Philadelphia area, where light mixed icing was encountered on the leading edges. Thereafter, the manifold pressure dropped to 21 inches, and altitude loss began. Although the pilot anticipated an increase in manifold pressure during descent, none occurred. At about 2,000 feet, the pilot determined that he could not reach a nearby airport and declared a mayday while maintaining 95 knots.
Postaccident Examination
A postaccident examination of the airplane included a functional check of the engine in a test cell. The engine operated rich below 1,800 RPM, and takeoff power was achieved. No mechanical discrepancies were noted with the airplane.