Incident Overview
On June 15, 2014, at approximately 1110 Pacific daylight time, a Piper 28-180, registration N4931L, experienced a partial loss of engine power after takeoff from Gansner Field Airport (2O1) in Quincy, California. The aircraft was operated under 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The certified flight instructor and three passengers were uninjured, and the airplane sustained substantial damage.
Pilot's Account
The pilot reported that he took off with 10 degrees of flaps. During the initial climb, he retracted the flaps, and the airplane began to lose altitude. He extended the flaps again, and the airplane continued to climb, but when he retracted them a second time, the airplane descended. Realizing the airplane would not climb, the pilot elected to make a precautionary landing onto a nearby field. During final approach, the stabilator impacted a fence post before the airplane landed uneventfully.
Postaccident Examination
A Federal Aviation Administration inspector conducted a postaccident examination. Compression was present on all four cylinders. The intake system showed no restrictions or damaged components. The carburetor float bowl was removed, and the fuel inside appeared uncontaminated. A light shone into the forward exhaust pipe indicated it was partially blocked; the aft exhaust pipe was also partially blocked. Both mufflers were removed, revealing that the muffler baffling had separated from its mount and covered the exhaust port outlet.
Maintenance History
Review of the engine maintenance logbook records showed that the most recent annual inspection was completed on May 15, 2014, at an airframe total time of 4,016.55 hours. The pilot reported that, at the time of the accident, the airplane had accumulated about 3 hours of operation since the annual inspection. The front muffler time in service could not be determined; the aft muffler time in service was 1,359 hours. During the annual inspection, an exterior inspection of the muffler system was performed, but the exhaust system inspection recommended by Piper was not carried out.
Manufacturer's Recommendations
The Piper Cherokee Service Manual states: "…a very thorough inspection of the entire exhaust system including exhaust heater shroud assembly, muffler and muffler baffles, stacks, and all exhaust connections and welds must be accomplished at each 100-hour inspection. The possibility of exhaust system failure increases with use. It is recommended that the system be checked more carefully as the number of hours increase, therefore inspection at the 700 hour period, that the exhaust system has been in use would be more critical than ones in the 100 hour period. The system should also be checked carefully before winter operation when the cabin heat will be in use. NOTE: Piper recommends that all PA-28 airplanes be fitted with a new muffler at or near the 1,000 hour period of which the muffler has been used."