History of Flight
On January 30, 2011, at approximately 0720 Pacific standard time, a Piper Twin Comanche PA-30, registration N64RJ, experienced a loss of engine power and impacted a house during landing at Big Bear City Airport (L35), Big Bear City, California. The airplane was operated by Tower General Contractors, Inc. under 14 Code of Federal Regulations Part 91. The certificated private pilot sustained serious injuries, and the airplane sustained substantial damage. The cross-country personal flight departed L35 around 0715, with a planned destination of Pacoima, California. Visual meteorological conditions prevailed, and no flight plan was filed.
The pilot reported that after takeoff and turning to left crosswind, the right engine lost power. He continued the left turn to downwind and maintained an airspeed above the single-engine control speed of 90 miles per hour. The pilot's last recollection was turning to base leg, then final approach, and seeing the runway. Subsequently, the airplane struck the roof of a house and came to rest inverted in the front yard.
A witness residing north/northeast of the airport, familiar with aircraft sounds from Big Bear Airport, reported hearing an airplane with very loud engines, noting popping and backfiring for a solid two minutes. She then heard the airplane start its takeoff on runway 26, with the sounds waning as the airplane departed. She expressed surprise that the pilot would attempt takeoff with the engine sounding as it did.
Aircraft Information
The airplane was a Piper Twin Comanche PA-30, serial number 30-1931. According to the logbooks, total airframe time at the last annual inspection (January 8, 2011) was 2,156 hours. The tachometer read 2,156.0 hours at that inspection and 2,167.4 hours at the accident scene.
The left engine was a Lycoming IO-320 C1A, serial number L-4301-55A, with total time at last annual of 2,147.0 hours and time since major overhaul of 0.0 hours. The right engine was a Lycoming IO-320 C1A, serial number L-4277-55A, also with total time 2,147.0 hours and time since major overhaul 0.0 hours. Total time on the left engine at the accident was 2,167.4 hours; the right engine had 2,165.9 hours.
Records revealed that the owner had recently overhauled both engines and was experiencing issues with the right engine running rough. On January 29, 2011, the pilot flew from Lancaster, California, to Big Bear Airport. After landing, around 1100, he called the owner of Exodus Air Service (EAS), stating the right engine was still rough. The owner advised him to find a mechanic, but none were available. The pilot sought information about magneto "P" leads. The EAS owner instructed him to ensure the leads were tight and to run the engine to check for full power, advising him not to fly if it did not produce full power. The pilot did not contact the owner again until after 1700, reporting he had not run the engine because he had gone skiing. No further communications occurred before the accident.
Wreckage and Impact Information
The accident site was located two houses southeast of the intersection of East Mountain View Boulevard and Mount Doble Drive. The airplane struck the roof of a private residence and came to rest inverted in the front yard. The site was 900 feet east of the landing threshold of runway 26, with the extended runway centerline 130 feet south of the impact point. The wreckage was recovered to Aircraft Recovery Service for examination.
Tests and Research
Investigators examined the airframe and engines at Aircraft Recovery Service in Littlerock, California, on February 2, 2011. No major mechanical anomalies were identified that would have precluded normal operations. The right magneto on the right engine was tested on a stand and appeared to function normally, but it produced noise consistent with an internal bearing anomaly. Both left and right magnetos from the right engine were sent to the manufacturer for further examination.
A Garmin GPSMAP 696 portable GPS unit was recovered from the wreckage. Despite major impact damage, data was downloaded by the National Transportation Safety Board Vehicle Recorder Lab. The GPS data showed that from 0706 PST the airplane moved from the ramp to the run-up area for runway 26. At 0712, ground speed increased as it traveled down the runway. The airplane flew a left closed pattern, reaching an altitude just over 8,000 feet (field elevation 6,752 feet), then descended on final approach at 0717. The last recorded waypoint indicated a heading of 266 degrees, ground speed 76 miles per hour, at 6,901 feet, located 1,400 feet east of the landing threshold for runway 26.
Teledyne Continental Motors (TCM) examined the magnetos at their facility in Mobile, Alabama, on March 2, 2011, under Safety Board supervision. No abnormalities were found that would have precluded normal operations.