ERA21LA019

The commercial pilot reported that, after takeoff, the engine lost partial power. With limited runway remaining, the pilot decided to make a forced landing during which the airplane departed the runway and traveled about 200 ft into the grass. During the runway excursion the airplane sustained substantial damage to the empennage. A postaccident engine test run revealed that the right magneto exhibited a drop off of 245 rpm, which exceeded the airplane manufacturer’s ground check guidance. Furthermore, the timing of the right magneto could not be determined because the contact points would not open far enough. The left magneto operated normally and had proper timing. It is likely that the anomaly observed with the right magneto resulted in a partial loss of engine power, the pilot’s decision to abort the takeoff, and the subsequent runway excursion.

On October 11, 2020, about 0810 eastern daylight time, a Piper PA-32-260, N3595W, was substantially damaged when it was involved in an accident at Dekalb-Peachtree Airport (PDK), Atlanta, Georgia. The pilot and two passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, he landed at PDK on the day before the accident and requested that the airplane fuel tanks be topped off. On the day of the accident, the pilot performed a preflight inspection with no anomalies noted. He taxied the airplane to runway 21R, advanced the throttle to full power for takeoff, and noted that “the RPMs were producing full power, temps [temperatures] and pressures where in range and that airspeed was alive and increasing as normal.” The pilot stated that, after takeoff, the airplane continued to accelerate normally until it was about 150 to 200 ft above ground level. At that time, the pilot noted an “abrupt reduction in engine noise.” The pilot decided to make a forced landing, and the airplane touched down on the runway. The airplane then departed the end of the runway and traveled about 200 ft into the grass. The airplane sustained substantial damage to the empennage. A postaccident engine run was performed. When the magnetos were checked, the right magneto drop off was 245 rpm. The oil filter was examined, and small ferrous and nonferrous particles were noted. A cylinder compression check was performed, and low compression was noted in cylinders Nos. 2 and 4. The magneto timing was checked, and the left magneto was timed to 25° from top dead center. The right magneto contact points would not open far enough to check the timing. The engine controls were examined, and no anomalies were noted. Furthermore, the mechanic performing the engine rebuilding work after the accident noted that four cylinders “showed signs of extreme heat.” The cylinder bores had grooves, and the interior marks “appeared fresh” with “no signs of smoothing” from operation. In addition, multiple “substantial” intake system leaks were noted. According to the Sky Ranch Engineering Manual, high cylinder temperature could be a result of an improperly timed engine. According to the Piper PA-32-260 owner’s handbook, during a ground check, a “drop off on either magneto should not exceed 125 RPM.”