CEN18LA348

The private pilot and the passenger planned to depart on a cross-country personal flight; the density altitude was about 9,500 ft mean sea level. During the pretakeoff engine run-up, the engine began running roughly. The pilot and a mechanic attempted to troubleshoot the engine issue by checking the dual magneto. According to the mechanic, the left magneto was inoperative and the P-leads were wired incorrectly; he then disconnected both magnetos' P-leads. The pilot's second and third engine run-ups appeared to produce full engine power when he adjusted the fuel mixture; however with an inoperative left magneto it is unlikely that full power was achieved. The pilot departed and was unable to maintain altitude and chose to land in a field adjacent to the airport; the airplane stalled just above the ground and then impacted the ground. During a postaccident examination of the airplane, the left magneto was removed and tested; the left magneto did not produce a spark at any terminal, and the contact points did not open. In addition, the spark plugs connected to the left magneto did not exhibit signs of recent operation, which was consistent with an inoperative magneto. The disconnected P-leads would not have affected the right magneto's ability to energize half of the spark plugs. With an inoperative left magneto and a high density altitude, the available engine power would have been reduced, and the airplane's climb performance would have been degraded. The reduction in the available engine power, combined with the high-density altitude at the time of takeoff, resulted in the airplane's inability to maintain a positive rate of climb after lifting off.

On August 23, 2018, at 1254 mountain daylight time, a Piper PA-32R-301 airplane, N2880W, experienced a partial loss of engine power after takeoff and conducted a forced landing to a field near Meadow Lake Airport (FLY), Falcon, Colorado. The private pilot and the passenger were not injured and the airplane sustained substantial damage. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the accident and no flight plan had been filed. The airplane had just departed FLY and was en route to Estherville Municipal Airport (EST), Estherville, Iowa. After the accident, the pilot stated that he had flown the airplane from EST to FLY earlier that day and planned to return to EST. During the preflight engine runup and magneto check, the engine was running rough so he taxied the airplane to a maintenance facility at FLY to troubleshoot the issue. The pilot stated that the mechanic checked the magnetos and disconnected a P-lead wire. The mechanic provided information about how the pilot should set the airplane's fuel mixture at a high elevation airport. The pilot completed another engine runup and set the fuel mixture according to the mechanic's instructions, then taxied to the runway for a "mock" takeoff roll to see if the engine was capable of producing takeoff power, which he reported was completed successfully. The pilot then taxied the airplane back to the mechanic and completed one final fuel mixture adjustment to reach full engine power at 2,700 rpm. The pilot then taxied back to the runway and began the takeoff roll; the airplane rotated for takeoff at 76 knots and 10° of flaps were extended. After climbing through 100 ft above ground level (agl), the engine experienced a loss of power and was unable to maintain altitude. The pilot stated that the stall warning horn was sounding so he lowered the nose to increase airspeed, then made a forced landing into a field straight ahead; the airplane stalled and then impacted the ground (figure 1). Figure 1 – Airplane came to rest in an open field The pilot later reported that one month before the accident, he experienced an issue with the magneto so he took the airplane to a maintenance facility where they reconnected a loose wire, then the engine operated normally. The mechanic at FLY stated that the left side magneto was inoperative and that the P-leads were wired incorrectly. He disconnected both P-leads to the dual magneto and the pilot started the engine and appeared to achieve full power. He watched the pilot complete a mock takeoff attempt, during which the airplane climbed about 6 ft agl, and then landed. The mechanic instructed the pilot to extend the flaps to 10° and set the mixture to achieve 2,700 rpm for takeoff. The pilot taxied the airplane back to the south end of the runway and departed to the north. The mechanic noted that the airplaneclimbed to at least 50 ft agl and the pitch attitude was high. He found out later that the airplane had landed in a field. The left magneto was not repaired by the mechanic, nor did the pilot request it to be repaired. Based on the temperature, dew point, barometric pressure, and field elevation, the density altitude was calculated above 9,400 ft mean sea level. Federal Aviation Administration (FAA) inspectors completed a post-recovery examination of the airplane. The recovery crew reported to the FAA inspectors that they drained about 70 gallons of fuel from the airplane and it tested negative for water contamination. During the examination the FAA noted that the fuel system was free of contaminants. They found that both P-leads were disconnected from the dual magneto and were hanging loose in the engine compartment; the magneto was removed from its mount and tested for functionally. When the drive shaft was manually actuated, the right magneto produced a spark at each terminal, but the left magneto did not produce a spark at any terminal and the contact points did not open. The bottom spark plugs for cylinder Nos. 2 and 6 were oil soaked and the No. 6 cylinder contained oil. Also, a cold engine compression check revealed that the No. 2 cylinder was low, while the rest were within normal specification. No other anomalies were noted during the examination. FAA examination photos of the spark plugs revealed that some of the electrodes were degraded and did not exhibit signs of recent operation.