WPR20LA009

The flight instructor and pilot receiving instruction were departing on a flight to practice instrument approaches. About 150 ft above ground level (agl), the engine “surged” then “smoothed out.” The airplane continued to climb, but the pilots elected to conduct a precautionary landing. The pilot continued the climb and made a left turn for the traffic pattern. During the turn, the engine lost total power at 380 ft agl and the instructor took control of the airplane. He landed the airplane in an empty lot; the airplane continued through a perimeter fence and impacted a semi-trailer parked along an adjacent roadway. The airplane came to rest nose down against the fence and semi-trailer, resulting in substantial damage to the left wing and forward fuselage. The postaccident airframe and engine examination revealed low fuel pressure at the fuel injectors into the cylinders. The electric fuel pump tested normally; however, low fuel pressure was noted exiting the fuel servo. The fuel servo was removed and functionally tested. The fuel flow tested slightly below manufacturer’s specifications; however, it still would have provided adequate fuel for normal operation. A teardown of the fuel servo’s metering section did not reveal any anomalies. The reason for the loss of engine power could not be determined.

On October 17, 2019, about 1800 Pacific daylight time, a Cessna 206H airplane, N11379, was substantially damaged when it was involved in an accident near Stockton, California. The flight instructor and private pilot receiving instruction sustained minor injuries. The airplane was operated as a 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor reported that the purpose of the flight was to practice instrument approaches. After a thorough preflight and engine run-up, the pilot took off from runway 29L. About 150 feet above the ground, the engine “surged” then “smoothed out.” The airplane continued to climb, but the pilots elected to conduct a precautionary landing. The pilot continued the climb and made a left turn for the traffic pattern. During the turn, the engine lost total power at 380 feet above the ground and the instructor took control of the airplane. He landed the airplane in an empty lot; the airplane continued through a perimeter fence and impacted a semi-trailer parked along an adjacent roadway. The airplane came to rest nose down against the fence and semi-trailer. The left wing and forward fuselage sustained substantial damage. Postaccident engine examination by the Federal Aviation Administration revealed no visual indications of catastrophic engine failure. The ignition leads were inspected and produced spark with normal impulse coupling operation. The spark plugs were removed and exhibited signatures consistent with a rich/low power condition. The rocker covers were removed. When the propeller was rotated, valve train continuity was established throughout, and thumb compression was established on all cylinders. The electric fuel pump was turned on and low fuel pressure was noted at fuel injectors to the cylinder heads. The fuel line between the fuel servo and the fuel distributor was removed and low fuel pressure was noted. The fuel pump was tested, and fuel pumped normally to the inlet of the fuel servo. The fuel servo was removed from the engine for an operational test and teardown. After a visual examination, it was installed onto a test stand and operated slightly below manufacturer’s specifications. The fuel servo was removed from the test stand and the fuel screen was removed; no debris was present. Disassembly of the metering section did not reveal any anomalies that would have precluded normal operation. A Lycoming representative reported that, although the fuel flow was slightly below specifications, the engine still would have had adequate fuel to operate normally.