Accident Overview
On April 18, 2015, at about 1100 Pacific daylight time, a Beech F33A, registration N84MD, suffered a total loss of engine power shortly after takeoff from Pierce County Airport – Thun Field (PLU) in Puyallup, Washington. The pilot, the sole occupant, was uninjured. The aircraft sustained substantial damage to the engine mounting structure. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight in visual meteorological conditions; no flight plan was filed.
Pilot and Mechanic Reports
The pilot reported that after an uneventful run-up, he took off. At about 350 feet above the ground, the engine stopped. No abnormal sounds were heard; it sounded as if the mixture had been pulled to cutoff. The pilot found a safe landing spot in a field. The aircraft rolled through the field and down an embankment before the nose wheel collapsed and the airplane came to rest nose down.
A mechanic reported that this flight was the first after an annual inspection dated April 17, 2015. On the accident morning, the pilot arrived to pick up the airplane, filled it with fuel, and taxied toward the runway. During the run-up, the engine died. The airplane was towed back to the maintenance shop, where a mechanic visually inspected and ran the engine. Nothing abnormal was found, and the mechanic suggested the pilot wait until Monday for further examination. The pilot downloaded data from the engine data monitor and took it home to review. He later returned to the airport, informing the mechanic he had found nothing abnormal. The pilot then entered the airplane and taxied to the runway. A different mechanic observed the pilot conduct several high-speed taxi tests before he took off. After departure, at about 200 feet above the ground, the engine lost power, and the airplane glided to a field.
Postaccident Examination
After the accident, an external examination was performed, and an undamaged propeller was installed. An engine run was conducted. The engine started without hesitation, but when the fuel boost pump was turned off, the engine shut down shortly thereafter. Further inspection revealed that the B-nut on the fuel pump inlet was loose. After tightening the B-nut, another engine run was attempted. The engine started and operated normally, even with the boost pump off. The engine ran for about five minutes, and the RPM was slowly increased to about 2,100 RPM. All engine gauges indicated normal operation.
Engine Data Analysis
The aircraft's engine data management system was removed and sent to the National Transportation Safety Board Recorders Laboratory. On the day of the accident, seven sessions of data were recorded. The accident sequence occurred during the seventh session. The first six sessions were recorded over a span of about 1 hour and 18 minutes. There was a break of about 1 hour and 14 minutes between the sixth and seventh sessions. Data from the seventh session showed that engine speed was increased to mid-power for approximately one minute. About two minutes later, RPM increased to 2,727, followed by 2,462 RPM six seconds later. The engine speed briefly rose to 2,628 RPM for 12 seconds before falling below 1,000 RPM.