WPR15LA167

Factual narrative

On April 18, 2015 about 1100 Pacific daylight time, a Beech F33A, N84MD, experienced a total loss of engine power shortly after takeoff from Pierce County Airport – Thun Field (PLU) in Puyallup, Washington. The pilot (sole occupant) sustained no injuries, and the airplane sustained substantial damage to the engine mounting structure. The airplane was registered to, and operated by, the pilot under provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, and no flight plan was filed. The pilot reported that after an uneventful run-up he took off from the runway. About 350 feet above the ground the engine stopped. There were no abnormal sounds, but instead it sounded as if the mixture had been pulled to cut off. The pilot found a safe place to land and landed in a field. The airplane rolled in the field and down an embankment before the nose wheel collapsed and the airplane came to rest nose down. A mechanic reported that this was the first flight after an annual inspection dated April 17, 2015. The morning of the accident, the pilot came to pick up the airplane; he filled it with fuel and taxied toward the runway. The pilot was conducting a run-up when the engine died. The airplane was towed back to the maintenance shop and a mechanic visually inspected, and ran, the engine. Since nothing was found the mechanic suggested the pilot wait until Monday to have it further examined. The pilot downloaded the data from the airplane's engine data monitor and took it home to examine. Later that day the pilot returned to the airport and he informed the mechanic he found nothing abnormal on the data. The pilot got back into the airplane and taxied it to the runway. A different mechanic observed the pilot conduct a few high speed taxi tests before he took off. After the takeoff, about 200 feet above the ground, the engine lost power and the airplane glided to a field. After a postaccident external examination and the installation of an undamaged propeller, an engine run was performed. The engine started without hesitation, however, when the fuel boost pump was turned off the engine shut down shortly thereafter. Upon further examination, the B-nut to the fuel pump inlet was noted to be loose. The fuel line B-nut was tightened and another engine run was attempted. The engine started and it operated normally, even after the boost pump was turned off. The engine was run for about five minutes and the engine RPM was slowly increased to about 2,100 RPM. All engine gauges indicated normal operation. The airplane's engine data management system was removed from the airframe and sent to the National Transportation Safety Board Recorders Laboratory. On the day of the accident there were seven sessions of data recorded. The accident sequence occurred during the seventh session. The first six sessions occurred during a time span of about 1 hour and 18 minutes. There was an about 1 hour and 14 minutes break between the sixth and seventh sessions. The data revealed that during the seventh session, the engine speed was increased to mid power for approximately one minute. About 2 minutes later the engine RPM was increased to 2,727 RPM followed by 2,462 RPM, 6 seconds later. The engine speed briefly increased to 2,628 for 12 seconds before falling below 1,000 RPM. The private pilot was conducting the airplane's first flight after an annual inspection. On the morning of the accident, the pilot picked up the airplane and conducted a run-up, during which the engine lost power. The airplane was towed back to the maintenance shop, and a mechanic recommended that the pilot wait until a more detailed examination could be completed. The pilot downloaded the data from the airplane's engine data monitor and took it home to examine. After returning to the airport later that day, the pilot reported to the mechanic that he did not observe anything abnormal in the data, and he got back in the airplane to depart for the accident flight. The pilot reported that, about 350 ft above the ground during initial climb, the engine lost power with no abnormal noises or sounds, and he landed in a field. The airplane subsequently rolled down an embankment, the nosewheel collapsed, and the airplane then came to rest. During a postaccident engine run, the airplane started without hesitation; however, it lost power after the fuel boost pump was turned off. Further examination revealed that the B-nut to the fuel pump inlet was loose. The B-nut was tightened, and the engine then started and operated up to about 2,100 rpm with no additional anomalies. Data from the engine's data management system were analyzed, and the data revealed seven separate data sessions on the day of the accident, six leading up to the accident session. Based on the evidence, it is likely that the mechanic did not properly tighten the B-nut to the fuel pump inlet during the annual inspection and that the loose B-nut at the fuel pump resulted in the airplane being starved of fuel without the assistance of the pump. The accident likely would have been avoided if the pilot had not attempted to take off with indications that the airplane was not operating normally. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

FAA avdata. C = Cause, F = Factor.

• C Personnel issues-Task performance-Maintenance-Installation-Maintenance personnel - C
• C Aircraft-Aircraft systems-Fuel system-Fuel pumps-Incorrect service/maintenance - C
• C Aircraft-Fluids/misc hardware-Fluids-Fuel-Fluid level - C
• F Personnel issues-Action/decision-Info processing/decision-Decision making/judgment-Pilot - F