Beech F33A accident near Puyallup, Washington, April 18, 2015
On April 18, 2015 at about 6:00 pm local time, a 1975 Beech F33A, registered N84MD, was substantially damaged in an accident during initial climb near Puyallup, Washington (Pierce County Airport - Thun F). It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A total loss of engine power due to fuel starvation as a result of a mechanic’s failure to properly tighten the B-nut to the fuel pump inlet during a recent annual inspection. Contributing to the accident was the pilot's decision to take off despite indications that the engine was not operating normally.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 18, 2015 · about 6:00 pm local time
- Place
- Puyallup, Washington · Pierce County Airport - Thun F · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech F33A, built 1975 · all F33As on the register
- Registration
- N84MD · no longer on the register · serial CE577
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Fuel starvation during initial climb defining event
- Loss of engine power (total) during initial climb
- Off-field or emergency landing during initial climb
- Collision with terrain or object (not controlled flight into terrain) during landing (landing roll)
- Nose over/nose down during landing (landing roll)
The NTSB's findings
- cause Personnel issues › Task performance › Maintenance › Installation › Maintenance personnel
- cause Aircraft › Aircraft systems › Fuel system › Fuel pumps › Incorrect service/maintenance
- cause Aircraft › Fluids/misc hardware › Fluids › Fuel › Fluid level
- factor Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 284 hours in all; 120 in this make and model; 9 in the last 90 days; 0 in the last 30 days; 214 as pilot in command; 0 on instruments
- Last flight review: August 12, 2014
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 4,474 hours
- Last inspection: annual inspection, April 17, 2015; 0 hours since
- Maximum gross weight: 3,400 lb
- Seats: 4
- Landing gear: retractable
- Engine: Continental Motors IO 520 SERIES (piston); 4,297 hours total
The flight
- Departed from: PLU Puyallup WA at 6:00 pm
- Destination: PLU Puyallup WA
- Flight plan: none
- Runway 34, 3,650 ft by 60 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 59°F (15°C), dew point 43°F (6°C)
- Altimeter: 30.35 inHg
- Observation at 5:55 pm from KPLU
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.