Beechcraft D-45 N20869

Summary

On 29 May 1999 at about 21:00 local time, a Beechcraft D-45 registered N20869, operated by Travis AFB Aero Club, was involved in an accident near Lake Berryessa, California, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

29 May 1999 at 21:00

Classification

Accident

Location

Lake Berryessa, California, United States

Coordinates

38.2790, -121.9190

Aircraft

Beechcraft D-45

Registration

N20869

Category

Airplane

Engines

1

Operator

Travis AFB Aero Club

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Travis Afb → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX99LA202

Nobody was injured.

Loss of engine power due to a loose adjustment nut on the engine driven fuel pump that allowed for a decrease in fuel flow and fuel pressure, and the subsequent failure of the electric fuel boost pump due to loose bearings decreasing fuel flow and fuel pressure to sustain engine power.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The purpose of the flight was to fly over the lake with the intent of viewing the lake and surrounding area. The lake is 10 miles from the airport. Approximately 30 minutes into the flight the pilot noted a loss of fuel pressure followed by a rough running engine. He believed that the engine driven fuel pump had failed. He engaged the electric boost pump and the fuel pressure came back on-line and engine ran normally. The pilot decided to return to the airport to make a precautionary landing. He again noted that the fuel pressure gage needle began to move sporadically and the engine began to run rough and subsequently lost power. He made an unsuccessful attempt to restart the engine utilizing the in-flight engine failure checklist and subsequently ditched the airplane in the lake. No discrepancies were noted with the flight prior to the loss of engine power. The fuel system was inspected with no foreign debris found. A functional check was performed on the electric boost pump and no fuel flow output was observed; however, during the test the pump shorted out. Both the engine driven fuel pump and electric boost pump were sent out for further tests. Two functional checks were conducted on the engine driven fuel pump. An adjusting nut on the engine driven fuel pump allows for an increase or decrease in fuel flow. The first test was completed in the as-received condition with the adjusting nut loose. The results were consistently low, but fuel flow output was observed from the pump. The adjusting nut was then readjusted to overhaul specifications for the second functional check. The check revealed that the fuel flow was within overhaul specifications. During the teardown of the electric boost pump, it was noted that the bearings were loose allowing the pump vanes to rub up against the throat of the pump, decreasing fuel flowing through the fuel system.

Quoted verbatim from the NTSB record.