Cessna 172 N8033B

Summary

On 1 April 2013 at about 17:20 local time, a Cessna 172 registered N8033B was involved in an accident near Wonewoc, Wisconsin, United States. One person was 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

1 April 2013 at 17:20

Classification

Accident

Location

Wonewoc, Wisconsin, United States

Nearest airport

Three Castles Airpark (4D1)

Coordinates

43.6700, -90.2325

Aircraft

Cessna 172

Registration

N8033B

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Park Falls → St Jacob

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN13LA216

Nobody was injured.

The restricted vented fuel cap and obstructed fuel vent lines, which resulted in a total loss of engine power due to fuel starvation.

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

Read the full NTSB narrative

The pilot reported that, during the flight before the accident flight, the engine began running roughly during cruise flight with the right wing fuel tank selected. After attempting to resolve the issue by applying carburetor heat, he made a precautionary landing at a nearby grass airstrip. After landing, the pilot loosened the right fuel tank cap and heard a "whoosh" sound and the metal fuel tank "crinkle." The pilot stated that he thought he had resolved the fuel tank venting issue when he removed the right fuel tank cap. After spending 30 minutes on the ground, the pilot restarted the engine with both fuel tanks selected and performed an uneventful engine run-up before departing. Shortly after takeoff, the engine experienced a total loss of power, and the pilot executed a forced landing into a marsh. A postaccident examination revealed that the external and cross-tank vent lines were obstructed by foreign material likely deposited by insects. In this condition, the engine responded to cockpit controls during an operational test run. Following the engine test run, the right fuel tank cap was loosened, and a "whoosh" sound was heard. Testing of the right fuel cap revealed a restriction to the flapper-valve assembly, which prevented air from passing freely through the vented cap as designed. The combination of a restricted vented fuel cap and the obstructed vent lines likely prevented the fuel from flowing to the engine and resulted in fuel starvation and the total loss of engine power.

Quoted verbatim from the NTSB record.