Piper J3C-65 N59931

Summary

On 9 October 1995 at about 16:30 local time, a Piper J3C-65 registered N59931 was involved in an accident near Tucson, Arizona, 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

9 October 1995 at 16:30

Classification

Accident

Location

Tucson, Arizona, United States

Nearest airport

Ryan Field (RYN)

Coordinates

32.1497, -110.9301

Aircraft

Piper J3C-65

Registration

N59931

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX96LA005

Nobody was injured.

fuel starvation due to swelling of the carburetor needle valve tip, which restricted the fuel flow to the carburetor inlet. A factor in the accident was the use of automotive gasoline.

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

Read the full NTSB narrative

During the takeoff initial climb, the engine lost power and the airplane collided with trees short of the intended forced landing area. Examination of the airplane revealed that it was using automotive gasoline. During a test run the engine operated at full rpm, then began to lose power output (300 to 400) rpm. Carburetor heat was applied, and the engine gained partial return of power. When the carburetor heat was removed, the engine returned to the previous running condition. A float level problem was suspected, and the carburetor was sent out for analysis at an overhaul shop. The aircraft owner subsequently decided to replace the carburetor with a different type, and the accident carburetor was lost in the overhaul process. Information Letter 8401 (12/15/84) from the EAA advises of a long standing problem with rubber tipped needle valves which swell when exposed to automotive fuels. The letter states that slow degeneration of in-flight engine power has been observed when the rubber needle valve tips swell and decrease the orfice size at the carburetor inlet. Sudden losses of power have also been reported during takeoffs in aircraft following a long period of inactivity.

Quoted verbatim from the NTSB record.