American Champion 7GCBC N255SF

Summary

On 3 July 2013 at about 16:40 local time, a American Champion 7GCBC registered N255SF, operated by Kcsi Aerial Patrol Inc, was involved in an accident near Lufkin, Texas, 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

3 July 2013 at 16:40

Classification

Accident

Location

Lufkin, Texas, United States

Nearest airport

Angelina County (LFK)

Coordinates

31.1478, -94.7708

Aircraft

American Champion 7GCBC

Registration

N255SF

Category

Airplane

Year built

2000

Engines

1

Operator

Kcsi Aerial Patrol Inc

Operating rule

Part 91: General Aviation

Purpose of flight

Aerial Observation

Phase of flight

Not recorded

Route

Angleton/Lake Jackson → Lufkin

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN13LA406

Nobody was injured.

The restricted movement of the carburetor’s forked needle valve within its seat due to the mechanic’s misadjustment of the valve clip forks, which resulted in fuel starvation.

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

Read the full NTSB narrative

The pilot was flying a pipeline patrol flight about 500 feet above ground level. About 6 miles south of the destination, the engine abruptly lost power. The pilot observed that both fuel tanks contained a usable level of fuel. Additionally, he saw no obvious issues with the mixture setting, carburetor heat, magnetos, throttle position, and fuel shutoff valve. The pilot landed the airplane in a field with high vegetation, which resulted in strut damage. The pilot did not report any fuel or oil leaks. During a postaccident examination, the engine was intermittently operational. The engine would produce power when the carburetor was "tapped" after the engine stopped. A carburetor examination revealed that the accelerator pump was operational and that the fuel screens were clear of debris. However, the forked needle valve's movement within its seat was restricted. The valve clip forks were observed resting on the valve seat when the carburetor's throttle body was inverted. The carburetor maintenance manual specified that a minimum clearance must exist between the forked valve clip and the valve seat. It is likely that the restricted movement of the carburetor's forked needle valve resulted from the mechanic's misadjustment of the valve clip forks, which subsequently caused the engine to lose power due to fuel starvation.

Quoted verbatim from the NTSB record.