Stinson 108 N336C

Summary

On 17 September 2020 at about 16:54 local time, a Stinson 108 registered N336C was involved in an accident near Newport, Pennsylvania, United States. 2 people were on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

17 September 2020 at 16:54

Classification

Accident

Location

Newport, Pennsylvania, United States

Coordinates

40.5194, -77.1667

Aircraft

Stinson 108

Registration

N336C

Category

Airplane

Year built

1947

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Connellsville → Blairstown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA20LA320

1 person had minor injuries.

A total loss of engine power during cruise flight due to a disconnected carburetor mixture control cable which allowed the carburetor mixture lever to migrate to the cut-off position during flight.

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

Read the full NTSB narrative

The flight instructor stated that he and the pilot fueled the airplane, departed, and flew for about 1.5 hours when, while cruising at 3,500 ft, the engine “started to sputter.” He checked the magnetos, adjusted the mixture, switched fuel tanks, and pumped the primer and throttle. When he pumped the primer, the engine would “run for about 5 seconds then quit,” and the propeller continued to windmill. Unable to restore power to the engine, he elected to execute a forced landing to a field. During the landing rollout, the airplane impacted a berm resulting in substantial damage to the fuselage. Postaccident examination of the engine revealed that although the cockpit mixture knob was set to full rich, the carburetor mixture control cable was disconnected at the carburetor and the carburetor mixture lever on the carburetor was in idle cutoff position. The hardware that would have attached these components was not located. Given this information, it is likely that hardware holding the mixture control cable to the mixture control arm loosened and departed during flight, allowing the disconnected mixture control arm to migrate to the cut-off position, resulting in a total loss of engine power. Since both the accelerator pump and the primer system bypass the carburetor and delivers some fuel directly to the engine even when the mixture control is in the “cutoff” position, this would explain why the instructor reported momentary bursts of power when he pumped the primer or throttle.

Quoted verbatim from the NTSB record.