Beechcraft V35 N2059W

Summary

On 16 August 2015 at about 23:55 local time, a Beechcraft V35 registered N2059W was involved in an incident near Mount Vernon, Ohio, United States. 2 people were on board and nobody was injured. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

16 August 2015 at 23:55

Classification

Incident

Location

Mount Vernon, Ohio, United States

Nearest airport

Knox County (4I3)

Coordinates

40.3289, -82.5264

Aircraft

Beechcraft V35

Registration

N2059W

Category

Airplane

Year built

1965

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Salisbury → Ann Arbor

Aircraft damage

Not recorded

Weather

VMC

Light

Dusk

NTSB number

CEN15IA365

Nobody was injured.

The loosening of the flyweight due to the installation of an improperly hardened flyweight carrier, which resulted in the overspeed of the propeller and engine and the subsequent in-flight separation of the propeller.

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

Read the full NTSB narrative

The commercial pilot was conducting a personal cross-country flight. The pilot reported that, during cruise flight, he heard a sudden high-pitched whine emanating from the engine and saw that the tachometer was reading about 3,500 rpm. He was unable to bring the engine rpm within limits and diverted the airplane to the nearest airport. During the approach, he heard a "pop," and oil covered the windscreen. After landing, he found that the propeller was missing from the airplane. A postaccident examination of the engine found metal particulates in the propeller governor. An examination of the governor revealed that a flyweight was not secured and that the flyweight carrier did not meet the factory hardness specifications. The flyweight's retaining pin hole was excessively worn, which had allowed the pin to back out and the flyweight to become loose and resulted in the overspeed of the propeller and engine and the subsequent in-flight separation of the propeller. A review of factory records did not find any similar incidents or a history of a batch of materials not meeting factory specifications. A review of the maintenance records revealed that an overhauled propeller governor had been installed on the airplane about 16 years before the accident; however, it could not be determined if the improper flyweight carrier was installed in the propeller governor during the overhaul or at some time after the overhaul.

Quoted verbatim from the NTSB record.