Beechcraft 1900D N832CA

Summary

On 4 May 1998 at about 13:25 local time, a Beechcraft 1900D registered N832CA was involved in an incident near Syracuse, New York, United States. 14 people were on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

4 May 1998 at 13:25

Classification

Incident

Location

Syracuse, New York, United States

Nearest airport

Syracuse Hancock Int'l (SYR)

Coordinates

Not recorded

Aircraft

Beechcraft 1900D

Registration

N832CA

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Boston

Aircraft damage

Minor

Weather

VMC

Light

Day

NTSB number

NYC98IA106

Nobody was injured.

Improper maintenance which resulted in a cross threaded\ mistapped counterweight bolt hole, and the subsequent failure of the propeller counterweight clamp assembly. Also causal was the inadequate inspection of the counterweight clamp threads by maintenance personnel which failed to detect the damaged counterweight threads.

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

Read the full NTSB narrative

After takeoff, the pilot heard a 'loud bang' followed by severe vibration. The pilot returned and landed at the departure airport without further incident. Examination revealed the left engine's number two propeller counterweight had separated, and exited through the propeller spinner. The counterweight then impacted the number one propeller blade, of the left engine, which separated about 12 inches from the hub. Examination of the counterweight clamp leading edge bolt hole revealed that the internal threads in the hole were stripped by motion of the leading edge bolt out of the hole. Additionally, the hole contained a double set of thread roots, indicative of cross threading of a bolt or mistapping of the threads. The propeller counterweight bolts had been replaced during an overhaul performed by the propeller manufacturer on April 12, 1995. The propeller counterweight bolts were also replaced by a certified propeller repair station, during maintenance on April 8, 1996, and at the last overhaul, which was performed on January 28, 1997. According to the propeller overhaul manual, after removal of a counterweight clamp bolt, an undersized tap should be used to remove the loctite retaining compound which was to be applied to the counterweight clamp threads during installation. The manual also stated '...Visually inspect threads for damage. Cross threading, damaged or missing threads is cause for retirement of the clamp.' A representative from the propeller repair station stated that their mechanics use a compressed air plastic bead spray to clean the clamp threads and they do not use an undersized tap. According to the propeller manufacturer, the use of a compressed air plastic bead spray to clean the propeller counterweight clamp threads was not an approved procedure.

Quoted verbatim from the NTSB record.