Grumman-Schweizer G-164B N3631B

Summary

On 6 July 2002 at about 16:30 local time, a Grumman-Schweizer G-164B registered N3631B was involved in an accident near Sacramento, California, 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

6 July 2002 at 16:30

Classification

Accident

Location

Sacramento, California, United States

Coordinates

38.7419, -121.5381

Aircraft

Grumman-Schweizer G-164B

Registration

N3631B

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Sacramento → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX02LA216

Nobody was injured.

Propeller blade failure due to fatigue. A contributing factor was the rising embankment.

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

Read the full NTSB narrative

After taking off and initiating a left turn at an altitude of approximately 15 feet agl, the pilot heard a "loud bang and a sharp jolt as the airplane began shaking violently." The pilot leveled the wings and reduced power; however, the vibration did not subside. He then initiated a shallow right turn in order to land on a road. "As I began to maneuver for landing I saw a burst of flame from the exhaust and heard the engine quit and felt the aircraft settle." The airplane impacted a levee and flipped over, coming to rest inverted. During post-accident investigation of the wreckage, it was noted that the outboard section of one propeller blade was missing. The inboard section of the Hamilton Standard propeller blade was sent to the NTSB Materials Laboratory Division for examination. It was reported that the blade was fractured approximately 26 to 27 inches from the butt end. Optical examination of the fracture face found features consistent with fatigue progression over the majority of the fracture. Closer examinations revealed beach marks and other progression features indicating fatigue initiation at a mechanical dent on the camber surface near midspan. Further examination indicated that fatigue accounted for approximately 70% of the total fracture area.

Quoted verbatim from the NTSB record.