Embraer BRASILIA EMB-120 N223AS

Summary

On 23 December 1986 at about 12:20 local time, a Embraer BRASILIA EMB-120 registered N223AS was involved in an incident near Fort Smith, Arkansas, United States. 6 people were on board and nobody was injured. The aircraft was slightly damaged. No probable cause statement is available for this record.

Date

23 December 1986 at 12:20

Classification

Incident

Location

Fort Smith, Arkansas, United States

Nearest airport

Fort Smith Municip

Coordinates

35.3699, -94.4201

Aircraft

Embraer BRASILIA EMB-120

Registration

N223AS

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 135: Air Taxi & Commuter

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Fayetteville → Fort Smith

Aircraft damage

Minor

Weather

VMC

Light

Dawn

NTSB number

MKC87IA034

Nobody was injured.

The NTSB has not published a probable cause for this record. No probable cause statement is present in the source data.

Nothing about the cause is stated here that is not in the source record.

Read the full NTSB narrative

THE FLIGHT CREW STATED THAT THEY WERE INITIATING A DESCENT INTO FINAL APPROACH FOR A LANDING WHEN THE RIGHT ENGINE GEARBOX CHIP DETECTOR LGITH ILLUMINATED FOLLOWED BY A LOUD BANG AND SEVERE VIBRATION.WHEN THE PROPELLER WAS FEATHERED AND THE ENGINE SHUT DOWN WITH THE CONDITION LEVER THE ROTATION AND VIBRATION STOPPED, THE CREW FURTHER STATED. THE AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. A POST-INCIDENT TEARDOWN INSPECTION OF THE POWERPLANT AT THE FACTORY REVEALED A SUDDEN AND CATASTROPHIC FAILURE OF THE PROPELLER REDUCTION GEARBOX ASSEMBLY DUE TO A HIGH CYCLE, METAL FATIGUE FRACTURE ON ONE, OF TWO, HELICAL GEARS. TEARDOWN AND INSEPCTION OF THE PROPELLER ASSEMBLY REVEALED SEVERE DAMAGE TO THE COMPOSITE PLASTIC BLADE RETAINER RINGS AND METAL ACTUATOR YOKES DUE TO SUDDEN DECELERATION AND STOPPAGE.

Quoted verbatim from the NTSB record.