Incident Overview
Date: Sunday 4 November 1979
Aircraft Type: NAMC YS-11A-213
Owner/operator: All Nippon Airways – ANA
Registration Number: JA8729
Location: 40 nm E of Kushimoto VOR, Wakayama Prefecture –
ÿ Japan
Phase of Flight: En route
Casualties: Fatalities: 0 / Occupants: 70
Component Affected: Aircraft seat belt system (specifically, seat belt fastening mechanisms).Aircraft seat belt system (specifically, seat belt fastening mechanisms).
Investigating Agency: JTSBJTSB
Category: Accident
An All Nippon Airways (NAMC) YS-11A aircraft experienced turbulence during flight, resulting in two passenger and two flight attendant injuries. One passenger did not fasten their seat belt, while another had it loosely fastened. The turbulence was characterized by significant acceleration in wind speed, ranging from 1.67g to -0.66g over six seconds. No structural damage was observed to the aircraft.An All Nippon Airways (NAMC) YS-11A aircraft experienced turbulence during flight, resulting in two passenger and two flight attendant injuries. One passenger did not fasten their seat belt, while another had it loosely fastened. The turbulence was characterized by significant acceleration in wind speed, ranging from 1.67g to -0.66g over six seconds. No structural damage was observed to the aircraft.
Description
All Nippon Airways flight 564, a NAMC YS-11A, was en route when the aircraft encountered turbulence, injuring two passengers and two flight attendants. The “fasten seat belt” sign had been turned. One seriously injured passenger did not have his seat belt fastened and the other had his seat belt loosely fastened. The aircraft encountered turbulence from plus 1.67 g to minus 0.66 g for 6 secs. There was no damage to the aircraft. Cause: It is estimated that this accident was caused by the aircraft encountering strong turbulence that was difficult to predict while flying at cruising altitude.
Primary Cause
Strong turbulence conditions encountered during flight, particularly difficult to predict and resulting in significant acceleration in wind speed.Strong turbulence conditions encountered during flight, particularly difficult to predict and resulting in significant acceleration in wind speed.Share on:
