ANA B789 near Gamagori on Jan 31st 2024, turbulence injures 2 flight attendants

Last Update: July 10, 2026 / 17:08:19 GMT/Zulu time

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Photo of ANA All Nippon Airways JA899A, Boeing 787-9 Dreamliner — ANA All Nippon Airways JA899A, Boeing 787-9 Dreamliner (Photo credit: SJByles / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Jan 31, 2024

Classification
Accident

Airline
ANA All Nippon Airways

Flight number
NH-849

Departure
Tokyo Haneda, Japan

Destination
Bangkok, Thailand

Aircraft Registration
JA899A

Aircraft Type
Boeing 787-9 Dreamliner

ICAO Type Designator
B789

An ANA All Nippon Airways Boeing 787-9, registration JA899A performing flight NH-849 from Tokyo Haneda (Japan) to Bangkok (Thailand) with 257 people on board, had just climbed from FL260 to FL280 near Gamagori (Japan) when the aircraft experienced turbulence causing injuries to two flight attendants. The aircraft immediately descended to FL260 again and continued to Bangkok where it landed without further incident.

On Feb 2nd 2024 Japan's Ministry of Transport reported two days after returning from Bangkok one of the flight attendants, who had tripped during the turbulence encounter, was diagnosed with a serious injuries, a bone fracture. A second flight attendant hit her leg against a cart received minor injuries (scrapes). The JTSB have opened an investigation.

On Jul 10th 2026 the JTSB released their final report concluding the probable causes of the accident were:

The JTSB concludes that the probable cause of this accident was that it is probable that the aircraft shook during cruising flight due to encountering turbulence from cumulonimbus clouds, which caused a cabin crew member who was providing in-flight services on the left aisle of the center of the cabin to be lifted into the air and sustain a serious injury when a large load was applied to the right ankle upon landing on the floor.

The aircraft encountered turbulence due to cumulonimbus clouds is probably because, when the aircraft entered into the clouds, flight crew members were late in visually spotting cumulonimbus clouds invisible on the airborne weather radar, therefore the aircraft was unable to avoid them in time.

The JTSB analysed:

(1) Meteorological Information

The JTSB concludes that, according to the radar composite chart taken at 01:10, echoes with a precipitation intensity of about 20 - 30 mm/h, which were probable cumulonimbus clouds moving eastwards, were observed in the vicinity of the accident location, and the echo top height was about between 7 and 9 km (approximately between FL230 and FL295), therefore the aircraft flying at FL280 (approximately 8,500 m) most likely encountered these cumulonimbus clouds.

(2) Injuries to Cabin Crew Members and passenger

The JTSB concludes as follows:

According to Cabin Crew A and B, their bodies were lifted into the air when the aircraft suddenly shook violently during their in-flight services, and they sustained injuries when they fell. In addition, Cabin Crew A stated that the seat belt sign was illuminated almost simultaneously as the strong shaking began.

According to EAFR and CPL records, the seat belt sign illuminated at about 01:08:50, and a significant change in vertical acceleration was recorded during the second shaking, which occurred between approximately 01:08:49 and 01:08:51. From these points, it is probable that Cabin Crew A was lifted into the air during this period and sustained a serious injury when a large load was applied to the right ankle upon falling on the floor. Similarly, Cabin Crew B was lifted into the air, sustaining a minor injury upon falling on the floor. In addition, the seat belt sign was illuminated almost simultaneously with the second shaking, it is therefore most likely that there was not enough time for both cabin crew members to recognize the illuminated seat belt sign, suspend their in-flight services and brace for the aircraft shaking.

The reason a passenger sitting in seat 42F sustained a minor neck injury possibly due to the significant change in vertical acceleration during the second shaking.

(3) Responses of the Flight Crew Members

The JTSB concludes that, when the aircraft entered into the thin clouds in the vicinity of the airspace where cumulonimbus clouds had been forecast in advance, it is probable that the flight crew members confirmed visually and with the airborne weather radar to determine that it would be possible to avoid the echoes, and flew the aircraft with the seatbelt sign tuned off. However, as the cumulonimbus clouds that were probable to have caused the aircraft to shake were not visible on the airborne weather radar and the aircraft was flying through a zone of thin clouds, it took longer to visually spot the clouds. It is most likely that by the time the clouds were spotted, the aircraft had failed to avoid the clouds in time and entered them and encountered turbulence, resulting in shaking. It is possible that, based on the outside air temperature, most of the moisture within the cumulonimbus clouds at the aircraft’s flight altitude bands at the time of the accident consisted of ice crystals. As a result, with the airborne weather radar configured as it was at the time (Gain: 0 or temporarily +1, Tilt Control: AUTO), radar reflections from the ice crystals were absent, and consequently it is possible that no echoes were displayed on the airborne weather radar.

It is desirable that, when flight crews operate in altitude bands where the presence of ice crystals is anticipated, they temporarily switch the Tilt Control of the airborne weather radar to MAN mode (manual mode), adjust the antenna tilt angle and gain, and check for echoes of convective precipitation areas below the intermediate layer in order to avoid them and thereby reduce the likelihood of aircraft turbulence. This should be done with a thorough understanding of the characteristics of the airborne weather radar.

In this case, had information been shared between the flight crew and cabin crew regarding the prevailing weather conditions during the flight and the potential for sudden turbulence while flying through clouds, the cabin crew could have conducted in-flight service with greater caution, and it is possible that the extent of the impact would have been reduced.

It is desirable for the operator to recognize that cabin crew members are unable to directly observe external weather conditions, and to promote the sharing of information between flight and cabin crews such as weather conditions and the possibility of sudden turbulence during cloud penetration in order to ensure a common situational awareness through effective crew coordination.

(4) Improvement of Turbulence Prediction Accuracy

The JTSB concludes that, in order to reduce the risk of injury caused by turbulence, it is desirable for the company to further improve its turbulence prediction accuracy by enhancing and using the new weather information (GTG and EDR) that the company promotes.