Summary of Aircraft Accidents and Serious Incidents, and Measures
A summary of past safety troubles and measures
FY2018
Aircraft Accident
Fatal or serious injury of an person as a result of the operation of an aircraft, or an aircraft crash, collision or fire, as classified by the Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT).
Cabin attendant injured due to the turbulence on JL514
Outline
On June 24, 2018, a cabin attendant on JL514 (from New Chitose Airport to Tokyo International Airport) fell and sustained a bone fracture when encountering turbulence during cruise. None of passengers onboard was injured.
Investigation into the cause
Investigations were conducted by the Japan Transport Safety Board, and results were announced on September 26, 2019. According to their report, it is highly probable that in this accident, while the Aircraft was passing the side edge of the jet stream, it encountered clear air turbulence, which caused the Aircraft to shake greatly, and the cabin attendant in the aft passage of the Aircraft fell over and sustained serious injuries.
It is probable that the occurrence of clear air turbulence on the Aircraft was due to the existence of a vertical wind shear area on the flight route that was stronger than the forecast confirmed by the flight crew before the flight.
Countermeasures
After the accident, our company implemented the following measures promptly.
- The "Guidelines for use of seat belt signs" was revised to clarify that cabin crew should report to the flight crew and request that seat belt signs be turned on when they judge that there is a safety problem due to significant shaking of the cabin, and that flight crews should immediately turn on seat belt signs when requested.
- The following points were made known to cabin crew:
- Considering that there is always a possibility of turbulence during flight, ensure your own safety In case of Sudden Turbulence.
- Cabin crew should have a common understanding of possible service hours with flight crew and consider whether the service content is appropriate.
- Re-assign roles and responsible doors when cabin attendants are injured and unable to work.
- In the recurrent safety training for cabin attendants, we added measures to be taken in the event of turbulence to practical training.
We are also making the following efforts to enable flight crew members to more accurately grasp changes in weather conditions. - Establishment of a system that enables flight crew members to check the latest weather information on board the aircraft. The system is scheduled to be introduced in some aircraft types in FY 2019.
- Information on turbulence reported by flight crew during the flight is automatically incorporated into the ground system (Implementation expected by the end of FY 2019). All such registered information on turbulence is provided to the flight crew at the time of briefing as the latest flight route status.
Serious Incident
An incident involving circumstances indicating that there was a high probability of an accident, such as overrunning, emergency evacuation, fire or smoke inside the cabin and abnormal depressurization, encountering abnormal weather conditions, etc, as classified by the Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT).
Return to origin after take-off of JAL flight 632 case.
Outline
On May 24, 2018, Japan Airlines flight JL632 (Kumamoto Airport bound for Tokyo International Airport) experienced left engine trouble while climbing after takeoff and returned to Kumamoto Airport. Furthermore, parts belonging to the affected engine appearing to have fallen from the aircraft were discovered in the town of Mashiki in the Kamimashiki District of Kumamoto Prefecture. After landing, the plane underwent inspection, in which the rear part of the engine turbine was confirmed to be damaged, and was recognized as a “Serious Incident” on May 24 by the Japan Civil Aviation Bureau (JCAB), part of the Ministry of Land, Infrastructure, Transport and Tourism (MLIT).
Investigation into the cause
Investigations were conducted by the Japan Transport Safety Board, and results were announced on July 30, 2020. According to their report, it is presumed that the No.13 blade of 2nd stage high pressure turbine (HPT) in the No.1 (left) engine broke off during climb, and the blades and vanes backward of the broken blade were damaged, further, debris of the broken parts hit the low pressure turbine case and made a hole. As for the cause of the 13th blade broken off, it is presumed that a crack occurred at the TA area (Turning Around: bifurcation and/or turn-round area of cooling air in the blade) and progressed. It is considered that the crack on the 13th blade was caused by blister on coating layer of the blade caused by high-temperature corrosion or low cycle fatigue.
Countermeasures
After the serious incident,our company implemented the following measures.
- Urgent inspections for all 767 engines were performed in order to confirm the condition of 2nd stage HPT blades and found no damage. Further, repetitive inspections at every 200 flight cycles had been performed.
- Replaced all of the old type, which was broken off in this case, 2nd stage HTP blades with the new type blades by the end of March, 2020 (See the figure below).
Runway incursion by another aircrafts before landing of RAC 804
Outline
On June 14, 2018, two Japan Air Self-Defense Force aircrafts entered the runway before Ryuku Air Commuter(RAC) flight 804(Miyako Airport bound for Naha Airport) landing at Naha Airport. As a result, landing permission of RAC 804 was cancelled. Subsequently RAC 804 landed with a new landing permission. None of the passengers or crew was injured. This case was rated as a "Serious Incident" by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) because it corresponded to a "situation prescribed in Civil Aeronautics Law Enforcement Regulations Article 166 Paragraph 4 (Serious Incident)."
Investigation into the cause
Investigations were conducted by the Japan Transport Safety Board, and results were announced on July 25, 2019.
According to their report, it is highly probable that this serious incident was caused by two Japan Air Self-Defense Force aircrafts, which were scrambling, mistakenly following the instructions of ATC(Air Traffic Control) and that the Ryukyu Air Commuter aircraft, having obtained landing clearance, entered the runway while it was approaching for landing. It is probable that the misinterpretation of the instructions given by ATC by the two Japan Air Self-Defense Force aircrafts that were in the process of scrambling was due to the fact that the formation leader and Captain No.2 who were not used to Naha Air Base were highly conscious of taxiing on the ground at night and in intermittent rain under time pressure, were not used to the environment of lighting facilities at Naha Airport, and did not sufficiently learn the operation of radio communications at Naha Air Base.
