A summary of past safety troubles and measures
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).
On February 23, 2016 2:34 p.m. (JST), Japan Airlines flight JL3512 (operating from New Chitose airport to Fukuoka airport) during taxiing for departure, the flight was decided to return to the parking spot due to heavy snow. Later during the return at the taxiway the right engine experienced trouble, smoke entered into the cabin of the aircraft and an emergency evacuation was initiated. As a result of the evacuation, three passengers have been reported with injuries and one of the injured had bone fracture.
Investigations were conducted by the Japan Transport Safety Board, and the investigation report was disclosed on October 26, 2017. It suggests that, the passenger suffered major injuries by landing on her hip when sliding down the evacuation slide during the emergency evacuation, which was performed because small flames were observed in the rear part of the second engine when there was foul smell and smoke in the cabin while the aircraft was waiting on the taxiway due to heavy snow. The foul smell, smoke, and the flames in the rear part of the second engine were caused by heavy snow with the sudden change in weather. The engine oil leaked (*1) inside the engine because snow stayed on the fan blade and low-pressure compressor. The oil nebulized and entered into the cabin (*2), and the leaked engine oil accumulated in the exhaust causing flames in the rear part of the engine.
In addition, it is pointed out that it is desirable that the Civil Aviation Bureau of MLIT and the air carriers should inform the general users of the safety information at the emergency evacuation with its reason for the settings and study how to promote the more sound understanding and awareness, considering possibilities for other companies to have similar accident.
*1 Part of the air inlet was clogged with the snow, reducing the amount of air flowing into the engine. This reduced the pressure in the bearing compartments within the engine and as a result the engine oil leaked from the said compartments.
*2 Since part of the air is used for the air conditioning in the cabin, the leaked oil mixed with the air, nebulized, and flowed into the cabin causing foul smell having a smoke - like appearance.
JAL implemented the following measures after the accident.
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).
On April 5, 2015 (Sun.) at Tokushima Airport, a JAL aircraft was cleared for landing by air traffic control even though a car was working on the runway. The pilot noticed the car right before the wheels touched down and executed go-around.
This incident was rated a Serious Incident by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) as it corresponded to an incident under Civil Aeronautics Law Enforcement Regulations Article 166-4 (Serous Incident). None of the passengers or crew was injured.
Investigations were conducted by Japan Transport Safety Board of MLIT, and the results were disclosed on August 25, 2016. According to the report, it is highly probable that the serious incident occurred as JL455 attempted to land because local control at Tokushima Aerodrome control tower had issued a landing clearance to JL455 on the runway occupied by the Work Vehicle. It is probable that the Tower had issued a landing clearance to JL455 to land because the Supervisor, who had the combined duties of the Tower and the Ground, had forgotten about the presence of the Work Vehicle.
On June 3, 2015, All Nippon Airways (ANA) flight 1694, rejected takeoff at Naha Airport as an Air Self-Defense Force helicopter took off without ATC clearance and crossed airspace in front of ANA1694. ATC instructed Japan Transocean Air (JTA) flight 610, which was approaching the same runway, to Go Around. But JTA610 landed on the runway before ANA1694 was off the runway. None of the passengers or crew was injured.
This incident was rated as a Serious Incident by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), as it corresponded to a case of "landing on a runway occupied by another aircraft."
Investigations were conducted by the Japan Transport Safety Board, and results were announced on April 27, 2017. According to their report, it is probable that the JTA Aircraft on the runway was because the PIC, recognizing the existence of the ANA Aircraft on the runway when it started flare, as it has been issued the landing clearance by the ATC, although he could not confirm the trend of the ANA Aircraft, based on his experience at the airport and on the same type of aircraft and the landing performance, it was judged by the PIC that it could land safely. It is also somewhat likely that the judgement is related to the fact the PIC could not confirm the trend of the SDF Aircraft which had crossed over the runway. Regarding the JTA Aircraft landed on the runway although the ATC instructed it excute a go-around, it is probable that it had already landed on the runway and reverse thrust operation was started when PIC and the FO were recognizing the instruction. In addition, it is probable that it was involved that the instruction of executing go-around had missed the timing.
Japan Transocean Air took the following preventive measures against recurrence.
On June 30, 2015, Japan Transocean Air (JTA) flight 002 experienced abnormal decompression of cabin pressure during flight in the vicinity of Tanegashima. JTA002 requested priority to ATC and descended to an altitude of 3,000m. None of the passengers or crewmembers was injured, and the aircraft arrived at the destination, Kansai International Airport.
This incident was rated a Serious Incident by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) as it corresponded to "Abnormal decompression of cabin pressure".
Investigations were conducted by the Japan Transport Safety Board, and results were disclosed on October 26, 2017. According to the report, it is assumed that left-engine bleed air(*1) temperatures rose due to trouble with the precooler control valve(*2) that reduces left-engine bleed air temperature. However, as the thermostat to detect rising temperatures (450℉ thermostat) was broken(*3), left-engine bleed air flow was not regulated and bleed air temperatures continued to rise, causing the switch to detect abnormal high temperatures and shut down bleed air (490℉ switch) to activate and stop left-engine bleed air flow. As left-engine bleed air flow stopped, it is thought that burden increased on the right-engine bleed air system. As with the left-engine, it is assumed that right-engine bleed air temperatures rose due to trouble with the precooler control valve, and as the thermostat to detect rising temperatures (450℉ thermostat) was broken, right-engine bleed air temperatures continued rising, causing right-engine bleed air flow to stop.
(*1)Compressed air that is taken from the engine compressor. Used to pressurize the cabin.
(*2)Trouble was found, in which the volume of precooled air flow was inadequate compared to input from the temperature sensor due to valve deterioration.
(*3)It is assumed that the thermostat was broken before this incident, but the trouble was not found at regular inspections because the thermostat does not function when bleed air is cooled normally.
After this incident, JTA implemented the following measures on all aircraft of the same type.
(1) Conducted an emergency inspection to verify airworthiness of precooler control valves, and newly initiated regular inspection every 4,000 flight hours.
(2) Conducted modification to an improved-type bleed air temperature detecting thermostat (450℉ thermostat), and newly initiated regular replacement and inspection every 16,000 flight hours.
❊Japan Airline have implemented preventive measures on JAL-owned 737-800 aircrafts to avoid similar trouble.
On July12 2015 (Local Time), JAL flight 38 commenced take-off procedure on Taxiway at Singapore Changi Airport. Just after the acceleration, pilot noticed that they misidentified runway and aborted at once. At the same time ATC also instructed to abort and the aircraft stopped on the taxiway. None of passengers and crew onboard was injured.
This case was certified as "Serious Incident "from AAIB(*) of Singapore and MLIT of Japan on July31 2015. (* Air Accident Investigation Bureau)
The Singapore Authority (AAIB : Air Accident Investigation Bureau) disclosed on August 2016, its Serious Incident Investigation Report* concerning "Commencing Take-off procedure on a Taxiway" which occurred on July 12, 2015.
The ground movement controller (GMC) instructed the flight crew to 'taxi on the greens' to the holding point of Runway 20C. But FO appeared to have fixated on this mental picture of taxi route (i.e. one single and gradual right turn to enter R20C). FO didn't also confirm the position of the aircraft by checking the signboard & marking etc. There may be merit in ATC verbalising the specific taxi route.
Also When the GMC asked the flight crew what the latest time would be that they had to depart to meet the time restriction, the PIC misunderstood the question. He thought the ATC was asking what the earliest time would be that they needed to depart to meet the time restriction. Therefore when the runway controller (RWC) asked the flight crew to expedite taxiing, the PIC was puzzled. However, he did not query the ATC. When PIC told the time, ATC had a chance to realize that flight crew is misunderstanding to the question.
There were red stop-bar lights on taxiway before the intersection to prevent an aircraft on taxiway from taxiing beyond the intersection. However, this line of defense was breached by the flight crew. The RWC gave the clearance for the flight crew to line up and take off from Runway 20C. Had the flight crew not been issued with a take-off clearance, the error of mistaking taxiway as the departure runway 20C could have been contained.
During the course of the investigation and through discussions with the investigation team, the following safety actions were initiated by Japan Airlines and the ATC.
By Japan Airlines
By the ATC
On October 10, 2015 (Sat.) JAL crew confirmed another airline's small aircraft cut into its final approach course during descent to Kagoshima Airport after receiving landing clearance and performed Go Around.
The JAL Captain submitted a Captain's Report (report of near midair collision) according to Civil Aeronautics Law Article 76-2, and the incident was rated a serious incident by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT).
Japan Transport Safety Board, MLIT is investigating the cause of the incident. JAL is providing full cooperation with the investigations.