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 November 26, 2012, a passenger onboard JAL877 (Narita to Shanghai Pudong) fractured his right instep when the aircraft encountered turbulence while cruising.
Investigations were conducted by Japan Transport Safety Board of MLIT, and the results were announced on May 30, 2014. According to the report, the probable cause is the aircraft's encounter with turbulence that rocked the aircraft, and also considers that it was difficult to predict the occurrence of turbulence.
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 July 8, 2012 (Sun.) at Fukuoka Airport, while a small Cessna aircraft was making its approach after cleared for landing, Japan Air Commuter (JAC) flight 3635 was instructed by the air traffic controller on ATC to enter the runway and hold. Consequently JAC 3635 entered the runway. This case was classified as a Serious Incident by MLIT, as it corresponded to "an attempt to land on a runway used by another aircraft."
Investigations were conducted by Japan Transport Safety Board of MLIT, and the results were announced on April 26, 2013. According to the report, this incident was caused by the air traffic controller who had momentarily forgotten about the other aircraft.
On October 20, 2012, JAL1471 (Haneda-Matsuyama) rolled slightly from side to side during climb after take-off from Haneda. And furthermore, the exhaust gas temperature gauge of the left engine suddenly rose. The flight crew shut down the left engine, then turned back to Haneda Airport on declaring an emergency to air traffic control. There were no injuries.
With inspection, damages were found in several high pressure turbines and low pressure turbines, and high pressure compressors.
This case was classified as a Serious Incident, as it corresponded to "engine damage (when large-scale damage occurs inside the engine)."
It is highly probable that the major damage to inside of the Engine was caused by all the blade tips in the fifth stage of High Pressure Compressor (HPC) of the JA342J coming into contact with the HPC casing, resulting in a heavy load applied to the blade roots to produce cracks; consequently, they were propagated by the repeated loads from the flight cycles, and resulted in separation of all blades airfoils in the fifth stage of HPC.
With regard to the fact that all the blade tips in the fifth stage of HPC coming into contact with the HPC casing, it is somewhat likely that the clearance between the blade tips in the fifth stage of HPC and the casing became smaller due to the influence of the water accumulation in the cavities at the bottom of the fifth stage HPC casing, and also the clearance between them becoming smaller than usual for some reason at the time of the occurrence of this serious incident.
JAL's countermeasure and JAL implemented the following measures after this incident.
Measures implemented by the engine manufacturer :
On February 28, 2014, the design was changed to widen the clearance between HPC 5th stage blades and the casing.
JAL's countermeasures after the accident :
JAL implemented bore scope inspections, etc. of all engines of the same type installed on aircraft to examine inside the engine including HPC, and have confirmed that similar problems will not recur.
On October 31, 2012, Japan Air Commuter (JAC)3745 landed at Yakushima Airport and before it vacated the runway, a private helicopter waiting to depart from the runway actually took-off.
The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) rated the occurrence a Serious Incident, because it corresponded to "take-off from a runway occupied by another aircraft".
None of the passengers or crew was injured.
Investigations were conducted by Japan Transport Safety Board of MLIT, and the results were announced on December 20, 2013.
According to the report, the incident was caused by various factors of the helicopter side, such as the captain's assumption that there was no aircraft on the runway. It was confirmed that there were no problems on the JAC aircraft side.
On December 25, 2012, after landing at Hanamaki Airport, nose tires of JAL2837 (operated by J-AIR) ran off the side of the runway while decelerating and the aircraft came to a halt. This incident was rated a Serious Incident by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), as it corresponded to 'runway excursion' (limited to when an aircraft is disabled to perform taxiing).
None of the passengers or crew was injured.
The probable cause is that at landing, the aircraft could not maintain the direction of movement while running on the ground after touchdown and veered off the runway to the left. The probable reason that it could not maintain the direction of movement is that the Captain suddenly pressed on the rudder pedal on the runway, which was more slippery, at the time of inspecting snow and ice conditions, due to snow in temperatures near the freezing point.
J-Air implemented the following measures after this incident.
(1) Cautioned all flight crew to "strive to obtain the latest information on runway conditions," "refrain from operating the rudder suddenly as much as possible to correct the direction of the aircraft," and "proactively use idle reverse on runway conditions with low braking action."
(2) Conducted training using the simulator for all flight crew concerning landing operation on a snowy and icy runway under more severe conditions.
(3) Cautioned all operation officer to "check latest conditions of snowy and icy runways and be sure to report information to flight crew" and "be sure to contact and coordinate in detail with airport supervisor"