Japan

In the accident, it is highly probable that the Aircraft lost control during flight, nose-dived while turning, and disintegrated in mid-air, resulting in the crash. It is somewhat likely that the Aircraft lost control during flight, because the captain did not have pilot skills and knowledge necessary for the operation of the Aircraft, and was not able to perform proper flight operations.

Controlled flight into terrain after the crew continued the approach in poor visibility without visual contact with the environment. Misidentification of the environment on part of the crew was a contributing factor, as well as the fact that the crew deactivated the GPWS alarm and failed to initiate corrective maneuver.

It is highly probable that this accident occurred as the speed of the Aircraft decreased during takeoff and climb, which led the Aircraft to stall and crashed into a residential area near Chōfu Airport. It is highly probable that decreased speed was caused by the weight of the Aircraft exceeding the maximum takeoff weight, takeoff at low speed, and continued excessive nose-up attitude. As for the fact that the Captain made the flight with the weight of the Aircraft exceeding the maximum takeoff weight, it is not possible to determine whether or not the Captain was aware of the weight of the Aircraft exceeded the maximum takeoff weight prior to the flight of the accident because the Captain is dead. However, it is somewhat likely that the Captain had insufficient understanding of the risks of making flights under such situation and safety awareness of observing relevant laws and regulations. It is somewhat likely that taking off at low speed occurred because the Captain decided to take a procedure to take off at such a speed; or because the Captain reacted and took off due to the approach of the Aircraft to the runway threshold. It is somewhat likely that excessive nose-up attitude was continued in the state that nose-up tended to occur because the position of the C.G. of the Aircraft was close to the aft limit, or the Captain maintained the nose-up attitude as he prioritized climbing over speed. Adding to these factors, exceeding maximum takeoff weight, takeoff at low speed and continued excessive nose-up attitude, as the result of analysis using mathematical models, it is somewhat likely that the decreased speed was caused by the decreased engine power of the Aircraft; however, as there was no evidence of showing the engine malfunction, it was not possible to determine this.

It is certain that when landing on RWY 28 at the Airport, the Aircraft undershot and the PIC commenced executing a go-around; however, it collided with the Aeronautical Radio Navigation Aids located in front of RWY 28 threshold, just before turning to climb. Regarding the fact that the Aircraft undershot, it is probable that there might be following aspects in causes: The PIC continued approaching without executing a go around while the position of the Aircraft could not be identified by visual references which should have been in view and identified continuously at or below the approach height threshold (Decision Altitude: DA); and as well, the FO, as pilot-monitoring who should have monitored meteorological conditions and flight operations, did not make a call-out of go-around immediately when he could not see the runway at DA. Regarding the fact that the PIC continued approaching without executing a go around while the position of the Aircraft could not be identified by visual references which should have been in view and identified continuously at or below DA, he did not comply with the regulations and SOP, and it is probable that there was a background factor that the education and trainings for compliance of rules in the Company was insufficient. In addition, regarding the fact that the FO did not make an assertion of go around, it is probable that the CRM did not function appropriately.

It is highly probable that the aircraft collided with the mountain slope during its in-cloud post-takeoff climb with low climb rate on its VFR flight to Kitakyushu Airport from Kumamoto Airport, resulting in the aircraft destruction and fatal injuries of two persons on board–the PIC and the passenger. It is somewhat likely that the contributing factor to in-cloud flight toward mountain slope with low climb rate is the PIC’s lack of familiarization with terrain features near Kumamoto Airport; however, the JTSB was unable to clarify the reason.

In this accident, when the airplane landed on Runway 34L at Narita International Airport, it fell into porpoising. It is highly probable that the left wing fractured as the load transferred from the left MLG to the left wing structure on the third touchdown surpassed the design limit (ultimate load). It is highly probable that a fire broke out as the fuel spillage from the left wing caught fire, and the airplane swerved left off the runway rolling to the left and came to rest inverted on the grass area. The direct causes which the airplane fell into the porpoise phenomenon are as follows:
a. Large nose-down elevator input at the first touchdown resulted in a rapid nose down motion during the first bounce, followed by the second touchdown on the NLG with negative pitch attitude. Then the pitch angle rapidly increased by the ground reaction force, causing the larger second bounce, and
b. The PF‘s large elevator input in an attempt to control the airplane without thrust during the second bounce. In addition, the indirect causes are as follows:
a. Fluctuating airspeed, pitch attitude due to gusty wind resulted in an approach with a large sink rate,
b. Late flare with large nose-up elevator input resulted in the first bounce and
c. Large pitch attitude change during the bounce possibly made it difficult for the crewmembers to judge airplane pitch attitude and airplane height relative to the ground (MLG height above the runway).
d. The PM‘s advice, override and takeover were not conducted adequately. It is somewhat likely that, if the fuse pin in the MLG support structure had failed and the MLG had been separated in the overload condition in which the vertical load is the primary component, the damage to the fuel tanks would have been reduced to prevent the fire from developing rapidly. It is probable that the fuse pin did not fail because the failure mode was not assumed under an overload condition in which the vertical load is the primary component due to the interpretation of the requirement at the time of type certification for the MD-11 series airplanes.

Controlled flight into terrain after the pilot decided to continue under VFR mode in IMC conditions.