A Boeing 737-900 was operating a scheduled passenger flight from Incheon Airport (Seoul, South Korea) to Niigata Airport (Japan). With 115 occupants (9 crew and 106 passengers the aircraft took off at 18.09 lt (local time) for the 1-hour 46-minute flight to Japan. The captain was the pilot flying (PF) while the co-pilot was the pilot monitoring (PM) for the flight.
The aircraft in its final position after coming to a stop (Source avherald.com © Unknown)
Approximately 1 1/2 hours after take-off the crew contacted Niigata Tower, they were instructed by ATC to continue their approach to runway 10. At the time the aircraft was descending through 2900 feet at an airspeed of 194 knots while turning on the final approach course. Less than a minute later ACT issued the landing clearance to runway 10, stating the wind was 040º at 4 knots, which was read back by the crew. At an altitude of ~1000 feet, with an airspeed of 151 knots, the autothrottle was disconnected. Immediately followed by the EGPWS call out "One Thousand" (Radio Altitude of 1000 feet). When the EGPWS call out "Minimum" was announced the captain announced "Landing". The automatic EGPWS altitude call-outs continued as normal and at 19.40 lt the aircraft touched down with an airspeed of 143 knots, the maximum vertical acceleration recorded at touch down was 1.34 G. The speed brakes (spoilers) started to extend automatically, and brake pressure increased, reverse thrust was selected. Once the thrust reversers were fully deployed, maximum reverse thrust was selected.
The main landing gear is on the edge of the runway stopway, note the damaged runway end lights (© JTSB)
At 88 knots reverser levers were returned to the idle reverse position, followed by the retraction of the spoilers at 73 knots. The brake pressure dropped and the deceleration rate rapidly decreased, The brake pressure rapidly increased 8 seconds later and the deceleration rate started to increase. This was too late to stop the aircraft on the runway. The nose landing gear ran off the end of the runway, after which the aircraft stopped, with the main gears still on the paved runway area. The aircraft had a ~4º pitch-down attitude. The captain ordered a shutdown of the engines. After the engines were shut down the crew discussed the situation, headlines of the discussion were;
The Captain and the F/O assumed that the red lights might be the stop bar lights for the intersecting runway 04/22 (hereinafter referred to as “RWY 04/22”), and they tried to continue to proceed beyond those lights.
The Captain and the F/O could not accurately recognize where the taxiways and intersecting RWY 04/22 were located.
The Captain and the F/O did not see the runway distance marker lights.
The Captain thought that he should have reduced speed earlier.
The Captain disarmed the Auto Brake by stowing the speed brake (spoiler) lever.
Since the Captain intended to continue rolling to the end of the runway, the Captain was going to reduce speed slowly after the auto brakes were disarmed.
The aircraft in its final position seen from the river (© JTSB)
The runway overrun was reported to and investigated by the Japan Transport Safety Board. In their report, which was published on the 9th of January, 2015, an extensive investigation into the overrun is described.
They concluded the report with an extensive description of the probable causes. It is highly probable that this serious incident occurred when the Aircraft landed on runway 10 in Niigata Airport, the Captain did not let the Aircraft reduce enough lower speed to approach the runway threshold lights that the Captain understood as the stop bar lights for the intersecting runway 04/22, which the Captain was holding a doubt, and when the Captain realized there was no runway beyond the red lights, the Aircraft could not stop within the runway anymore, resulting in overrunning.
It is highly probable that the reasons why the Captain understood the runway threshold lights as the stop bar lights for the intersecting runway 04/22, and why the Captain did not let the Aircraft reduce enough lower speed to approach the lights, are as follows:
Both the Captain and the F/O presumed that the ATC instruction “cross runway 04/22” from the Niigata Tower was “the clearance to cross the intersecting runway during landing roll” rather than “the taxi clearance including crossing the intersecting runway after vacating the runway,” unable to understand the intention of the instruction, and both of them believed the Aircraft was short of the intersecting runway.
The Captain was going to roll to the end of the runway; therefore, he disarmed the auto brakes as fast as about 70 kt. After that, the Captain could not take appropriate control of reducing the speed with manual braking, even though he should have reduced speed in a careful manner.
Diagram of the landing roll with the different events and call-outs while on the runway (© JTSB)
It is also somewhat likely that the following reasons contributed to the occurrence of this serious incident:
The Captain and the F/O were not familiar with Niigata Airport which had a the intersecting runway and they had difficulty identifying the intersecting position with runway 04/22 because ground objects that the pilots could observe during the night landing were limited. In such circumstances, it was difficult for them to judge the speed of the Aircraft in the low-speed area in which they did not rely on the airspeed indicator.
The full JTSB report is available for the readers' reference by clicking on the .pdf file below;