The Japan Transport Safety Board (JTSB) released the second progress report on the collision that occurred on January 2, 2024, at Haneda International Airport. The document analyzes factors leading to the crash between a Japan Coast Guard Bombardier DHC-8-315 and a Japan Airlines Airbus A350-941 on Runway 34R. The investigation focuses on crew fatigue, cockpit procedural errors, and technological limitations of surveillance and evacuation systems.

The technical report revealed that the Coast Guard aircraft captain experienced fatigue levels that may have compromised decision-making. Furthermore, the pilot did not operate the DHC-8 model during the 30 days prior to the accident. A fundamental finding is that the co-pilot completed the Before Takeoff Checklist, a procedure only to be initiated after receiving runway entry clearance, even though the controller only instructed the aircraft to taxi to the holding point.

The Coast Guard base at Haneda had not implemented the Sterile Cockpit Rule, allowing the crew's attention to be divided during a critical phase. Additionally, the investigation determined that a visual cross-check to confirm the final approach path was clear before entering the active surface was not performed. These systemic failures explain why the Coast Guard crew misinterpreted air traffic control instructions and occupied the runway improperly.

Haneda air traffic control failed to recognize that the Coast Guard plane invaded and remained on Runway 34R. JTSB analysis noted that the flight monitoring seat in the tower was instructed to monitor Runway A, but there was no equivalent requirement for Runway C. The lack of continuous surveillance by controllers prevented them from noticing the DHC-8 before the arrival of the Japan Airlines flight.

The investigation also questions the effectiveness of runway occupancy alerts. Experts compared this event to previous accidents where alert functions did not operate as intended or where controllers did not receive adequate training to react to these warnings. The report examines whether the safety management system of the aviation authority adequately captured deficiencies reported by operational personnel before the crash.

Visibility Experiments and HUD Usage

To understand why the Airbus A350 pilots did not see the Coast Guard aircraft, JTSB conducted field tests at Chubu Centrair International Airport in March 2025. Researchers used helicopters and small aircraft to recreate night light conditions and the final approach path on a runway with lighting systems similar to Haneda. The tests analyzed the impact of the DHC-8's white external lights, which tend to blend with runway centerline and touchdown zone lights.

The report also highlights that both Japan Airlines pilots were using the Head Up Display (HUD) at the time of impact. JTSB is studying if this equipment limited the crew's ability to maintain effective external surveillance. Data collected in simulators and test flights aims to determine at what exact point during the approach the stationary aircraft became visually indistinguishable from the runway lighting infrastructure.

Evacuation Challenges and Communication Breakdown

Although the evacuation of all 379 occupants of the Airbus A350 was successful, the report detailed critical failures in emergency equipment. The cabin PA system failed after the collision, forcing crew members to use portable megaphones. Some crew members abandoned these devices as they felt their 2W power was insufficient to overcome the noise of the still-running engines and the chaos in the cabin.

JTSB performed acoustic measurements on aircraft of the same model to evaluate voice instruction propagation under stress and ambient noise. Furthermore, they analyzed the chemical composition of the smoke that filled the cabin just five minutes after the crash, reducing visibility to a few meters and hindering passenger orientation toward emergency exits. The commission will continue analyzing damage to electrical and engine control systems to strengthen future safety protocols.