Synopsis
The Danish Accident Investigation Board (AIB) issued Bulletin 2024-30 regarding a serious incident that occurred on 3 January 2024 at 22:25 UTC at Copenhagen Airport (EKCH). The incident involved aircraft 9H-QEN, a Boeing 737-8AS, and a snow removal vehicle.
History of the Flight
The aircraft was on a scheduled IFR passenger flight from Copenhagen to Cologne Bonn (EDDK). After holding at the holding point for runway 12 on taxiway B, the tower controller (ATCO) cleared 9H-QEN to cross runway 12 and continue taxiing via taxiway B to the holding point for runway 04R. At that time, a convoy of 14 snow removal vehicles and one service vehicle was performing snow removal on taxiway B. The snow removal vehicles had their rotating lights turned on. The ATCO had visual contact with the serious incident site.
When the convoy passed taxiway B3, the two rearmost snow removal vehicles turned slightly right to clear snow at the intersection of taxiway B and taxiway E2. This created a gap of approximately 40 meters between the third-from-last vehicle and the two rearmost vehicles and the service vehicle. The convoy then stopped on taxiway B awaiting ATCO clearance to enter runway 04R. The two rearmost vehicles caught up and stopped to the right of the taxiway edge marking, just outside the double yellow line.
The line-up of the convoy consisted of eight vehicles in a displaced snow removal formation (active snow removal) and six vehicles in line (inactive snow removal) on the taxiway shoulder to the right of the edge marking. There was a minor gap between the third-from-last vehicle and the two rearmost vehicles.
The flight crew noticed the two snow removal vehicles to the right of the taxiway edge marking. Because of their positions and the absence of issued traffic information about the vehicles, the flight crew considered them no risk to the aircraft and continued taxiing on the taxiway centreline with a close lookout.
The driver of the rearmost snow removal vehicle noticed that the service vehicle suddenly turned right onto taxiway E2 and that an aircraft was approaching from behind. The driver expected the aircraft to turn left via taxiway B3 for the holding point for runway 04R but realized it continued taxiing toward the positions of the two rearmost vehicles. The driver requested the ATCO to stop the aircraft, stating, "Please stop the aircraft, the aircraft wing is right now passing just overhead the snow removal vehicle" (translated from Danish). The driver of the second-to-last snow removal vehicle did not notice the aircraft until hearing engine noise. Through the sideview mirror, the driver observed the aircraft approaching and feared a collision between the aircraft's right wing and the cab of the snow removal vehicle.
Injuries and Damage
No injuries to persons were reported. The aircraft sustained no damage. Other damage is not specified.
Meteorological and Environmental Conditions
The incident occurred in dark night. The meteorological conditions did not require Air Traffic Control separation between aircraft and vehicles on the manoeuvring area.
Investigation
The AIB conducted the safety investigation. The summary states that diverging perceptions of the traffic situation on taxiway B led to marginal clearance or a possible collision between the aircraft's right wing and a snow removal vehicle.