Date:	Wednesday 3 January 2024
Time:	22:25 UTC
Type:	Boeing 737-8AS (WL)
Owner/operator:	Ryanair
Registration:	9H-QEN
MSN:	44827/6880
Year of manufacture:	2018
Engine model:	CFMI CFM56-7B26
Fatalities:	Fatalities: 0 / Occupants: 180
Other fatalities:	0
Aircraft damage:	None
Category:	Serious incident
Location:	København-Kastrup Airport (CPH/EKCH) -   Denmark
Phase:	Taxi
Nature:	Passenger - Scheduled
Departure airport:	København-Kastrup Airport (CPH/EKCH)
Destination airport:	Köln/Bonn-Konrad Adenauer Airport (CGN/EDDK)
Investigating agency:	HCLJ
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
Ryanair flight FR408, a Boeing 737-8AS, was involved in a serious incident with a snow removal vehicle on taxiway B in Copenhagen (EKCH).
When holding at the holding point for runway 12 on taxiway B, the tower controller (ATCO) in Kastrup Tower cleared the aircraft to cross runway 12 and continue taxiing via taxiway B to the holding point for runway 04R.
At that point, a convoy of 14 snow removal vehicles and one service vehicle performed snow removal on taxiway B. Based on issued ATCO instructions, the mission of the convoy was snow removal on taxiway B and subsequently snow removal on runway 04R.
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 of the convoy turned slightly right to clear snow in the intersection between taxiway B and taxiway E2.
This manoeuvre caused a gap of approximately 40 meters between the third from last snow removal vehicle in the convoy down to the two rearmost snow removal vehicles and the service vehicle.
The convoy stopped on taxiway B awaiting an ATCO clearance to enter runway 04R.
The two rearmost snow removal vehicles caught up with the rest of the snow removal vehicle convoy and stopped to the right of the taxiway edge marking (just outside the double yellow line).
The line-up of the convoy of snow removal vehicles on taxiway B was 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 taxiway edge marking.
There was a minor gap between the third from last snow removal vehicle in the convoy down to the two rearmost snow removal vehicles.
The flight crew noticed the involved two snow removal vehicles to the right of the taxiway edge marking.
Because of the positions of and no issued traffic information about the snow removal vehicles, the flight crew considered the vehicles to be of 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 on taxiway E2, and that an aircraft from behind approached the two snow removal vehicles. The driver expected the aircraft to turn left via taxiway B3 for the holding point for runway 04R.
The driver realised that the aircraft continued taxiing toward the positions of the two rearmost snow removal vehicles and requested the ATCO to stop the aircraft "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 the driver heard aircraft engine noise. Through the sideview mirror, the driver observed the aircraft approaching and feared a collision between the aircraft right wing and the cab of the snow removal vehicle. The driver lied down on the front seat.
As the aircraft passed, the driver heard a scraping sound from the cap top.
The ATCO instructed FR408 to hold position. The flight crew reacted and stopped the aircraft.
At that point, the aircraft had passed the two rearmost snow removal vehicles with marginal wing clearance.
The leader of the convoy of the snow removal vehicles called the ATCO, because the clearance between the aircraft right wing and the second to last snow removal vehicle was marginal.
The ATCO informed the flight crew about a potential collision with a snow removal vehicle and asked the flight crew, if they wanted a wing inspection.
The flight crew declined. Because of their close lookout throughout the sequence of events, the flight crew was positive that a collision did not occur.

CONCLUSIONS
Diverging perceptions of the traffic situation on taxiway B led to marginal clearance or a possible collision between the aircraft right wing and a snow removal vehicle.

METAR EKCH 032250Z 08028G41KT 2000 -SN BKN010 BKN014 00/M02 Q0989 TEMPO 08028G40KT 5000 BKN015=
METAR EKCH 032220Z 08027G41KT 2000 -SN BKN009 BKN014 00/M02 Q0989 TEMPO 08028G40KT 5000 BKN015=
METAR EKCH 032150Z 08027G40KT 2000 -SN SCT009 BKN012 00/M02 Q0989 TEMPO 5000 BKN008=

HCLJ

Date/time	Contributor	Updates
31-May-2024 12:13	ASN	Added
31-May-2024 12:13	ASN	Updated [Aircraft type, Location]
01-Jun-2024 07:07	ASN	Updated [Category]