Accident Details
On 18 December 2018 at 19:10 local time, a Boeing 787-9 Dreamliner operated by Ethiopian Airlines (registration ET-AUP, flight ETH715) struck a light mast while taxiing into de-icing stand 991 at Oslo Airport Gardermoen, Norway. The aircraft was carrying 10 crew members and 59 passengers (including one passive crew member). The collision caused considerable damage to the outer section of the right wing, but no fuel leakage occurred.
Sequence of Events
Before departure, the crew submitted a de-icing request via datalink approximately 30 minutes prior to arrival at the de-icing platform. The aircraft pushed back and obtained taxi clearance from ground control. While taxiing via taxiways Zulu, Victor, and Sierra, the controller instructed the crew to contact de-icing services on frequency 121.855 MHz. De-icing at Gardermoen was coordinated by SAS Ground Handling (SGH) from an office located at the opposite end of the airport. Two de-icing coordinators were on duty, using ground radar, A-CDM traffic lists, video cameras, and the Wise system to assign de-icing stands.
Minutes before ETH715 approached, the coordinators discussed the traffic situation. The aircraft was incorrectly assigned de-icing stand 991, which was authorized only for Category C aircraft (maximum wingspan 36 meters). The Boeing 787-9 is a Category E aircraft with a wingspan of 60.12 meters.
As the aircraft turned into the Bravo North de-icing area, there were no markings, lights, signage, or other technical barriers to indicate that the assigned stand was unsuitable for the aircraft. The crew observed that clearance to the light mast appeared marginal, but relied on the given instructions. No anti-collision aids, such as a wingtip camera, were available to indicate insufficient clearance.
Aircraft and Stand Information
The Boeing 787-9 Dreamliner (ET-AUP) was operated by Ethiopian Airlines. The de-icing stand 991 at the Bravo North platform was designed for aircraft up to Category C (max 36 m wingspan), while the Boeing 787-9 requires Category E facilities. The Aeronautical Information Publication Norway and NOTAMs did not specify which de-icing stands at Gardermoen were authorized for the Boeing 787-9.
Investigation Findings
The investigation revealed that the de-icing coordinators lacked adequate technical aids to ensure correct stand allocation based on aircraft category. SAS Ground Handling had not, as of spring 2020, established work instructions for de-icing coordinators regarding stand allocation per aircraft category. The crew had no means to detect the error, as no physical or visual warnings existed. The Accident Investigation Board Norway (AIBN) issued three safety recommendations based on this investigation.