On 11 October 2013 a Boeing 737-400 aircraft operated by Tailwind, operated on a night time passenger flight from Antalya, Turkey to Zürich, Switzerland. After an uneventful landing, the aircraft taxied from runway 34 to taxiway E3 at Zurich Airport. The runways and taxiways were wet and nighttime conditions prevailed. At 04:40 UTC, the flight crew received the following instruction from the Zurich Apron ground movement manager: “Tailwind three two seven good morning taxi via Foxtrot and Charlie to stand Echo two six.” The crew immediately acknowledged this instruction.
A few metres after the aircraft had passed the turn-off for de-icing lane F2 on taxiway F, a mound of earth to the south of the commander made him feel uncertain and he turned to the right in order to cross the de-icing pad (DIP) F and join taxiway F south of it. After this 55 degree turn to the right the aircraft left the hard surface of taxiway F3 and came to a standstill on the grass triangle between de-icing lanes F2 and F3 and de-icing pad F. The aircraft could no longer move under its own power.
The airport fire brigade was alerted and the passengers were able to exit the front right door of the aircraft via the ramp stairs provided. No crew members or passengers were injured.
The Swiss Transportation Safety Investigation Board concluded that:
The serious incident is attributable to the fact that the flight crew did not follow the green centre line lights. Subsequently the aircraft left the hard surface and came to a standstill in the adjacent soft ground.
The following factors contributed to the occurrence of the serious incident:
– The taxi clearance contained no information regarding which de-icing-lane to follow when crossing de-icing pad.
– The de-icing lanes were not equipped with taxiway edge lights.
The fact that the grass areas between the de-icing lanes were almost impossible to detect in the dark and when the surface was wet promoted the occurrence of the serious incident.
- Final Report No. 2215 (PDF)