Background
On 10 February 2006, a CSA Czech Airlines ATR 72-200, registration OK-XFB, was operating flight OK 606 from Prague Ruzyně Airport (LKPR) to Vienna Schwechat Airport (LOWW). After boarding and loading, the crew received clearance for pushback and de-icing at stand 38B.
Incident
At 17:27 UTC, the crew received departure clearance and information that de-icing would take place at stand 38B. At 17:31, they requested taxi from parking position 41 to the de-icing stand. Due to strong northwesterly winds, the captain requested that the aircraft be positioned nose into the wind, using taxiway H to enter stand 38B. A follow-me vehicle guided the aircraft via taxiways G, L, and H.
Meanwhile, a Dash-8-300 Austrian Airlines aircraft was being de-iced on adjacent stand 38A. The de-icing vehicle, a Ford (unit number 2807), was reversing from the Dash-8 after completing its work. As the ATR 72-200 came to a stop on stand 38B, the crew felt a jolt and saw the de-icing vehicle near the right wingtip. The right engine was still running in 'HOTEL' mode, so the captain declared a MAYDAY at 17:35:25 and initiated the 'On Ground Engine Fire' checklist. The crew also declared an unprepared emergency and requested the airport fire and rescue service via tower.
The fire service arrived, inspected the aircraft, and confirmed no fuel leak from the wing. The captain then decided against an emergency evacuation. Passengers were informed and deplaned after a bus arrived. No injuries occurred.
Damage
The rear end of the de-icing vehicle's ramp struck the right aileron and the right aileron horn balance. Damaged parts included the right aileron (P/N S57612156001901, S/N NT1076) and the horn balance (P/N 42048-E, S/N 260E). The de-icing vehicle sustained only minor damage.
Investigation Findings
The investigation by the Czech Air Accident Investigation Institute (ÚZPLN) determined the following:
- The flight crew held valid licenses and qualifications.
- The aircraft had a valid certificate of airworthiness and maintenance release.
- The ground personnel involved (follow-me driver, de-icing crew) were properly trained and experienced.
- The de-icing vehicle driver reversed without ensuring the area behind the vehicle was clear, failing to notice the ATR's wing.
- The ATR 72 was not positioned correctly relative to the stop line on stand 38B; the stop line was approximately 13 meters ahead of the aircraft's nose.
- The de-icing stand procedures were insufficient regarding capacity and safety, as the boundary between stands 38A and 38B was not marked, and orientation using the stand centerline was difficult due to snow and de-icing fluid residue.
The commission concluded that the primary cause of the incident was the de-icing vehicle driver's failure to ensure a clear path while reversing, compounded by the aircraft's incorrect positioning and inadequacies in stand procedures.