Summary
On 11 December 1993, a Garuda Indonesia Boeing 747-200, registration PK-GSD, overran the end of runway 14 at Zurich Airport during landing. The flight was from Abu Dhabi to Zurich with an intended stopover. The cockpit crew consisted of a pilot-in-command (PIC) acting as assisting pilot, a captain-in-training as pilot flying, a supervisor captain on the jump seat, and a flight engineer. The aircraft carried 253 passengers and 17 flight attendants. No injuries were reported.
Flight History
The flight departed Abu Dhabi with a delay due to a hydraulic pump issue. During descent, the crew received ATIS information indicating variable weather with visibility of 1200 meters and precipitation of rain mixed with snow. While holding at FL90 over Schaffhausen, the crew obtained wind of 21 knots, RVR of 900 meters, and a heavy snow shower. The PIC decided to continue the approach. The aircraft briefly descended 400 feet below the assigned altitude, but corrected after a tower warning.
Radar guidance to the ILS for runway 14 was provided. The crew was informed that the runway was covered with 3 mm of snow grains and slush and that braking action was unreliable. The pilot flying selected auto brake MED, which the PIC approved. The approach was flown manually with flight director, without autopilot or autothrottle. The PIC repeatedly alerted the pilot flying to deviations from the glideslope and localizer.
Landing clearance was issued with wind 290 degrees at 16 knots and RVR touchdown 1000 meters. The PIC called for descent three times, and the GPWS sounded "sink rate" three times. The aircraft touched down approximately 1300 meters beyond the threshold, at the intersection with the satellite road, 19 knots above the target speed of 131 knots.
After 2 seconds, reverse thrust was selected on all four engines, with full reverse on engines 2 and 3. After 13 seconds, the PIC applied full manual braking, and after 22 seconds, full reverse on all engines. The aircraft came to a stop on soft ground 100 meters beyond the runway end. The aircraft sustained light damage, and runway lighting was damaged.
Investigation Findings
The investigation determined that all crew members held valid licenses. The aircraft was airworthy with no open technical defects. The landing mass of 230,311 kg was within the structural limit of 285,762 kg. The calculated landing field length for the conditions was 8,300 ft, while the runway is 10,826 ft long. The maximum tailwind component during touchdown was 20 knots, exceeding the aircraft operating manual limits of 10 knots for good braking action, 5 knots for medium, and 0 knots for poor. The runway condition was reported as 3 mm of snow grains and slush with unreliable braking action.
Causes
The incident was attributed to:
- False estimation of weather and runway conditions by the crew;
- Loss of situational awareness due to stress;
- Unstabilized approach combined with exceeding the maximum tailwind component;
- Excessive passivity of the PIC in his role as copilot (omission to go around);
- Not using deceleration possibilities optimally.