What happened
On the morning of January 24, 2005, a cargo Boeing 747-212B arriving from Dubai, United Arab Emirates, overran the runway at Düsseldorf Airport. During the final approach to runway 23L, the crew received information that braking action was "medium" across all parts of the runway. However, heavy snow showers had significantly contaminated the runway surface with wet snow shortly before landing.
The aircraft touched down between 1,100 and 1,600 feet beyond the runway threshold. Despite the activation of reverse thrust, the aircraft could not stop within the available distance. The overrun caused the aircraft to strike the runway end antenna, which led to the failure and subsequent fire of engines number 2 and 3. While there were no fatalities, the aircraft sustained heavy damage, and airport infrastructure was also impacted.
The investigation
The BFU investigation examined the aircraft's flight data, cockpit voice recordings, and meteorological records. The investigation focused on the sequence of weather changes, the accuracy of the braking action reports provided to the crew, and the runway's physical condition. Investigators also reviewed the evacuation process, noting that the crew had to exit the aircraft via the electrical/electronic (E/E) compartment because the primary exit was blocked and a malfunction caused the emergency slide to deploy while still inside the aircraft.
Findings
- The primary cause of the accident was that the braking action values communicated to the crew did not reflect the actual runway conditions, which had deteriorated due to heavy snowfall following the last friction measurement.
- The rapid dynamics of the changing weather conditions contributed to the discrepancy between reported and actual friction.
- The lack of a reliable method for determining braking coefficients under all weather conditions was a contributing factor.
- The runway surface was contaminated with wet snow, significantly reducing available braking effectiveness.
- An error in the installation of the emergency slide's pressure vessel caused the slide to deploy prematurely while the aircraft was still stationary at the site, obstructing a primary evacuation route.