What happened
On April 8, 2005, during a period of shifting wind conditions at Amsterdam Airport Schiphol, air traffic controllers attempted to transition runway usage to accommodate an upcoming outbound peak. During this transition, a communication error occurred between the runway controller and the second assistant. The controller intended to activate runway 36R as a landing runway alongside 36L, but the assistant interpreted the instruction as the simultaneous use of departure runways 36L and 36C.
Because the runway had not been formally requested from airport operations, runway 36R was not officially available and did not appear on the runway selection panel. Consequently, stopbars remained inactive. Under this misunderstood configuration, a Cessna 142 landed on 36R at 16:04. Shortly thereafter, a Boeing McDonnell Douglas MD-87 also landed on the same runway. During this window, a bird control vehicle was also permitted to cross the runway by the assistant.
Further complications arose when a Fokker 100 tow combination crossed the runway. The tow driver later notified platform controllers that landings were occurring on 36R, prompting an alert. Finally, a Boeing 737 landed on the unauthorized runway before the error was rectified and the runway was officially commissioned.
The investigation
The investigation examined the coordination between the runway controller, the second assistant, and the Airside Operations Manager (AOM). Investigators reviewed the handover process between shifts, noting that the outgoing assistant left the tower without clarifying the status of runway 36R. The inquiry also looked into the technical status of the runway selection panel and stopbars, as well as the impact of frequent runway availability changes on controller workload.
Findings
- A misunderstanding of verbal instructions regarding the runway configuration was the primary cause of the incident.
- The second assistant failed to verify the runway status with the runway controller before authorizing a bird control vehicle to cross.
- The runway selection panel and stopbars did not provide visual warnings because the runway had not been formally requested from the AOM.
- The frequent process of returning runways to the AOM to reduce workload created an increased risk of operating on unavailable runways.
- The handover between the outgoing and incoming second assistant lacked critical information regarding the intended use of runway 36R.
Safety action
- The investigation team recommended that air traffic control include clear operational agreements in competency and simulator training to improve situational awareness.
- It was recommended that the side effects of returning runways to the AOM be considered in the development of new runway protection policies.
- The team advised a review of supervisory structures to clearly define and publish the responsibilities and authorities of supervisors within operational services.