Schiphol's hours-long fuel outage caused by a loose wire

A major fuel outage at Schiphol in July, that left hundreds of flights canceled and tens of thousands of travelers stranded, was caused by a loose neutral wire in an electrical installation, research agency TNO concluded after investigating the failure. According to TNO, the error likely occurred during electrical installation work in February, NOS reports.

The neutral wire ensures that electricity is drained from electrical appliances. Because this one neutral wire was not properly connected, this was not possible, leading to overvoltage in some connected systems. The loose neutral wire had no effect until the fuel supply's installation was connected to it during maintenance work on July 24th. Various power supplies and components were burned out as a result.

That made it impossible to refuel any planes at Schiphol Airport for a period of 8.5 hours on July 24th. Around 200 flights were canceled on that day, and 100 more on July 25th. Tens of thousands of travelers were left stranded. Apart from the extremely long waiting times, travelers also complained about a lack of clear communication about what was going on.

On August 9th there was another fuel failure at the airport, this one lasting 1.5 hours. TNO could not find the cause of this failure, but called it "unlikely" that it was connected to the failure on July 24th.

In both cases airport workers followed the procedures, the researchers concluded. But "the available procedures offer little support for a multiple technical failure". According to TNO, research must be done into how to improve the security of supply, for example by making it possible to manually refuel aircraft.

TNO investigated the failures at the request of Schiphol and Aircraft Fuel Supply, the company responsible for fuel supply at the airport.