TOKYO: A computer breakdown in Japan's main air traffic control system temporarily grounded all domestic planes across the nation yesterday, affecting weekend schedules for more than 20,000 passengers, said officials.
The problem occurred at the Tokyo Air Traffic Control Centre, which manages 70% of Japanese airspace, said Motohiro Kaneko, a transport ministry official in charge of aviation security.
It paralysed the flight data processing system, which automatically transmits flight data including flight numbers, destination and flight routes to airports across Japan, said Kaneko.
The main system as well as its backup system went down immediately after they were turned on, grounding all domestic flights for half an hour, he said.
“We are investigating the cause of the problem.”
Although the main processing system did not recover until an hour later, several planes began departing in 10-minute intervals as the control centre managed air traffic manually.
“Since the computer was down, we had to write down flight numbers and destinations on paper and make phone calls to pilots,” said an official at the control centre.
The backup system returned to normal four hours after the breakdown, the official said.
At least 32 domestic flights were cancelled because of the problem, affecting over 20,000 passengers, and delaying the departure of some 260 domestic flights, according to Japan Broadcasting Corp and Jiji Press.
The impact on international flights at Japan's Narita airport, the main international gateway to Tokyo, was minimal as delays lasted less than 15 minutes, said a Narita airport official.
The Tokyo control centre, located in Tokorozawa, some 25km northwest of here, is one of Japan's four air control centres. – AFP