The International Civil Aviation Organization (ICAO) expanded the Taipei Flight Information Region one degree east in 1955 to improve air traffic control operations, but the move also created problems for Taiwan’s aviation authorities, a Civil Aeronautics Administration (CAA) official said.
Feng Ying-pin (馮英彬) said on Monday that when the ICAO demarcated Taiwan’s flight information region in 1953, the eastern border was set at 123o east.
Since airplanes at the time were slower, Taiwanese planes flying to Japan were usually unable to reach a level altitude before they left the region, forcing them to hand air control operations over to Japanese authorities.
Feng said that in consideration of the difficulty this gave air traffic control operators, the ICAO moved the eastern part of the flight information region one degree to 124o east in 1955 — which put it inside Japan’s air defense identification zone.
A country’s flight information region and its air defense identification zone are usually identical, he said, but the ICAO’s changes created an unusual situation for Taiwan and Japan.
The overlap has caused trouble for the CAA, he said, as the Japan Self-Defense Forces heighten their alert whenever a Taiwanese aircraft passes through the overlapping areas.
In 2002, for example, Japanese defense aircraft interfered with the radio transmissions of a Taiwanese plane testing a new air route through the area.
The CAA used diplomatic channels to ask Japan not to interfere with civil aircraft that had made applications to pass through the overlapping zone.
The opening of direct flights between Taiwan and China several years later made matters more complicated, as the flight path designated B591 travels through the area.
Taiwan has complied with Japanese instructions to give flight plans for all civilian aircraft flying through the zone since 2009.