Pilots had 500 near miss alerts - report

Pilots in Japanese airspace reported more than 500 cases last year of on-board computers warning them to change course to avoid colliding with other aircraft.

The report came as the government and police investigators entered the second day of a probe into the cause of a 33ft near miss between two Japan Airlines planes on Wednesday.

Forty-two people were injured in the incident over central Japan when one of the planes dived steeply to avoid catastrophe.

Most commercial aircraft operating in Japanese airspace are required to have a radar-based based system designed to warn pilots 25 to 40 seconds before a possible collision with another aircraft and provide instructions for evasive action.

One focal point of the investigation into Wednesday’s near miss was why one of the pilots dived instead of pulling up as advised by his Traffic Collision Avoidance System.

Citing figures from the Transportation Ministry’s Civil Aviation Bureau, the mass-circulation Asahi newspaper said that pilots in Japan last year reported more than 500 incidents in which their TCAS anti-collision systems warned them to take evasive action.

Only three cases were classified as near misses, however. Pilots in Japan are required to report near misses only when they judge that that an in-flight collision was ‘‘dangerously close’’, the newspaper said.

Officials at the Civil Aviation Bureau’s Air Traffic Control Division official were not immediately available to comment on the report.

The three near misses included one near the Japanese island of Okinawa in which an Air Nippon jet carrying 108 people reported that a US Navy F-18 jet passed as close as 198 feet.

Less than five near misses have been reported annually in Japan since 1996, said Takahide Zenigame, an official in the bureau’s Safety Inspection Division. All jets that carry 30 passengers or more must be equipped with the TCAS anti-collision systems, he said.