TOKYO -- A labour union representing air traffic controllers in Japan has called for a "significant increase" in staff to improve the safety of operations at airports in the wake of a deadly crash at Tokyo's Haneda airport last month.
The statement issued late on Tuesday by the chair of the transport workers' union executive committee did not say staffing issues contributed to the Jan. 2 crash between a Japan Airlines jet and a smaller Coast Guard turboprop.
An investigation is ongoing into the runway collision at the world's third-busiest airport in which all 379 people on board the Airbus A350 passenger jet miraculously survived, but five of the six crew on the smaller Coast Guard aircraft died.
Authorities have released control tower transcripts showing the Coast Guard plane was ordered to go to a holding area on a taxiway near the runway as the JAL plane came into land, but questions remain as to why the plane then entered the runway seemingly unnoticed.
"We strongly urge the realisation of a significant increase in the number of air traffic controllers," Masato Yamazaki said in the statement, adding that speculation about the cause of the crash risked putting mental strains on controllers.
As an emergency measure in the wake of the accident, authorities ordered air traffic control towers at Haneda and other airports across the country to constantly monitor radar systems for possible runway intrusions.
Yamazaki said this was further burdening stretched staff, although he said he was hopeful the ministry would make fresh hires to fulfil this function.
He said repeated staffing requests to the government, which directly employs air traffic controllers in Japan, have been only partially approved in recent years despite increased workload on controllers.
"It is not enough to establish true safety," he said.
Japan's transport ministry was not immediately available for comment.
Other countries including the United States and France are grappling with air traffic control staff shortages that airlines have argued pose risks to aviation safety.
Last year, the number of air traffic control staff in Japan dropped to its lowest level in at least 19 years, according to transport ministry data, continuing a gradual decline over that period.
Aside from a sharp fall in the number of flights during the COVID pandemic, the number of flights handled by each operator has been steadily increasing. In 2019, each air traffic control operator in Japan handled nearly 7000 flights, up from around 4,600 in 2004, according to the ministry's records.