Fielding questions during a legislative session, Shen told lawmakers that Taiwan's Flight Information Region (FIR) and Japan's Air Defense Identification Zone (ADIZ) narrowly overlap (between 123 and 124 degrees east longitude) in the East China Sea.
Since 2009, Japanese aviation authorities have demanded that Taiwanese airliners submit their flight plans to Japan when traveling through the overlapping air zone, Shen said.
However, despite having already identified themselves to Japanese authorities, some of these passengers planes are still intercepted by Japanese fighters in the overlapping zone, the CAA head said.
Shen said that moves made by the Japanese military have caused grave concern within the CAA because such harassment is extremely dangerous to the safe flights of passenger aircraft.
According to the CAA, such incidents occurred at least twice in 2002 and 2009.
In both occasions, Japanese fighter jets used an emergency frequency to demand that Taiwanese civilian aircraft that passed through the air zone change their course, the CAA said.
Shen made the comments during a question-and-answer session at the Legislature's Foreign Affairs and National Defense Committee yesterday.
Shen and several other senior government officials, including Defense Minister Yen Ming (嚴明), Foreign Minister David Lin (林永樂) and National Security Bureau head Tsai De-sheng (蔡得勝), were asked to attend the session to report on measures taken by the government in response to China's recent demarcation of a new ADIZ of its own over the East China Sea.
On Nov. 23, Beijing established an East China Sea ADIZ that includes the disputed Diaoyutai Islands (釣魚台), which are also claimed by both Taiwan and Japan, a move that drew intense protests by Japan and the U.S.
Patrols in East China Sea Continue: Defense Chief
Meanwhile, Yen said yesterday that Taiwan's military training operations and patrols within the portion of its ADIZ which overlaps with China's have not been affected by Beijing's latest move.
Yen told lawmakers that the Air Force over the past week dispatched more than 30 fighter jet sorties to the part of Taiwan's ADIZ that intersects with China's newly designated zone.
On the other hand, no Chinese aircraft had been detected in this overlapping zone since China announced on Nov. 23 its establishment of the new ADIZ, he noted.
Yen, however, said that the R.O.C. Armed Forces will not hold drills in the overlapping air zone, a move suggested by a ruling lawmaker who said the move could strengthen Taiwan's sovereignty claims in the disputed area.
“We will continue to carry out routine patrols to the region but we will not hold exercises to avoid escalating tensions in the region,” he said.