TAIPEI (Taiwan News) — China continued its "gray-zone" tactics by flying a spy plane into Taiwan's air defense identification zone (ADIZ) on Wednesday (Jan. 20), the same day Joe Biden was sworn in as the 46th president of the U.S.

On Wednesday morning, hours before President Joe Biden's inauguration took place in Washington, D.C., the People's Liberation Army Air Force (PLAAF) dispatched a Shaanxi Y-8 tactical reconnaissance aircraft (Y-8 RECCE) into Taiwan's ADIZ. According to the Ministry of National Defense (MND), the spy plane penetrated the southwest corner of the ADIZ northeast of Taiwan's Dongsha Islands (Pratas Islands).

In response, the Taiwanese Air Force scrambled jet fighters to intercept the Chinese intruder. The Air Force also issued radio warnings, demanding that the PLAAF plane leave the zone immediately, and tracked the aircraft with air defense missile systems.

In the month of January, Chinese military aircraft have violated the ADIZ a total of 17 times so far, including Wednesday's incursion. Since mid-September of last year, Beijing has dispatched military aircraft on sorties over Taiwan's ADIZ on an almost daily basis.

The incursions primarily occur to the southwest of Taiwan and consist of one to three planes. Most of the aircraft are prop-powered variants of the Shaanxi Y-8, which is an imitation of the Soviet Union's Antonov An-12 cobbled together through reverse engineering.

The term "gray zone" refers to the use of unconventional tools and tactics, such as covert military operations and ambiguous use of military force, to subdue an enemy through exhaustion. In this case, China has been flying aging, prop-powered reconnaissance aircraft on a daily basis in the southwest corner of Taiwan's ADIZ, with the apparent goal of making it a de facto part of China's airspace, and to wear down and degrade Taiwan's fleet of fighter jets, which are scrambled with each incursion.