56 Chinese warplanes flew into Taiwan's Air Defense Identification Zone (ADIZ) on Oct 4, 2021, the largest incursion since the island first started reporting such activity in September 2020. The aircraft involved were 38 J-16 fighter jets, twelve H-6K bombers, two Y-8 anti-submarine aircraft and two KJ-500 warning and control aircraft, among others. Taiwan's Ministry of Defense stated that it used its own fighter jets and missile systems to monitor the Chinese activity with radio warnings issued.
Such incidents are hardly rare and Chinese warplanes have been known to cross the sensitive median line unofficially separating the airspace of the island and the mainland. What makes the early October incident notable is the sheer number of Peoples Liberation Army Air Force (PLAAF) aircraft involved. The scale and frequency of Chinese aerial activity has grown since the beginning of 2021. October was a particularly busy month with the first of the month seeing 38 and Oct 2 seeing 39 incursions, respectively.
Since then, Chinese incursions into Taiwanese airspace have not been as intense, but have become more persistent, as our chart shows.
All of this activity has heightened fears of a military clash with China, which considers Taiwan a rogue province. The tensions have had regional and international observers on their toes, with the invasion of Ukraine by Russia refocusing attention on similar potential scenarios around the globe. During his ongoing visit to Asia, U.S. President Joe Biden meanwhile said that his country would help defend Taiwan in the case of a Chinese invasion.