Since October 1, Chinese military aircraft have flown 159 times through Taiwan’s air defense identification zone (ADIZ)–a section of international airspace countries can arbitrarily define as theirs to monitor.
The aircraft have never entered Taiwanese airspace or crossed over Taiwanese territory. And the tempo at which the People’s Liberation Army Air Force (PLAAF) and People’s Liberation Army Navy (PLAN) are sending planes into the air does not necessarily indicate improvements in China’s airpower modernization and capabilities.
As recently as five years ago, a RAND report found that although China’s air force had been able to put large numbers of aircraft in the air during training–it cites a 2002 exercise in Chengdu in which 85 planes took off and landed in less than five and a half hours–there were organizational problems that prevented such high tempos from being the norm. “This event remains an unusual exception to the general practice of logistics and maintenance, which remains defined by the persistence of legacy practices, habits, and equipment,” the authors wrote.
Although the number of Chinese aircraft probing Taiwan’s ADIZ increased dramatically in recent weeks, including 56 on Oct. 4, it does not mean the rate at which China’s military can launch an aircraft, get it back on the ground, get it ready for the next mission and launch it again–its “sortie generation rate”–has improved since that time.
Because the identification numbers of each Chinese aircraft are not always known, it’s difficult to tell whether the same planes from the same bases are being used for ADIZ missions over and over. The planes’ transponder data, which would show what bases they fly from, is rarely public. But the pressure such missions are putting on both Taiwan’s air force and the PLAAF is clear. Taiwan’s air force had several mishaps, including three fatal crashes, in 2021. In March, a senior Taiwanese official said they had stopped intercepting every Chinese aircraft. The wear and tear of repeated flights can also take a toll; the engines in Chinese fighter planes have a lifespan only about one-fourth that of a U.S. fighter, according to Ken Allen, former research director for the U.S. Air Force’s China Aerospace Studies Institute.
“The PLA’s motto since the early 2000s is ‘You train the way you fight,’" he said. “It has been a step-by-step process for them to get there, and I still don’t think they are there.”
He notes that the aircraft are most likely flying from China’s Southern and Eastern Theater Command areas, which follow the country’s coastline from its border with Vietnam to the northern edge of Jiangsu province. The Y-8 maritime surveillance aircraft typically are based around Shanghai.
In June, China’s Air Force News carried an opinion piece noting that pilot training needed to improve. ADIZ flights can aid training by giving the units involved more experience, but their high tempo can also take a toll, leading to accidents and equipment damage. Allen said the PLAAF’s annual training cycle is at its peak at this time of year.
China’s Taiwan Affairs Office called its military activities around the island “just” moves to protect peace and stability, and again blamed Taiwan’s “collusion” with foreign forces - a veiled reference to the United States - for sowing tensions.
In Taiwan, defense officials do not see the sharp increase in the number of flights as a sign that China has improved its ability to sustain such operations. The ADIZ incursions also give Taiwan a chance to gather intelligence on Chinese aircraft and activities.
“The military has been getting experience about engaging the enemy on the verge of war, vigorously forging their reactions and counter-measures. Navy and air force officers are getting more and more familiar with what to do, and are able to coolly handle the Chinese Communists’ provocations,” said Ma Cheng-kun, director of the Graduate Institute of China Military Affairs Studies at Taiwan’s National Defence University.
Taiwan’s defence minister, Chiu Kuo-cheng, told a parliament committee that China’s limited midair refueling capability means its land-based fighter aircraft cannot operate far from the mainland.
According to data from Taiwan’s government, the majority of the flights are surveillance or anti-submarine aircraft - Y-8s and Y-9s - operating alongside fighters such as J-16s and J-10s. About 50 H-6 nuclear capable bombers have flown on the ADIZ-probing missions as well, as have KJ-500 airborne early warning and control aircraft.
Ma added that China was not likely to be able to sustain large-scale missions such as those earlier this month over a long period.
“They are limited by the maximum support limit of their relevant logistics departments and air combat management to sustain such high-intensity operations,” he said.
And although Taiwan has curtailed interception flights, other elements of the military - such as radar operators and intelligence officers - are getting valuable experience, he added.
“The defensive battle skills they display has meant the Chinese Communists are not likely to easily go to war and will only undertake ‘grey zone activities’ in their intrusions and harassment,” Ma said.