A pilot assigned to an aviation brigade of the air force under the PLA Southern Theater Command gives his regards to ground crews before taxiing out during a real-combat flight training exercise in mid September, 2020. (eng.chinamil.com.cn/Photo by Wang Guoyun)

The Chinese People's Liberation Army (PLA) is apparently continuing its combat-oriented exercises and combat readiness patrols in the Taiwan Straits, as it reportedly sent warplanes to the region again on Sunday, marking the fourth consecutive day since the start of the eight-day National Day and Mid-Autumn holiday period on Thursday. It also seems as if the PLA's sorties are wearing out the military on the Taiwan island, observers said on Sunday.

A PLA warplane, presumably a Y-8 anti-submarine warfare aircraft, again entered Taiwan's self-proclaimed southwestern "air defense identification zone" on Sunday morning, the Taipei-based newspaper the Liberty Times reported on the same day, citing local military enthusiasts who recorded open broadcasts by the island's armed forces to the PLA aircraft.

The sortie marks the fourth consecutive day the PLA has sent warplanes near the Taiwan island since the start of October, and the eight-day National Day and Mid-Autumn holiday period on the Chinese mainland, the report said.

According to the Twitter account of island of Taiwan's defense authority, it was able to identify two PLA Y-8 anti-submarine warfare aircraft in its southwestern "air defense identification zone" on Thursday and Saturday respectively. Military observers said the island's defense authority often does not disclose all PLA activities due to either its unwillingness to expose weaknesses, or inability to detect and identify the PLA warplanes.

The frequent PLA warplane sorties, which have even taken place on national holidays, demonstrate the PLA's capability and determination in safeguarding national sovereignty and territorial integrity, a Chinese mainland military expert, who asked not to be identified, told the Global Times on Sunday.

Beijing-based military expert Li Jie told the Global Times that by deploying reconnaissance aircraft, like the Y-8 anti-submarine warfare aircraft, the PLA has been increasing the intensity of patrols, as well as search and reconnaissance missions, in order to gain more intelligence, with the goal of providing basic information and creating advantageous conditions for its future maritime activities and combat operations.

The concentrated PLA operations also seem to be depleting the will of the military on the Taiwan island as they result in huge pressure being applied on the island's logistics support services, Chinese mainland analysts said.

Citing data released by island's defense authority, media on the island reported on Sunday that the Chinese mainland has conducted 51 warplane sorties in 16 days since mid-September. In response to the PLA's operations, the island has scrambled warplanes and spent more than NT$100 million ($3.46 million) in fuel expenses, maintenance, logistics support and stand-by costs, the report said.

Every aircraft has an expiry date, and they eventually go beyond repair, malfunction and need to be scraped, particularly when they are not well maintained, the expert said, noting that each time Taiwan scrambles its warplanes, they move one step closer to the junk yard.

The PLA already has significantly more aircraft than military on the island, and the mainland's defense industry can continuously build more aircraft at better quality, the expert said.

In addition to warplane sorties, the PLA also seemingly sent a warship to the waters off Hualien, a county off the east coast of Taiwan, on Friday, the Liberty Times reported on Sunday.