China has issued a notice to shut down portions of its offshore airspace for 40 days. The decision places temporary restrictions on flight activity across designated maritime zones, effectively limiting access to key stretches of airspace.
The alerts are in effect from March 27 through May 6, according to a report in The Wall Street Journal. Such a prolonged closure is uncommon and is expected to influence military aviation patterns in the region. Civil aviation seems unaffected, but flights need coordination to pass through these areas.
Formally called "Notice to Air Missions" or NOTAMs, these notices are generally used to alert pilots and aviation authorities to temporary airspace hazards or restrictions. However, this time, no official reason or explanation has been shared regarding the decision, which has sparked a new aviation mystery after military flights around Taiwan were suddenly stopped.
Ray Powell, director of the SeaLight project at Stanford University, which tracks Chinese maritime activity, said, "What makes this especially notable is the combination of SFC-UNL with an extraordinary 40-day duration—and no announced exercise. That suggests not a discrete exercise but a sustained operational readiness posture—and one that China apparently doesn't feel the need to explain.”
He added, "If the zones are confirmed to be linked to exercises, the warnings would represent a meaningful shift in how Beijing uses airspace control as a tool of military signalling."
China has reserved airspace zones covering an area larger than Taiwan's main island, including offshore areas north and south of Shanghai. These zones extend from the Yellow Sea off South Korea to the East China Sea off Japan. Some of China's past military drills have aimed to control routes the US military might use in a potential Taiwan conflict.
"The reserved airspace could provide an opportunity to practice the kinds of air combat manoeuvres that would be required in such a scenario,” said Christopher Sharman, director of the US Naval War College's China Maritime Studies Institute.
According to a senior Taiwan security official, China is taking advantage of the US being preoccupied with the Middle East conflict to boost its military presence. The current reservation of zones is “clearly aimed at Japan,” as the goal is to discourage US allies and undermine American influence in the Indo-Pacific region, the official said.
