The PRC is keen to advertise its airborne early warning and control capability at the moment. Perhaps they’d like both the Koreans and any other possible visitors to know there is no sneaking into Chinese airspace as things get tense over the Peninsula.
So today’s People’s Daily has this piece about a successful 24 hour endurance exercise conducted by elements of the PLA Air Force. AEW&C aircraft maintained continuous coverage during the exercise period.
The exercise validated what the PLAAF is calling “all-time all-territory early warning combat
So no “navigation errors” or “accidental” transgressions, people. They’re watching.