China-Taiwan M503 Airway Dispute

China has cancelled all concessions previously made to Taiwan regarding the M503 airway that runs along the ZSHA/Shanghai and RCAA/Taipei FIR boundary.

What does this mean in practice?

China have moved the airway 6nm back towards the FIR boundary.
They have started allowing eastbound flights on the the W122 and W123 connecting routes.

So now, of all these routes, the only one that is not bi-directional is W121 (westbound only).

Taiwan aren’t happy, same argument as before: they say the airway is too close to existing routes that serve airports in outlying groups of Taiwan-controlled islands, and thus poses a risk to safety. China have ignored them.

Can I use M503?

China only allow airway M503 to be used under certain conditions:

Aircraft must be RNAV2 capable.
The flight must be going between VHHH/Hong Kong or VMMC/Macau and certain Chinese airports: ZSPD/Shanghai Pudong, ZSQD/Qingdao, ZSYT/Yantai, ZYTL/Dalian.

Everything else transiting east-west across this region will need to use the congested parallel A470 airway along the southeastern coast of mainland China.

China-Taiwan M503 Airway Dispute