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.