when client (iphone 6p) change fly mode ,there is no disconnect event

[xhacker5000]

when client (iphone 6p) change fly mode ,there is no disconnect event
How to catch the client disconnect event when I change the fly mode, the close event not be called.

any solutions ?

[lotas]

I think this is the same as #686 and #353

[lpinca]

There are cases where the only way to detect that a connection has been closed is via a heartbeat system which can be implemented, for example, by sending pings.