How do I know if someone's iPhone is in Airplane Mode or out of service?
How can you tell the difference between when someone is out of service and when their phone is in airplane mode ?
[Re-Titled by Moderator]
Question marked as
If you are asking how you can tell when you call someone if
their iPhone is in Airplane Mode or out of service, you cannot.
If your call does not go through, unless their wireless service
provides an error message, you will not be able to determine
from your phone what caused the failure to connect.
If you have physical access to that iPhone and it is unlocked, then
you would be able to tell if Airplane Mode was on.