Before I flew it was normal and when switching it on I would put in my password but now it doesn't need it. On switching on the screen shows Aircraft check and please confirm switch on - press okay.
If I understood your question correctly, you want your phone to stop asking if you want to continue in Aircraft mode. This happens every time you use Airtime mode and do not switch to a different profile. Just confirm that you want to use a different profile and confirmation for the use of Aircraft mode shouldn't happen the next time you switch your phone on.