You can't always spot a muslim, because they are not always arabs. Iran
got many persians and descendants of mongols, wich are not arabs but are
muslims.

The answer to stop terrorist attacks with planes, withoiut segretaion may
be:

PIGS!!!

If muslims come in contact with or eat pig blood or flesh they will not
come to paradise according to themselves. That may not apply to everyone
as some have recently converted and don't know much about islam. But it
wil apply to most muslim fundamentalists.

Have containers with pig blood and flesh stored on every plane, close to
passengers. If the plane is exploding the passengers will be contaminated
with the pig flesh and blood, and preventing good muslims from entering
the paradise but sent to hell instead. Who want to be a terrorist if they
can't become martyrs and go to their paradise?

If this was done and some mullahs impose a fatwa that tells tha martyrs
can come in contact with pigs upon death then they also agree to change
their religion wich is not allowed. If they change their views about their
religion then there are hope for the future.