They will continue until they reach their targets.
4 seconds sound clip from the Dr. Strangelove movie soundboard.
You can hear this line at 00:27:12 in the Blu-ray version of the movie.
Quote context
[...]
- And escape retaliation because of lack of proper command and control.
- Well, no, sir, I'm afraid not.
- You see, the planes were holding at their fail-safe points when the go code was issued.
- Now, once they fly beyond fail-safe, they do not require a second order to proceed.
- They will continue until they reach their targets.
- Then why haven't you radioed the planes countermanding the go code?
- Well, I'm afraid we're unable to communicate with any of the aircraft.
- Why?
[...]