Yes, the rules are quite clear, but I remember that I asked the same question when I played the game my first time:
"You cannot send air units on “suicide runs”, deliberately moving them into combat with no place to land afterward. If there is any question about whether an attack is a “suicide run”, then in the combat move phase, you must declare, prior to rolling any battles, some possible way (however remote the possibility is) for all your attacking air units to land safely that turn. This could include a combination of combat moves. It could also include noncombat moves by a carrier. If it does include noncombat moves by a carrier, then the carrier may not move in the combat move phase.
In order to demonstrate that an air unit MAY have a safe landing zone, you may assume that all of your attacking rolls will be hits, and all defending rolls will be misses. You may NOT, however, use a planned retreat of any carrier to demonstrate a possible safe landing zone for any fighter.
If you declared that a carrier will move during the noncombat move phase to provide a safe landing zone for a fighter moved in the combat move phase, you must follow through and move the carrier to its planned location in the noncombat move phase unless the fighter has landed safely elsewhere or has been destroyed before then."