From Wikipedia:
https://en.wikipedia.org/wiki/Boeing_AH-64_Apache
“The crew compartment and rotor blades are designed to sustain a hit from 23mm rounds. The airframe includes some 2,500 lb (1,100 kg) of protection and has a self-sealing fuel system to protect against ballistic projectiles.
The crew compartment also incorporates a transparent blast shield between the pilot and gunner seats so that at least one crew member can survive in the event of a direct hit, but the canopy and windows are otherwise unrated against ballistic threats.”
Apache is built tough but the big problem would be them having to come down on water. They can't parachute to safety and even autorotate is a controlled crash.