A submarine's last-ditch missile against helicopters

How would a submarine use a surface-to-air missile?

As a last-ditch weapon against a nearby ASW helicopter, followed immediately by an attempt to dive and escape.

Some Russian submarines carry air-defence missiles in the sail for emergencies involving nearby anti-submarine helicopters. A helicopter close enough to threaten the boat provides the immediate target. The intended sequence is to attack the helicopter, dive, and escape. This is a last-ditch survival measure for a submarine already in danger.