Depends of course on the helo staying (reasonably) still.

Or even just not maneuvering very much (e.g., could be traveling in a
straight line). Attack from the sun to limit visual warning, and the
helicopter would only have a few seconds (at best) to evade the bomb. Any
way you look at it, I'd hate to be in a helicopter vs. a fixed wing,
high-performance jet.

Tony