Why Constellation needs hull-mounted sonar

Was it a mistake to omit hull-mounted sonar from the Constellation class?

Yes, because a towed array can be lost or damaged and the ship needs an independent backup sensor during operations.

A towed array offers important performance but remains an exposed system that can become unavailable. The ship can lose or damage it during operations. Hull-mounted sonar is much harder to lose because it remains protected within the hull. Keeping both sensors preserves an independent search capability when the primary array cannot be used.