Just a few thoughts...
Is it possible to not activate torpedo until water level interaction?

This may solve torpedo homing issue...
Also, 250 feet altitude seems very high. Without drag parachute, torpedo would dive
very deep.
Maybe making dummy torpedo model that stays at water surface at all times following directly below launch aircraft not visible.
Like what GWX team did for the Humpback Whale model.
That way, the torpedo dropped from Aircraft is just for sim. Real torpedo is fired from dummy model at water surface when dropped torpedo dummy interact with water.
Maybe "
Splashes in the Water" Sonar Station report sound would be nice as well?

Currently, Sonar Station does not report enemy torpedo's and if you are submerged and aircraft drops a torpedo you currently have
NO warnings.