British aerial torpedoes also carried working magnetic detonators

Did British 18-inch air-dropped torpedoes have working magnetic detonators?

Yes. The aerial 18-inch weapons had working magnetic detonators as well as the larger ship and submarine torpedoes.

The working British magnetic system was not limited to surface-launched or submarine-launched 21-inch weapons. The 18-inch air-dropped torpedoes also used functioning magnetic detonators. Aerial release imposed its own entry and stability demands. British torpedo reliability therefore extended across several launch platforms.