While there is no doubt that the TBD Devastator was an obsolete airplane by 1942 (compared to its Japanese counterpart, the B5N "Kate"), its lack of success at Midway was not wholly due to its poor performance. The US torpedoes of that era (as used by submarines as well as torpedo bombers) were notoriously ineffective: running too deep, failing to run true, exploding too early, and failing to explode on contact. Apparently at least one torpedo struck a Japanese carrier at Midway without exploding - the torpedo broke apart, and surviving crewmen from the carrier even used the torp's air flask for flotation when they abandoned ship ! Even if all of the aircraft survive and return, a torpedo attack mission cannot be considered a success if the weapon doesn't explode when it strikes a ship.