Operating an aircraft forced a submarine to remain surfaced while the machine was launched or recovered, temporarily surrendering the boat's defining advantage of concealment. Japan's I-400 concept resembles an early guided-missile submarine because its aircraft delivered long-range strikes, while Britain tried to use an aircraft for cruiser-style reconnaissance. HMS M2's Parnall Peto might find a target, but the submarine then had to travel faster on the surface, overtake the contact, dive ahead of it, and regain a firing position. That sequence was too slow and exposed for effective sea control. Aircraft handling also created the practical possibility that the scout could not relocate its hidden carrier. A payload that increased reach could still make the submarine less useful when it conflicted with the platform's core operating method.
Notable Point · 1:40:47-1:46:20
Why submarine aircraft carriers gave up their key advantage
Carrying an aircraft could extend a submarine's reach, but launching and recovering it forced the boat to remain visible when concealment mattered most.