What happens if a Japanese carrier suffers a major mechanical failure on the way to Pearl Harbor?
Short answerThe carrier and escorts must detach, reducing striking power enough that the whole force would probably return.
NotesA disabled carrier cannot simply remain with the formation because it would slow the post-strike withdrawal. Detaching it preserves the fleet's speed but requires escorts for the voyage home. The separation also removes a large portion of the air group from an operation whose striking power depends on concentrating six carriers. A serious turbine or propulsion failure would probably force the whole formation to turn back. One engineering casualty can unravel a tightly balanced carrier plan before combat begins.