The observer navigated through darkness, identified what the aircraft was seeing, and gave the pilot a route home before the attack. He also doubled as rear gunner and supplied the spatial awareness that later electronic systems would provide. A second crew member was a capability rather than dead weight in 1930s naval aviation. The same long-range requirement helps explain the Fleet Air Arm's interest in two-seat fighters such as the Fulmar.
Notable Point · 30:14-34:52
Why the Swordfish needed a navigator
A two-person Swordfish crew divided navigation, target recognition, and flying tasks that later aircraft systems could absorb.