An airborne lookout before radar

The Blackburn Blackburn worked as a practical precursor to airborne early warning. A high-flying crew could see beyond a shipboard lookout's horizon, track an incoming formation, and report its direction to the carrier. Moving detection from roughly ten miles to thirty or fifty miles could turn five minutes of warning into fifteen or twenty-five. That extra time made it far more plausible to alert, launch, and direct fighters before attackers reached the fleet.