THEATER OF OPERATIONS

North of the DMZ, the sky was cut into seven numbered boxes — Route Package One through Six Bravo — each one assigned to a single service to keep Navy and Air Force strikes from colliding over the same ridgeline. RP6, wrapped around Hanoi and Haiphong, held the densest air defenses of the entire war.

South of the DMZ, the same sky answered to a different map: four Corps Tactical Zones, I through IV, running north to south down the length of South Vietnam. Ground command drove that division — each zone tied to an army corps responsible for the war on the ground beneath it.

In this reconstruction, every sector carries its own radio net. Tune in on the frequencies below to talk the way the crews did — sector to sector, call sign to call sign.