Air support for troops in the Vietnam War began with the latest and fastest jets of the 1960s. Whether they we land-based or carrier based, these jets could swoop in with bombs, missiles and guns. But then they were gone. High performance jets can't hang around. And they are not made to go slow.
F4 Phantoms would lower their landing gear on close-support missions to get their weapons on target.
The first solution to the problem was to go retro: The Douglas A4 Skyraider.
Developed during World War II, the Skyraider first flew in March 1945. The war ended before it could be deployed in significant numbers. By 1967 the design was far out date in the jet world, but the A4 could fly for more than six hours with its basic fuel load.
The single-engine propellor-driven aircraft carried four 20mm cannons with 200 rounds of ammo for each gun and could carry 8,000 pounds of bombs, rockets and any other ordnance that could be hung on its wide wings. In a ground support role, the Skyraider could attack a target and wait in the area to see and respond to the enemy's next move.
In the same way, the C130 Hercules can stay over the target area carrying tons of ammo for miniguns and cannons up to and including a 105mm howitzer. The newest model reported in Task and Purpose now has a laser capable of disabling trucks.
This four-engine tortoise in a world of supersonic hares can loiter of hours over a battle supporting the troops on the ground long after jets have sped away.