<text id=00he1910><title>Heavy Air Traffic Above Khe Sanh</title>
<history>US Air Force: Events History</history>
<article><hdr>Heavy Air Traffic Above Khe Sanh</hdr><body>
<p>The cargo carriers were a minority in the air traffic around Khe Sanh. During any typical day, there would be 350 tactical fighters hitting enemy positions, augmented by the carpet bombing of about 60 B-52s in from Guam. Thirty or so FACs would be working the strikes, marking targets and calling in specific aircraft. Ten or a dozen RF-4Cs would race low across the battlefield, cameras rolling. And all of these low-flying planes were working in among the invisible tracks of dozens of shells from enemy, Marine and Army artillery, each one capable of totally destroying an aircraft if it hit. At night, the AC-47 gunships came in, using their batteries of Miniguns to shatter the enemy. They also served as night FAC aircraft and battlefield illuminators.
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<p>Because of the weather, more than half of the strikes were directed by radar. The Marines had their own TPQ-10 working 20 hours a day and bringing ground support strikes as close as 150 ft (45 m) from their forward positions. The USAF used one of its Combat Skyspot MSQ-77 radars to direct the B-52 strikes.
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<p>All incoming tactical aircraft reported to the airborne battle command and control center, a C-130 in orbit above the area, and were then assigned to a specific FAC to work against his target array. The FAC brought in each individual strike; often aircraft were stacked in holding patterns up to 35,000 ft (10,700 m), waiting to be cleared down to drop their ordnance and get back home.
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<p>The B-52s worked their own way. They bombed by the Bugle Note procedure, a system that used a grid map of the area with lines subdividing it into plots 1 x 2 km (0.6 x 1.2 miles) in size. That box was the size of the bomb pattern from a cell of three B-52s. Every 90 minutes, on the average, three of the big bombers arrived at a specific point in the air, were picked up by the MSQ-77, given a route to the target box, and told when to drop their bombs. Late in the battle, the formations changed their timing and size to six every three hours. The effect was the same. Bombs generally were dropped to impact more than 3,000 ft (900 m) from friendly forces, but in an emergency, the B-52s demonstrated that 1,000 ft (300 m) was feasible, and made frequent attacks that close to Marine positions during the battle. Tactical strikes worked within a few hundred feet, generally.
