One day Chief Warrant Officer Walters of the 99th Assault Helicopter Company would complain that the Tet Offensive began a month early for him. But on New Year’s Day, 1968, the company’s gun platoon, known as the Headhunters, was still basking in a lull that had begun a couple of weeks before Christmas. No one had been killed or wounded. Not a single rocket or mortar had exploded in Nui Binh Base Camp. Only one helicopter had been hit by ground fire. On New Year’s, the Headhunters returned to the base camp shortly before lunch after a long-planned combat assault was called off. Then they were given a rare afternoon off. Led by Walters, the gunship pilots decided to visit a Filipino engineering battalion stationed in Nui Binh. After lunch, most of the Headhunter enlisted…