It wasn't just fuel tanks. In 1995 I spent my honeymoon in Vietnam. Yes that's right Vietnam vets. In Saigon or Ho Chi Minh City as they call it. I regularly heard the blap blap of Hueys over the city it was so evocative. Say what you want but the Vietnamese knew a good chopper when they heard it. More than that, it was clear they didn't like the Chinese and preferred the Americans Rather ironic that.