Roger Moore fights with Richard Kiel, as Jaws, who bites through a board in a scene from the film “The Spy Who Loved Me”, 1977. (Photo by United Artist/Getty Images)

A lunar eclipse appears behind a gargoyle atop the old red Dallas County Courthouse early Wednesday morning, October 8, 2014. The moon appears orange or red, the result of sunlight scattering off Earth's atmosphere. This is known as the blood moon. (Photo by Tom Fox/AP Photo/The Dallas Morning News)

A hot air balloon flies close to the ground in the Jezreel Valley in northern Israel during an international hot air balloon festival October 14, 2014. (Photo by Nir Elias/Reuters)

This photo released by North Korea's official Korean Central News Agency (KCNA) on June 7, 2012 shows North Korean leader Kim Jong-Un (C) surrounded by members of the Korean Children's Union (KCU) organizations during a joint national meeting to celebrate the 66th anniversary of the KCU organizations at Kim Il-Sung Stadium in Pyongyang on June 6, 2012. (Photo by AFP Photo/KCNA via KNS)

Mechanics work in the Buggy belonging to Argentina's Manuel Sisterna and Adrian Echegaray during technical verification ahead of the Dakar Rally 2015 in Buenos Aires January 1, 2015. (Photo by Enrique Marcarian/Reuters)

Masooma Alizada (L) and Frozan Rasooli (R), members of Afghanistan's Women's National Cycling Team prepare a bicycle before training on the outskirts of Kabul February 20, 2015. Afghanistan's Women's National Cycling Team has been breaking new ground for women's sports and pushing the boundaries of what is – and is not – acceptable for young women in the conservative Muslim country. (Photo by Mohammad Ismail/Reuters)

In the spring of 1965, within weeks of 3,500 American Marines arriving in Vietnam, a 39-year-old Briton named Larry Burrows began work on a feature for LIFE magazine, chronicling the day-to-day experience of U.S. troops on the ground – and in the air – in the midst of the rapidly widening war. The photographs in this gallery focus on a calamitous March 31, 1965, helicopter mission; Burrows’ “report from Da Nang”, featuring his pictures and his personal account of the harrowing operation, was published two weeks later as a now-famous cover story in the April 16, 1965, issue of LIFE.

Photo: Man your battle stations: The crew chief of helicopter Yankee Papa 13, lance corporal James C. Farley, mans an M-60 machine gun during a mission near Da Nang, Vietnam on March 31, 1965. (Photo by Larry Burrows/Time & Life Pictures)

Sergeant Andrew Garrett watches K-Dog, a bottlenose dolphin attached to Commander Task Unit 55.4.3, leap out of the water while training near the USS Gunston Hall March 18, 2003 in the Persian Gulf. (Photo by U.S. Navy/Getty Images)