[4] McDaniel was shot down while flying an A-6A Intruder aircraft (buno 152594) on 19 May 1967 during an Alpha strike on Văn Điển, south of Hanoi, in North Vietnam during Operation Rolling Thunder.

During that time McDaniel was detained in isolation for more than two weeks, severely beaten, bound with ropes resulting in a compound fracture of his arm, deprived of sleep and subjected to electrical shock.

He is the author of Scars and Stripes, a book telling about his six years of captivity in North Vietnam, with much of it in Hỏa Lò Prison, known as the Hanoi Hilton.

In this capacity, Captain McDaniel worked daily with Congress on national defense planning and provided legislators with information vital to the strategic development of Navy forces throughout the world.

[4][6] McDaniel subsequently became involved in the Vietnam War POW/MIA issue, leading to a "grassroots campaign to focus attention on American servicemen still missing in Southeast Asia.

"[6] In 1982, McDaniel ran on the Republican ticket against Democratic incumbent Charles Orville Whitley to represent North Carolina's 3rd congressional district.

In 1988, McDaniel went on a speaking tour of US Navy commands to encourage military personnel to register to vote and discussing his experiences as a POW.

Due to an unsuccessful escape attempt by two of his fellow prisoners, his captors launched a vicious round of torture to single out the senior POW's who were to blame for the breakout.

During these torture sessions a confession led to exposing him as the communications link between the senior ranking officer of the main prison camp and the adjacent annex detachment.

His exemplary courage, maximum resistance, and aggressiveness in the face of the enemy reflected great credit upon himself and upheld the highest traditions of the Naval Service and the United States Armed Forces.