Nance was born in Dallas, Texas. He was commissioned a Second Lieutenant in the United States Air Force and after pilot training served in both Vietnam, and as a Lieutenant Colonel with the Air Force Reserves, was called to active duty in Operation Desert Storm in Iraq. Concurrent with leaving extended active duty in 1975, he joined Braniff International Airlines as a pilot, and after the demise of Braniff, joined (and subsequently early-retired from) Seattle-based Alaska Airlines. Nance has amassed over 13,000 hours in his military, airline, and civilian flying careers.

After working his way through college with the ABC affiliate WFAA-AM-FM-TV in Dallas as a radio and television newsman, and following active U.S. Air Force duty as a pilot during Vietnam, in the 1990s he joined ABC News as aviation editor for Good Morning America and Aerospace Analyst for ABC World News from 1995 to the present. Nance has also appeared as a national aviation commentator on over 1300 radio and television shows, including The MacNeil–Lehrer Report, Oprah and Larry King Live.

A New York Times bestselling, award winning author, two of Nance's nineteen books, Pandora's Clock and Medusa's Child, were adapted and aired as two four-hour television miniseries for NBC and ABC, respectively. His latest novel, ORBIT (Simon and Shuster, New York, 2006), is currently under development as a motion picture from Fox 2000.

Nance holds both Bachelor of Arts and Juris Doctor degrees from Southern Methodist University and SMU Dedman School of Law.In 2003 he was named a Distinguished Alumni of Southern Methodist University, and in 2009 he was installed as a Distinguished Alumni of the Dedman School of Law at SMU.

Nance lives in Friday Harbor, Washington.