No — Chesley "Sully" Sullenberger III is not exclusively left-handed; he is considered mixed-handed.

Chesley "Sully" Sullenberger III is an American retired airline pilot, diplomat, and aviation safety expert. He is best known for his role as pilot in command of US Airways Flight 1549, which he successfully landed on the Hudson River in January 2009 after a bird strike disabled both engines. This event became known as the "Miracle on the Hudson."

Sullenberger joined US Airways in 1980, accumulating over 20,000 flight hours throughout his career. Prior to his airline career, he served as a fighter pilot in the United States Air Force from 1973 to 1980. He was also an air safety investigator and accident reconstructionist.

After his heroic landing, Sullenberger became a public advocate for aviation safety. He co-authored a memoir, 'Highest Duty: My Search for What Really Matters,' which was later adapted into the 2016 feature film 'Sully,' starring Tom Hanks.

From 2021 to 2022, Sullenberger served as the U.S. Ambassador to the International Civil Aviation Organization (ICAO), appointed by President Joe Biden. He continues to speak on leadership, safety, and resilience.