TWA Flight 541 was a domestic passenger flight hijacked in the United States by Robin Oswald in an attempt to free Garrett Brock Trapnell, who was a prisoner at the United States Penitentiary, Marion (USP Marion).

[2] On January 29, 1972, Garrett B. Trapnell hijacked a TWA plane flying from Los Angeles to New York.

He demanded $306,800 (equivalent to $2,234,734 in 2023), the release of the imprisoned Angela Davis, and a conversation with President Nixon.

[3] On May 24, 1978, Trapnell's friend, 43-year-old Barbara Ann Oswald, a US Army staff sergeant on leave, hijacked a Saint Louis based charter helicopter and forced the pilot to land in the yard at United States Penitentiary, Marion.

While landing the aircraft, the pilot, Vietnam War veteran Allen Barklage, struggled with Oswald and managed to wrestle the gun away from her.