Master Sergeant William V. Bierd was a Marine veteran of World War II, China, Korea, and Vietnam. Besides playing Sgt Gabreski, Bierd was an uncredited
technical advisor on the film as well as a technical advisor on Marine Corps uniforms to
Gomer Pyle USMC. The US Marine Corps allowed Zens to film
amphibious landing exercises at
Camp Pendleton that appeared at the start of the film. A Marine Corps
HUS-1 helicopter was provided for the climax. Toward the end of the movie, a radio operator said, "Loud and Clear, Miss Muffet, hold one", played by Gregory S. Morrison, a Marine Corps Private Second Class, from Camp Pendleton (Note: The USMC does not have a Private Second Class. It should read Private First Class). When the movie played at the Northgate movie theater, adjacent to Texas A&M University, the marquee read "To the Shores of Hell - STARRING Gregory S. Morrison". ==References==