The helicopters used to supply the soldiers are Sikorsky CH-34 Choctaws. Although it remained in US Army inventory until the late 1970s, almost none were used by the US Army in Vietnam. At the time the film is set, the primary US Army helicopter deployed in Vietnam was the dual rotor Paisecki H-21 Shawnee.
The US Marine Corps did operate CH-34s in Vietnam, but the first US Marine units arrived in country a year after the setting of the film. The military of the Republic of Vietnam also operated some Choctaws, but again after the time period in which the movie is set.
The US Marine Corps did operate CH-34s in Vietnam, but the first US Marine units arrived in country a year after the setting of the film. The military of the Republic of Vietnam also operated some Choctaws, but again after the time period in which the movie is set.
Major Barker tells his executive officer that he served in Korea during the Korean War, yet he wears no Combat Infantryman's Badge. He would have earned a CIB for his infantry service during that earlier war.
Burt Lancaster (Maj Barker) was about 64 years old when this movie was made. No real Army major would be able to stay in the service until that advanced age. He would have been retired at a much younger age as a result of being continually passed over for promotion, as Major Barker had been.
Many of the American soldiers, especially Corporal Coucey and the executive officer, have hair styles that are much longer than allowed by Army regulations.
The only US advisors who carry spare ammo pouches on their belts are those who are armed with M1911A1 pistols. Those who are equipped with M3 submachine guns (like Maj Barker) and M1/M2 carbines carry no extra ammo pouches.
None of the automatic or semi-automatic weapons eject any empty cartridge cases while being fired.
At the very beginning of the movie during the credits and the overview of the camp and right after the title shot, if you look in the far background at the top of the scene you can see what looks like traffic and cars passing by.
When Lt. Wattsberg walks into Major Barker's office to tell him that they got the air support they needed, Barker was reading a book called "Seven Firefights in Vietnam", which wasn't published until 1970.
During the beginning of the movie, when the XO is showing Major Barker a map of MukWa, a microphone boom briefly appears at the bottom between them.
Both Corporal Coucey and Corporal Lincoln salute Major Barker incorrectly when they report to him for duty. Instead of saluting, waiting for the major to return the salute, then dropping theirs, both men quickly drop their salutes before Barker even begins his.