In the episode where the soldiers take leave in Hawaii we see them walk to their plane at the end with a UH-60 Blackhawk helicopter sitting behind them. But this aircraft would not exist until the mid-1970s
In the pilot episode, with a background of 1967, all of the characters wear helmets with helmet covers issued in 1970s.
In all the episodes of 1st and 2nd season, quite a few characters (Taylor, Johnson, Purcell) wear helmets with chinstraps from 1970s.
Tan Son Nhut air base, the base camp for the second season, is depicted as a relatively quiet location set among woods and hills. In fact, it was - then as now - Saigon's international airport, and one of the busiest airbases in the world at the time. It is located in a heavily built-up area, with neither woods nor hills.
Correction: Similar name - two different places: Tan Son Nhut Air Base Tan Son Nhat International_Airport
The airbase is in open country surrounded by trees and hills.
Correction: Similar name - two different places: Tan Son Nhut Air Base Tan Son Nhat International_Airport
The airbase is in open country surrounded by trees and hills.
When using smoke grenades for signaling and marking locations on the ground, the signaler "pops smoke", but does not identify the color of the smoke. The receiver of the signal identifies the color, and that color is confirmed by the smoke popper. Routinely, the platoon uses smoke and identifies the color at the same time.