ΔE 14.8, fair: the same colour family, but not a straight swap. USAF Green is a little lighter, much more muted than Turquoise.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). USAF Green is a little lighter, much more muted than Turquoise.
The same difference applies the other way round: Turquoise is a little darker, much more saturated.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Turquoise on the colour wheel See USAF Green on the colour wheel
All matches: Turquoise equivalents · USAF Green equivalents