ΔE 6.3, close: similar, with a visible difference side by side. Light Blue RLM78 is more muted, cooler than Aircraft Gray.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Light Blue RLM78 is more muted, cooler than Aircraft Gray.
The same difference applies the other way round: Aircraft Gray is more saturated, warmer.
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 Aircraft Gray on the colour wheel See Light Blue RLM78 on the colour wheel
All matches: Aircraft Gray equivalents · Light Blue RLM78 equivalents