Frozen was loosely based on the fairy tale "The Snow Queen".

"Only 15% of CAS missions these days are flown by A-10s. The remaining 85% are flown by F-15Es, F-16s, F/A-18s, AV-8s, B-52s and B-1Bs using ROVER and AH-64s and AH-1s."

In "Letters of Transit" one of the observer said "shoot first I'll read them later" so the observer have the ability to read minds after a person is dead.