All pre-Nomad (barely):
Avengers v.1 #125: Cap's cleared of murder charges and Iron Man can't stop touching him.
Avengers v.1 #126: When Thor gets upset about Cap's brooding, Iron Man tells him that Cap's been hurt worse than the whole country.
Giant-Size Avengers #1: The earliest hug-and-fly?. (This is immediately after Avengers #126.)

Post-Nomad (Finally!!):
Avengers v.1 #131: Tony thinks Steve's new Nomad costume looks great. (*still snickering at said costume*)