Enter a clue or pattern or both:
The Clue
Command level: Abbr. (3 letter answer)
The Answer
ECH
Tags
Notes
The answer ECH is rarely seen, appearing only about once every 1100 puzzles.
Related Clues
R.A.F. formation
Aircraft formation: Abbr.
Flight formation: Abbr.
Flying formation: Abbr.
Hierarchical level: Abbr.
Level of hierarchy: Abbr.