Choir voices (Abbr.), 4 letters
Cockpit data: Abbr., 4 letters
Cockpit readings: Abbr., 4 letters
Cockpit stats: Abbr., 4 letters
Computer keys: Abbr., 4 letters
Contingencies: abbr., 4 letters
Control tower data: abbr., 4 letters
Fliers' concerns: Abbr., 4 letters
In-flight announcement nos., 4 letters
Model Carol's family, 4 letters