Related Clues:

• Terminal figs.
• Airport-board listings: Abbr.
• Brief guesses?
• Circumference-to-diameter ratios
• Circle figures
• Station info
• Platonic H's
• TV's Rockford et al.
• ''H'' look-alikes
• Weather may affect them: Abbr.
• LAX stats
• Certain Greek letters
• Zetas' followers
• Cockpit predictions
• Letters from Thessaly