Related Clues:

• 7th Greek letter
• Symbol for viscosity
• Metal core?
• In-flight info
• In-flight announcement
• When a plane is due in: Abbr.
• H, in Greece
• Homeric H
• Globe line: Abbr.
• H look-alike
• Useful info at Dulles
• Seventh Greek letter
• Airport guesstimate
• Pilot's info, briefly
• Platonic letter