Related Clues:

• Comms code for 'd'
• River area
• Co-founding SkyTeam airline
• Atlanta-based carrier
• Silty triangle
• Handed out cards, dropping a letter
• It's around the mouth
• Mississippi formation
• D, in Greece
• 'Keep climbing' sloganeer
• Deposit at a river's mouth
• Southwest competitor
• Daedalus started with this sort of wing
• Letter was primary in returning thanks
• Greek D