| Answer | Crossword Clue |
|---|---|
| NEON | Gas that's lighter than air |
| AEROSTAT | Lighter-than-air aircraft |
| DIRIGIBLE | It's lighter than air |
| DIRIGIBLE | Lighter-than-air aircraft |
| DIRIGIBLES | Lighter-than-air craft |
| AMMONIA | It's lighter than air |
| AEROSTAT | Lighter-than-air craft |
| AEROSTAT | Any lighter-than-air craft. |
| BALLOONPARK | Place to take off in lighter-than-air craft? |
