| Answer | Crossword Clue |
|---|---|
| triplanes | An early type of airplane with three pairs of wings, one above the other |
| biplanes | An early type of aircraft with two pairs of wings, one above the other |
| triplane | airplane with three supporting wings, one above another: a design used mainly in the early history of the airplane |
| biplane | airplane with two sets of wings, one above and usually slightly forward of the other |
