往おう復ふく航こう空くう券けん

• 片かた道みち航こう空くう券けん

  片道航空券 is a one-way air ticket, while 往復航空券 covers both directions.

• 往おう復ふく切きっ符ぷ

  往復切符 is a general round-trip ticket (often for trains), whereas 往復航空券 specifically refers to air travel.

Compound of 往復 (round trip) + 航空券 (air ticket).