Dalia flies an ultralight plane with a tailwind to a nearby town in 1/3 of an hour. On the return trip, she travels the same distance in 3/5 of an hour. What is the average rate of speed of the wind and the average rate of speed of the plane? Initial trip: Return trip: Let x be the average airspeed of the plane. Let y be the average wind speed. Initial trip: 18 = (x + y) Return trip: 18 = (x – y) Dalia had an average airspeed of miles per hour. The average wind speed was -3 miles per hour.