Requirements:

Craft 12 Landing Gear
Collect 45 Flying Lessons

Flyin' Machine, Caretaker Boost, 4 Air Ferns
Notes: Landing Gear is Crafted. Flying Lessons drop from Fresh Grass.
Each Gear requires 9 Spring Posts (Compost Pile), 9 Puffy Tires (Wall Post) and 6 Another Bouncy Wheels (Direct Request)