Search for “GTA SA Android save after Learning to Fly” (recommended: gtasaves.com or reliable gaming forums). Look for a file named GTASAsf1.b (this corresponds to save slot 1). The save should place you in the Desert airstrip with pilot school passed.
Because passing this mission is mandatory to progress the story (specifically to unlock the missions in Las Venturas), it is a common point where players get stuck. gta san andreas mission learning to fly save file android