In a skillet over medium heat, cook ground beef until browned, then drain excess fat.
Add taco seasoning and water to the beef, simmer for 3-4 minutes until thickened, then set aside.
Preheat air fryer to 375°F.
Fill each tortilla with 2 tablespoons of taco meat and a sprinkle of cheese, then fold in half.
Spray both sides of tacos lightly with cooking spray and place in air fryer basket standing up or in a taco rack.
Air fry for 6-8 minutes until tortillas are golden and crispy.
Remove carefully and top with tomatoes, lettuce, and sour cream before serving.