Nothing! Everything you need to get flying is included in the box.
The E-flite® Apprentice® S 15e RTF airplane is the most intelligent RC airplane ever offered by Horizon Hobby. At its heart is groundbreaking SAFE™ (Sensor Assisted Flight Envelope) technology that makes RC flight incredibly easy, even for the least experienced user. Its combination of spatial awareness provides flight envelope protection which adds a degree of security never before available, while its smooth flight capability battles windy conditions so that all you feel is control that’s crisp and responsive. Multiple levels of flight envelope protection are provided that can be reduced or removed as your skills progress, yet the “panic” feature is always there to instantly return the model to level flight if you ever lose orientation.
Requiring just minutes to assemble, you’ll appreciate how its quiet brushless power system delivers outstanding performance with long, enjoyable flights. Plus it’s built to last from lightweight Z-Foam™ material that’s tough enough to handle everyday flying punishment without getting bent out of shape. After you’ve mastered the basics of flight, the Apprentice S is capable of performing a complement of aerobatic maneuvers such as loops, rolls, and even inverted flight. You can also turn the Apprentice S into a great floatplane by simply adding the specially designed E-flite Apprentice S Floats (EFLA550)—sold separately.