Adding lights on your RC Aircraft is a great way to add a more realistic look as well as to find it during dark nights. Thankfully light emitting diodes (LED) make this endeavor relatively simple with just some simple soldering. You can even select the color of the LED light that you want so you can replicate the traffic lights on real airplanes. As a bonus, LED light draw very little power so you will not compromise your RC airplanes operating range.
Remove the batteries from your RC airplane. The exact method will differ depending upon the make and model, especially if you built it yourself. Usually the battery compartment is near the center to preserve the center of gravity and it is secured behind a plastic panel with a Philips-head screw.
Snip the wires running next to the hole. Strip half an inch from either side of the cut in the wire. Twist the wires coming from the LED light to either stripped wire. Solder on just a dab of solder to ensure a good connection. Wrap the solder point in electrical tape until the raw metal wire is no longer visible. Do not wrap the wire together as that will short the circuit.