This week, we review four different remote-control (RC) helicopters (there are so many more that we’ll be reviewing more in the not-too-distant future). Each is a little different, but they do have some things in common. To start with, you’re going to need a lot of batteries. In most cases, the remote control unit (not the actual helicopter) takes 6 AAs. The choppers themselves have rechargeable batteries that will give you 10-15 minutes of flight time between plugins. They also all have a built-in stabilizer (sometimes called a gyro) that, as one of the manufacturers put it, lets you focus on flying instead of on trying to keep it from crashing. Finally—and most importantly—they’re a fantastic way for dads and kids to have a ton of fun playing—and learning about the physics of flight—together.