Can you control a RC helicopter with another RC helicopter remote?

In general, you cannot control one RC helicopter with another RC helicopter's remote, as each remote is typically designed to communicate with a specific receiver in its corresponding helicopter. Remote control systems operate on specific frequencies and protocols, making them incompatible with each other. However, if both helicopters are designed to operate on the same frequency and use compatible protocols, it might be possible to control one with the other, but this is rare and not the intended use of the devices.