What is the maximum permitted transmitter output power when operating a model craft by telecommand?

FCC Part 97.215 specifically governs the telecommand of model craft, such as RC airplanes or drones, using amateur radio frequencies. To prevent excessive interference to other amateur operations while still providing enough range for safe control of the model, the maximum transmitter output power is strictly limited to 1 watt. Higher power levels, such as 5 watts (typical of a handheld transceiver) or 100 watts (typical of an HF base station), are unnecessary for line-of-sight model control and would needlessly increase the risk of interfering with other communications on shared amateur bands.