Can the S3306 metal gear servo be used in a giant scale airplane?

thanks,
Greg

The airplane size isn't the determining factor. It's the torque a surface requires. Here are the torque specs for the servo. You can use it anywhere these torque numbers are appropriate:

Torque: 267 oz-inch (19.2kg/cm) @ 4.8V
333 oz-inch (24.0kg/cm) @ 6.0V