China-based Quanum is offering a bomb system called “Bombs Away” for radio-controlled model airplanes that can be installed “in seconds” and fits most of the planes with engine size 0.25 or bigger out there. All that users need to do is to connect the bomb’s servo wire with a channel on the radio and then stick the bomb’s release pod to the airplane.
The bomb splits in half so that you can fill it with any payload you want. It can then be dropped in mid-air from your plane and be reused later as long as it stays undamaged. Quanum says an impact protector should protect the bomb, which is made of nylon, from the worst possible damage, for example when the bomb hits a rock.
The model is scaled at a proportion of 1:6, weighs 103g and is 23.5cm long. You can already buy the bomb on the web, for example here (price: $16.95).