Model aircraft airbags

When learning to fly a radio-controlled aircraft, you will likely crash quite a bit, which can damage your model. They're generally easy to repair, but what if you didn't need to?

I suggest adding a simple airbag to be activated immediately before crashing. It would be just a simple lightweight plastic bag packed into a compartment at a strategic location on the airframe, connected to, say, a 12-gram CO2 cartridge, with a solenoid valve in between. Many model aircraft are easily capable of carrying such a mass. When a crash is imminent, it inflates, cushioning both the aircraft and whatever it collides with.

On an airplane with a pusher propeller, the setup is easy: just put it in the nose. With a tractor configuration, it would be more difficult and would have to be up to the designer/builder of the plane. Maybe the motor could retract, or the airbag could be reinforced against propeller damage, or it could expand around the propeller. Helicopters and multicopters are more difficult still—perhaps detach the rotor(s) immediately prior to airbag deployment? And the airbag would need to cover all sides of a helicopter/multicopter, because they're far more likely than airplanes to crash in random orientations and directions.

Deployment could be manual via a button or switch on the transmitter, and/or triggered by proximity sensors on the model, to detect uncontrolled (i.e. not a deliberate landing) approach to obstacles or terrain.

Could also act as a flotation device in case of a crash into water, if your aircraft isn't buoyant enough on its own, triggered by water contact.