It will not involve any kind of airbags in this particular patent, but rather, it will engage the sensors that are integrated within the handset itself, such as the accelerometer and magnetometer among others, so that this particular failsafe system, so to speak, will be able to determine the side and point of impact in a jiffy. Following that, there will be a dedicated processor that calculates the required adjustment for a fraction of a second, as it engages a motor with eccentric mass so that it can adjust the handset’s position mid-air, letting it land on its least breakable side.
Another recent patent involving Apple would be its iDevices being turned into smoke detectors, just in case you’re interested.