Yes, the Hornet rechargeable electric air horn has no compressed gas so it can be transported safely on an airplane. Traditional disposable compressed gas air horns are prohibited in both carry-on and checked luggage on passenger airplanes. In addition, they cannot be shipped air freight as they are classified as hazardous goods.
No. Current regulations prohibit the transport of compressed gas cylinders on airplanes, and bear spray is categorized as such. The Hornet rechargeable battery powered air horn, however, can be safely transported on airplanes.