Mr Graetz, a pilot with 12 years' experience, founded Aerolane with Gur Kimchi, a veteran of Amazon's drone delivery project, on the basis that "there has got to be a better way to get more out of existing aircraft". The project has raised eyebrows among experienced pilots. Flying large gliders in commercial airspace means meeting strict flight safety regulations. For instance, the towing aircraft has to be confident it can release the tow line at any point in the flight, safe in the knowledge that the auto-piloted glider can make it down to a runway without dropping on top of the local population. Aerolane says a small electric motor driving a propeller will act as a safety net on their cargo gliders, giving them enough juice to go around again if a landing looks wrong or to divert to another location close by.