Last week, the US Patent and Trademark Office granted Boeing patent rights for its midair refueling system designed for drones, Business Insider reported.

Theoretically speaking, with Boeing's drone refueling system, drones will fly forever without landing. In actuality, however, the drones will have to land periodically for maintenance. 

The refueling system is an exciting undertaking if Boeing decided to put its theory to the test. Also the midair refueling system can be efficient and effective way to manage and charge a fleet of drones.

At the moment, drones are limited in range and eventually they will have to land to refuel or recharge. The midair refueling system - if it becomes a reality - will work as follows: drones in midair will deploy self-flying battery-powered drones with retractable tethers that can connect to ground based power sources to refuel or recharge its system. And as soon as the drones are refueled, it can immediately fly off to complete designated mission, while the next batch of drones flies in and take their places at the power sources.

Drones' landing gears may be heavy but with this patent, it can be replaced with a tether that hooks onto a charging station, and this will help increase fuel efficiency, said GreekWire.

The Boeing's midair refueling system is so flexible that it can be installed according to specific requirements. The drones' tethers can be connected to land or ocean vessels; it can also be connected to moving vehicles, while the drones hover above the power source.

The patent for the midair refueling system was applied by Boeing back in March of 2013 and was approved by the US Patent and Trademark Office only last week. At the moment, Boeing's drone refueling system is sketched in paper but it seems too exciting and useful not to make this come to life, said Mashable.

It also said the system would be especially useful for drone delivery services, if they ever take off.