Unless the current levels of battery capabilities have changed dramatically, most helicopter type drones last roughly 20 minutes in the air. That does not include military drone with an airplane body style, we are talking about helicopter type drones. Not only is there airtime limited by battery power, the elevation they can attain is also quite limited. That is why we balk when we see a report of a drone at extreme elevation for great lengths of time. It is just unlikely we or any other country have that technology currently. The FBI is now investigating what they consider to be a drone incident however we would beg to differ and believe it may be an unidentified flying object. This event happened near Davis Monthan Air Force Base and you can learn more about it below.