More often, UAVs were defeated by the immaturity of the available technology, changing needs, soaring costs and, above all, the successful development of rival technologies.Pilots wantedFor decades a human pilot's eyes, sense of balance and hands were simply the best way to guide a flying machine, stay on course and cope with problems.
While most of the drones, also known as UAVs, are small some are more substantial and carry cameras.
More than 100 people have protested outside a site where unmanned aerial vehicles (UAVs) are tested.
These UAVs are getting much better, and much smaller".
UAVs are becoming a business sector with the greatest potential.
Luckily, replacement parts are cheap, and like many young technologies, UAVs are improving rapidly.
Disaster management is another sector in which UAVs are playing a part.
UAVs are still a relatively new technology, prone to glitches and failures.
We do know smaller, weaponized UAVs are in the cards.
"The civilian and commercial potential of UAVs is being realised more and more now", says Tony Dodd, of the Institute of Engineering and Technology.
