WASHINGTON/PARIS (Reuters) - Western militaries are experimenting with having future drone pilots command up to four aircraft at once, adding new potential challenges even as a top-secret U.S. drone's crash in Iran exposed the risks of flying unmanned aircraft thousands of miles away.
The initiative could help satisfy feverish demand for unmanned planes at a time when budgets are tight, and military officials said they see great promise in initial tests under way in Britain and the United States.
But they also acknowledge some hurdles, including public resistance, legal questions and added stress on pilots -- concerns heightened by news that U.S. authorities are investigating whether a combination of pilot error and mechanical failure caused the loss of the Lockheed RQ-170 Sentinel shown on Iranian television.
"If there was any pilot error in the recent loss of the drone over Iran, that will have to make policymakers think long and hard about entrusting the operation of multiple drones to one pilot at the same time," said Loren Thompson, a Virginia-based defense consultant.
"Any time a remote pilot's attention is divided between multiple aircraft, the likelihood of errors will increase," said Thompson, who advises companies including Lockheed Martin Corp, which built the stealthy batwing-shaped RQ-170 surveillance drone.
To save money and make unmanned aerial vehicles (UAVs) less reliant on massive ground support crews, weapons manufacturers are working with military officials to develop more autonomous control systems and improve networking among planes.
At the moment, it can take hundreds of support staff on the ground to run a single drone for 24 hours, adding cost and complications at a time when budget-cutters are looking for billions of dollars of program cuts.
But new high-tech networking systems and ground stations in development would let a single pilot fly four drones, possibly even from different manufacturers, dramatically reducing the ground staff now needed for each plane.
Early work on such systems has been going on for some time, but heavy demand for more drones and mounting budget pressures are now bringing them closer to operational use.
General Atomics, maker of the armed Predator and Reaper drones, is building a demonstrator ground station for the U.S. Air Force that allows one pilot to command four UAVs, said Christopher Ames, head of business development for the privately held San Diego-based company.
"That's a big deal in the era of tight budgets," Ames said. "It's a significant achievement."
Initial tests have also been done with one pilot managing two Northrop Grumman high-altitude Global Hawk spy planes as they changed guard, according to industry executives.
Britain and the United States are working on a joint program involving up to five armed drones, according to a source familiar with the effort.
The biggest players in the sector - Northrop, General Atomics, Textron Inc's AAI Corp, Raytheon, and to a lesser extent Boeing Co and Lockheed Martin Corp - will likely gain the most from the focus on upgrades, said Phil Finnegan of the Virginia-based Teal Group.
AeroVironment Inc, leading maker of small UAVs such as Raven and Puma, should also fare well, he said.
Experts say more multitasking is needed because there are simply not enough pilots and technicians to support the rising number of sorties. Long hours and inadequate staffing have pushed the Air Force's 350-odd drone pilots and their support crews to their limits.
The Air Force says it selects drone pilots who are well-adjusted individuals, have families and "good moral standing." Still, the job can entail pushing a button that results in someone's death half a world away. A recent study found drone pilots report symptoms of burnout and "clinical distress."
But the prospect of handing over full control to autonomous unmanned aircraft is still far from reality.
"Some people had predicted an end to the man in the loop. But the human aspect of UAV deployment is stronger than in the past," said a person familiar with the new initiative.
Most current drones are flown either manually from a desk, often thousands of miles away, or via parameters programmed before a flight that are then monitored by a remote pilot.
Now in development are systems that would allow the pilot to have a form of dialogue with more autonomous UAVs, allowing one person to juggle several missions.
"You might say search this area and find some tanks, then report back to me," said a person familiar with the efforts. In a process known as "non-learning autonomy," the UAV would ask if the pilot wants to attack, giving him or her the final say.
Planners are also toying with the idea of "self-learning autonomy" in which a drone could spot a target and launch an attack independently if certain conditions were met.
But ideas like these conjure up images of flying robots, armed and with minds of their own, and for now that is something most strategists and the public would balk at.
Even the more limited autonomy now under development could raise potential legal difficulties by blurring the rules of engagement that underpin military law. Without protection, operators could be held liable if something went wrong.
Designers must also overcome formidable obstacles in keeping communications intact as aircraft twist and turn to maneuver for battle or avoid other aerial threats. Most UAVs have to turn relatively sedately to avoid losing their satellite links.
But technology is not the main hurdle, said Ed Walby, director of business development for Global Hawk. He said civilian cargo planes could now be outfitted to fly remotely, if it were not for policy issues that need to be worked out with air traffic control and the American public.
Despite various concerns, experts clearly see growing demand for anything that extracts more value from existing drones - new sensors, radar systems and the ground stations that pull it all together, and networking systems.
"In today's budget environment, unmanned vehicles will only become more valuable, and everyone will be focused on getting more out of the systems while they're airborne," said Walby.
Editing by Warren Strobel and Mohammad Zargham