Computer Co-pilots 'Smarter' UAVs Could Prevent Human Error During Landings

The answers are said to be coming for all those U.S. Air Force UAV crashes: stouter, smarter airplanes that would be controlled by computers during takeoffs and, most importantly, landings, when the craft are hardest to control.

In the meantime, the Air Force is about to field a laser altimeter that could make its Predators and Reapers easier to fly until that automated takeoff-and-landing system is ready for the Reapers in 2012. The Reapers are scheduled to take over completely for the Predators in 2016.

For now, personnel inside launch and recovery stations overseas continue to guide the Predators and Reapers in with joysticks at the end of each mission. These operators are given control of the aircraft after pilots and sensor operators at bases in the United States are done taking videos or striking targets with Hellfire missiles. Local teams must land the planes because the signal delay from the United States would make them all but impossible to control.

A total of 65 Predators have crashed, including three so far this year. Thirty-six of the crashes were attributed to human error, and about half of those occurred during landing, according to Air Force records.

The issue of human error came to the fore in 2008, when then-Lt. Col. Robert Herz, a researcher at the Air Force Research Laboratory, reported that 71 percent of Predator crashes between 2003 and 2006 resulted from human error.

Despite the crashes, yesterday isn't fast enough for those who want a cloud of video-equipped UAVs over Afghanistan. The Predators and Reapers are such tricky aircraft to fly that the Air Force counsels patience as delicately as it can when Defense Secretary Robert Gates demands more and more planes in the air to support ground troops.

"It's been difficult to keep up with the demand and to do it in a smart way that meets both the war-fighters' needs and those of our crews," said Maj. Kathryn Nelson, who is helping to plot the future of the UAVs at Air Combat Command in Virginia.

Nelson, a former B-1 bomber pilot, has flown Predators and Reapers over Afghanistan for the better part of five years. So, too, has Maj. Matt Martin, a Predator pilot who oversees UAV training and operations at Air Combat Command. He offers some different arithmetic from that of Herz.

"The [Herz] study didn't capture all of the most recent and relevant data," Martin said. "Right now, our attrition rate - which is different from our mishap rate - is 5.3 attritions per 100,000 hours."

Martin also said the earlier data do not take into account the increased demands on the UAVs, which had them flying more than 100,000 hours last year.

All Predator crashes are "mishaps," but not all mishaps result in "attrition," or the loss of one of the $4 million aircraft.

"About half of those attritions are the result of some kind of mechanical failure, and half is a mixture of human factors and combat losses, or decisions to take a higher risk," Martin said. Of the human-error losses per 100,000 hours, "about two of those are a result of crew error, and one is a landing mishap."

Because of the delay in signal transmission over 7,000-plus miles from the U.S. bases, forward-deployed pilots handle the takeoffs and landings through a C-band line-of-sight data link.

It's not the same thing as being in the cockpit.

"It's a very challenging airplane to land," said Martin, a former RC-135 pilot who has commanded a forward-deployed takeoff-and-landing unit in Iraq and continues to fly one weekend a month at Creech Air Force Base, Nev., to stay current in the Predator.

Much of that difficulty in taking off and landing is visceral.

Martin cited "the combination of not being aboard the airplanes so you can't hear the engines spool up, you don't feel the ground rush, combined with you having no peripheral vision because you're looking through a nose camera, and you have to do a purely visual interpretation of your instruments."

Predators flew 138,404 combat hours in 2008, up 94 percent from a year earlier. Reapers flew 12,770 combat hours, and those figures are expected to double this year.

Those figures are driven by Gates' demand for the Air Force to establish 50 combat air patrols (CAPs), the term for 24-hour-a-day coverage zones, by 2011. The service is providing 35 CAPs now, 31 with Predators and four with Reapers, and the increase from 35 to 50 is expected to be all Reapers. The last Predator is scheduled to be delivered in 2011.

An automated takeoff-and-landing system is due for the Reaper in 2012. In the meantime, tests on the laser altimeter were completed in early July, and modification kits were due out in August to offer pilots a better sense of the runway.

A pitch-indication system is being tested and is not yet mature enough for use. But it likely will be speeded up so pilots will know that the nose of the plane is up during landing. The Air Force says that touching down nose-wheel first is the primary cause of human-faulted crashes during landing.

But even the auto-takeoff-and-landing system won't completely remedy the issue, because it will be limited by crosswinds. Anything above 10 knots will be handled by a pilot.

And what of the Predator? The demands of an auto system are too heavy for the lightweight craft, the Air Force says.

"The Reaper is a bigger, faster aircraft, 10,000 pounds [compared with] 2,300 pounds," Nelson said. "We don't think combatant commanders would want to take off fuel [from the Predator], which takes off persistence, or any of the other payloads that we could bring, be it weapons or sensors."

Instead, the laser altimeter tested on the Reaper is being considered for the Predator. It would offer input that would keep the pilot from putting the airplane into a negative pitch.

"That's autopilot logic software that's available by adding only the laser altimeter as a physical modification," Nelson said. "It would allow the pilot not to get himself into trouble, providing an 'assistant.' The pilot would still be doing the landing, but he would be landing a smarter airplane."

The question remains: Why has this taken so long? "The Air Force just told us they weren't interested" in buying an auto-takeoff-and-landing system, said Tom Cassidy, president of General Atomics Aircraft Systems Group. He said the system was not too heavy for the Predator.

Regardless, the Air Force admits it's still trying to catch up to technology that's 15 years old, but which has largely been adapted in a hurry-up fashion. In a radical departure from most Air Force planes, which are developed and tested over decades, the Predator was in the service's arsenal soon after the contract with General Atomics Aeronautical Systems was signed.

That contract followed a General Atomics sales pitch that foresaw the demand for the intelligence, surveillance and reconnaissance offered by the UAV, with the potential for weaponry. Since the UAVs were introduced into combat, ground commanders continually have demanded more intelligence coverage. ■