Military, Products, Services

Manned or Unmanned? How About Both?  

By By Ernie Stephens, Editor-at-Large | September 1, 2012

The U.S. Marine Corps has employed the unmanned K-Max in the cargo resupply role in Afghanistan since November 2011.

Thanks to the digital age, remotely piloted aircraft barely rate the raising an eyebrow, unless you’re on the battlefield and one is about to save the day for you. They have names like Predator, Fire Scout and Global Hawk. And who knows how many are still “black projects” that only a select few people in the military are aware of? But one unmanned aerial vehicle (UAV) that I’ve been casually following or several years now has been hard at work in-theater on the other side of the world since November 2011. It is the K-Max unmanned aerial truck (UAT).

I need to stop and clear something up already. The K-Max UAT—a joint venture of Bloomfield, Conn.-based Kaman Aerospace, and Bethesda, Md.-based Lockheed Martin—isn’t always unmanned. Technically, it’s an “optionally manned aircraft.”


Unlike most other military aircraft that can either fly exclusively with a pilot onboard handling the controls, or exclusively without one, the UAT is the first operational, publicly acknowledged rotorcraft that can switch back and forth from manned to unmanned an unlimited number of times, and do so in a shocking 15 seconds or less.

I went up to Connecticut to get more information from the people at Kaman, who designed and built the single-seat, single-engine K-Max. There I met Terry Fogarty, general manager of the Unmanned Aerial Systems group, and Mike Bielefield, program manager for the K-Max UAT. Both have been with the company for decades.

Founded by aerospace engineer and inventor Charles Kaman (1919-2011), Kaman Aerospace and its 2,300 employees design and turn out components for nearly every make and model of aircraft flying today, listing Airbus, Bell, Boeing and Sikorsky as major customers. Besides the K-Max, Kaman builds and supports the SH-2G Super Seasprite, a highly capable, twin-engine maritime helicopter in service with several foreign navies.

“The K-Max was certified in 1994,” noted Fogarty of the aircraft that quickly became the helicopter of choice for forestry, construction, and other long-line applications. “Since then they’ve flown 280,000 flight hours.”

With a basic empty weight of 5,500 lbs. and low direct operating costs, the K-Max impressed its operators with its ability to carry a 6,000-lb. load under its belly, and take 4,000 lbs. to altitudes of 12,000 feet. Its strength is a product of it intermeshing rotor system, which counteracts torque without wasting power on lateral thrust, the way a conventional tail rotor-equipped helicopter does. Those strengths made the K-Max a likely candidate to fill the U.S. Marine Corps need for a battlefield resupply transporter in the Middle East. And with so many of its personnel being killed and wounded along convoy routes in Afghanistan, a relatively small and low-cost helicopter with great lifting capabilities could not arrive soon enough.

But why not take the capabilities of the K-Max and ramp it up one more notch by taking the pilot out of harm’s way, too? 

Optionally manned Kaman/Lockheed Martin K-Max in Afghanistan.

Decades before his death, Charles Kaman had envisioned a full-size, remotely operated helicopter, and shared that idea with his engineers, some of whom are still with the company. That idea was revived in 2007 when work began on the K-Max UAT.

Unfortunately, a late-1990s drop in new orders had caused Kaman to temporarily close down the K-Max assembly line, making it impractical to build just a handful of the model for battlefield development. Luck, however, was on the engineers’ side.

Congress had given five K-Maxs to Colombia. But after years of underutilization there, the aircraft went up for sale on the open market. Kaman bought three of them back, and went to work with Lockheed on repurposing them as unmanned platforms.

“The folks at Lockheed are great to work with,” said Fogarty. “We have learned some things from them, and they have learned some things from us.”

According to Fogarty, as development continued, the engineers found a need to keep the pilot onboard to help monitor the aircraft’s performance, and to satisfy the FAA, which was still skeptical about any unmanned aircraft flying in U.S. airspace. With having to keep a person in the cockpit, even when the vehicle was being remotely piloted, engineers realized that they had, in effect, designed an optionally piloted aircraft.

That partnership resulted in the K-Max UAT prototype, which led to a $45.8-million contract awarded by the U.S. Naval Air Systems Command in 2010 for an unmanned, forward deployable, resupply aircraft.

“The [K-Max UAT] was specifically designed for the battlefield cargo resupply mission,” said Dan Spoor, Lockheed Martin Aviation Systems vice president by way of a joint press release. Its capabilities “directly answer the Marine Corps’ requirement to augment ground and air logistics operations, supplement rotary-wing assets, and keep warfighters supplied and out of harm’s way.” 

U.S. Marine Corps controls for the unmanned Kaman/Lockheed Martin K-Max UAT.

The contract included delivering a pair of K-Max UATs to the Marines for their assessment by the summer of 2011, which the team did on time and on budget. And after several successful test phases, both were deployed to Afghanistan.

After two deployment extensions, 485 sorties, 525 flight hours and 1.6 million lbs. of cargo delivered, Vice Adm. David Achitzel, commander of U.S. Naval Systems, declared that the K-Max “...eliminates the need for manned ground convoys, reducing the number of our warfighters exposed to improvised explosive devices.”

The mechanics of being able to fly a full-size aircraft remotely, yet make it easy to switch back into a conventionally piloted vehicle, was something I wanted to see firsthand. So, Fogarty took me to the other side of the complex for an on-site look at the UAT.

Contrary to the way it looks in the air, the K-Max is a relatively big helicopter, considering its single-seat design. It measures 13 feet, 7 inches tall, and about 52 feet from the forward-most blade tip to the tail fin.

Fogarty and Bielefield were happy to let me poke around most of the aircraft, but for security reasons they would not let me photograph it. I can tell you, though, that if you didn’t already know the aircraft could be remotely piloted, nothing in it would have immediately tipped you off. The actuators that move the flight controls while in remote mode are mounted out of sight, and are engaged by a single, unremarkable-looking switch inside of the cockpit.

Speaking of that switch, which I was asked to not describe, it is the reason the aircraft can be converted from manned to unmanned so quickly. Basically, a pilot climbs aboard the K-Max, completes a number of preflight checks, then lights off the 1,800-shp Honeywell T53-17A-1 gas turbine engine. If he will be remaining on board to fly it, he will place the switch in the manned position. If it will be remotely piloted, he will put the switch in the unmanned position, climb out, and walk away. Consequently, the amount of time it takes to convert the K-Max UAT from manned to unmanned is based entirely upon how long it takes someone to manipulate one switch and get out of the aircraft.

Of course, the other part of any unmanned system is the communications link. Lockheed Martin handled much of those issues, but input on how to design the remote station was a joint effort between all involved, including the end users.

“The Marines said way back in the beginning, ‘We want something the guys will be comfortable with,’” reported Bielefield. “So, we bought PS2 controllers, and reprogrammed them!”

But the design teams went one step further in their quest to make the system user-friendly for the young, front-line Marine. Instead of programming the controls to mimic a collective, cyclic and anti-torque pedals, they set the controls to follow an overall instruction. For example, let’s say you wanted to climb a few hundred feet. To make the aircraft go up, push the “up” control. The helicopter will understand what you want to do, and make the proper power, collective and cyclic inputs needed to make that happen. In fact, takeoffs, landings and hovers are handled by the press of a button.

With no real-world rotorcraft flying skills needed to master the UAT, Bielefield boasts that anyone—regardless of aviation background—can be taught to fly the K-Max remotely. He has personally seen support personnel become quite proficient with the controls in just two weeks.

The other part of the control rests with the computers and base stations. Once mission commanders have decided what routes the UAT should fly, Bielefield says it takes about 20-30 minutes to program those instructions into the computer. Once done, the controller at the primary base will press the takeoff button, engage the flight director, and monitor the aircraft’s progress using a map overlay on a laptop computer. Upon its arrival at each destination, another Marine with a smaller, more local line-of-site control station will fly the UAT to the exact touchdown point, even if it means selecting a different landing spot.

Dealing with multiple deliveries was engineered into the system, too. A four-hook carousel can replace the single-hook configuration on the K-Max. The flight can then be programmed for the release of the ammunition attached to hook #1 at Alpha Base, the rations on hooks #2 and #3 at Bravo Base, and the medical supplies slung to hook #3 at a field hospital.

And because things in a combat zone can change rapidly, the UAT can be told to halt and hover while new instructions are laid in.

Another thing engineers wanted to design in was a way to deal with a loss of communication between the ground and the aircraft. The software experts took care of that by allowing the UAT to be programmed with radio failure instructions. If it loses its signal, it might be under orders to continue with some or all of its mission, or know that it should immediately land itself back at its home base.

There was one last item the people on the Kaman-Lockheed Martin team had to plan for: an engine failure. Sophisticated sensors were placed aboard the aircraft to detect catastrophic engine failures. Should one occur, the aircraft will automatically enter an autorotation and put itself on the ground. It won’t have the ability to pick and chose a flat surface over an inclined one, though. It will simply land wherever it ends up.

In all fairness to other manufacturers—including those with UAVs on the drawing board, undergoing flight testing, or buried under a cloak of government secrecy—their systems may be equally as capable as the one designed by the people at Kaman Aerospace and Lockheed Martin. But for now, the K-Max UAT, with its innovations and in-theater performance, has amassed a decent reputation with the Marines, and is doing for them what no other platform has done thus far.

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