News | Jan 18, 2018

Navy engineers have an ingenious device for locating downed pilots

Product development using Navy invention begins with patent license agreement

News Article Image of Navy engineers have an ingenious device for locating downed pilots

Students from the USAF Pararescue School load patients for aeromedical evacuation during a mass casualty exercise in New Mexico on January 6, 2018. (Jim Fisher/Air Force)

On March 21, 2011, at about 11:30 p.m. local time, a U.S. Air Force F-15E Strike Eagle crashed in northeast Libya.

The American pilot and weapons officer, flying a United Nations-sanctioned mission against regime forces controlled by Libya’s then-President Muammar Gaddafi, safely ejected before the crash.

Maj. Kenneth Harney is welcomed home at RAF Lakenheath

Maj. Kenneth Harney is welcomed home at RAF Lakenheath, England, on March 26, 2011. The Air Force concluded that his fighter jet crashed over Libya after it became extremely imbalanced. (Air Force photo)

The two airmen separated after they exited the aircraft. The weapons officer was greeted by friendly Libyans and returned safely with their help, but Maj. Kenneth Harney, the jet’s pilot, needed an immediate pickup with hostile forces in the area.

From the deck of the nearby USS Kearsarge, Marine forces had Harney secured in 90 minutes

Improving Personnel Recovery

To aid downed aircrews, sailors, and others in need of rescue, Navy researchers have developed a unique device to locate and identify isolated personnel that do not have access to a radio.

It’s called a Polygonal Asymmetric Reflector and was invented by Gerry Miller and James Stewart at the Naval Surface Warfare Center in Crane, Indiana.

And on Aug. 29, 2017, the Navy’s patent application was approved and the technology is ready for a commercial license by businesses that would develop it into an available product.

How does the PAR work?

The device is made of special panels that snap together to form a geodesic shape and are embedded with fractal antennas that reflect back the radio signals emitted by a plane or unmanned drone passing overhead – no batteries needed.

And based on the design of the panels, a unique signature signal is received back by the aircraft that can then be compared against a library of stored signals.

PAR patent drawing

This novel communication allows search and rescue personnel to identify who and where a person is. And by applying shield covers to the PAR panels, the stranded personnel can also transmit information on their status, e.g., desire for immediate extraction, medical assistance, the presence of enemy forces, or if no assistance is needed.

Plus, the passive nature of the PAR means it won’t highlight the location of isolated personnel to unfriendly forces.

And the researchers say the source of the radio signal doesn’t necessarily have to be new to the aircraft.

It “can be designed to reflect/resonate an altered RF signal based on specific aircraft RF emitters such as a search radar, a weather radar, a fire control radar, etc.,” according to the patent.

The Business Opportunity

The Navy invention is now available for use by businesses to develop new or improved products. The first step in development is licensing the intellectual property from the Navy.

“This is an interesting technique for locating personnel on the ground with some obvious advantages,” said Sean Patten, TechLink’s senior technology manager who is marketing the PAR. “And besides the Navy, we know the Air Force is also seeking improvements to future recovery missions, and they’ve been asking about technologies that can locate and authenticate isolated personnel without putting additional forces at risk.”

TechLink, the Department of Defense’s national partnership intermediary, specializes in working with businesses and government laboratories on patent license agreements. Many of the military’s inventions have dual uses that could develop both government and civilian product markets.

“We’ve got a great relationship with the Navy lab at Crane and they’re easy to work with,” Patten said. “If you’re interested in the technology, give us a call. We’ll walk you through the steps from start to finish.”

Troy Carter can be reached at or 406-994-7798.

Headshot Image of Sean Patten, CLP

Is your business interested in one of these hot technologies?

Contact Us