Losing control in a cloud of dust kicked up on landing is a troublingly common plight for military helicopter pilots. Sierra Nevada Corp. is testing a technological solution that will also be offered for civilian use by medevac and other special-mission operators who can’t afford to wait for dust or snow to settle.
Dean Heitkamp, the company’s senior director of business development who has firsthand experience flying military helicopters in Korea, Afghanistan, and elsewhere, said “whiteouts” and “brownouts” are particularly perilous when a large number of helicopters converge on the same patch of desert, and the dust cloud created by the first only grows as followers arrive. Military pilot training has improved over the years to try to cope with this common problem, but landing in zero visibility conditions remains very dangerous, even if nobody is shooting at you.
Heitkamp said flight testing and experience have led engineers to the conclusion that there is not one single solution that will cut through clouds made of snow, sand, and smoke, so Sierra Nevada’s Degraded Visual Environment System project team opted to combine a few: infrared cameras that operate in various wavelengths, millimeter wave radar, and lidar. Each has strengths and weaknesses, and determining the right mix of sensors depends largely on the operating environment and the mission.
Sierra Nevada developed its own millimeter wave radar system, selecting a wavelength that is optimized for helicopter requirements. The company then incorporated infrared and lidar sensors made by others, and fused them into a single system that combines sensor images with terrain maps and aviation symbology into a single image that can be displayed in the instrument panel, or on a head-up display. The company is currently testing the system with a helmet-mounted display as well.
DVES is a step beyond synthetic vision and enhanced vision supported by cameras or other sensors.
“We have done all of that, but we’ve also combined it with that computer model,” Heitkamp said, noting that the combined display also incorporates “synthetic vision” based on GPS-referenced terrain maps. “Ours is a little bit of everything.”
While the system is not yet deployed at scale in the U.S. Army and Air Force fleets, the potentially lifesaving value is so high that the company opted to invite civilian customers to inquire. The cost of the system will vary widely, depending on mission requirements, how much equipment the aircraft can carry (a limitation not so much about weight as the available space for electronic boxes), and a range of other factors. Expect the low end to be around $100,000, ranging upward to $1 million or more.
For firefighters, medevac operators, offshore oil platform shuttles, and others who must fly to the limits of visibility in all kinds of weather and terrain, the value of being able to see clearly from inside a thick cloud of dust, smoke, or snow is obvious enough that Heitkamp believes DVES will find a market outside of the military contracts to come.
“I think that first group is those folks…who find themselves having to fly in less than optimal conditions, and may or may not have a choice,” Heitkamp said. The system and sensor package can also be adapted for fixed-wing use by cargo haulers and others who have a strong motivation to deliver on time.
“This is going to do for [degraded visual environments] and weather kind of what night vision goggles did for nighttime,” Heitkamp said. “We’re really excited about it. Our goal is not only to reduce or prevent accidents, but also enable greater operations in lower visibility.”
Heitkamp said another potential market has yet to emerge: Urban Air Mobility. On-demand taxi service connecting city rooftops will require something like DVES to achieve the operational safety and flexibility that UAM will demand, he noted. Any aircraft that delivers rapid, reliable service in this much-anticipated market is “going to have to have this kind of technology.”