William Steele was working on developing a low-cost HUD (Heads Up Display) product when a eureka moment transpired.
“I started down the path of using an HUD with the plate of glass you have to look through, and then, one day, I was playing with a laser pointer at my dad’s house, and I pointed it up at the ceiling fan, and as soon as I hit the ceiling fan with the laser point, I went, ‘Oh, that’s it!’”
What Steele observed that day two and a half years ago was that anywhere within the fan’s arc that he pointed the laser, the beam appeared is if projected on a solid surface. That meant a propeller at the front of an airplane could serve as a virtual surface on which the HUD image could be projected, eliminating the need for a combiner—the high-tech glass plate that HUD systems in business jets require—and opening the door to the creation of a low-cost HUD unit.
Steele recounted the story at the VirtualHUD booth outside of Hangar A at Sun ’n Fun, where the Lawrenceburg, Ind.–based company was displaying its portable NightVU HUD and a prototype of its installed ForwardVU HUD unit.
The HUD system allows flight data to be projected into the pilot’s “through-the-windshield” view, reducing the need to look down at the instrument panel at critical phases of flight.
The unit mounts to the inside of the windshield.
VirtualHUD’s units project airspeed, heading and altitude, and also are capable of projecting full-color synthetic-vision data from installed or portable digital navigation systems, as well as enhanced-vision (EV) images from infrared cameras. Thus, they provide the same capabilities found in business jets with top-of-the-line HUD units costing hundreds of thousands of dollars, at a four-figure price.
The portable NightVU is for night use only, as the projected image isn’t bright enough to be seen in daylight. (For both units, the company recommends taping or painting a half-inch-wide white stripe on the backside of the propeller to improve image clarity.) The portable unit has a built-in GPS; attitude, heading and reference system (AHARS) sensors; and a digital compass. Relatively compact at 6x4x1.5 inches, it weighs about 1.5 pounds and mounts to the inside of the windshield via a supplied RAM Mount ball socket with suction cup. Power is provided through a panel’s standard 12-volt power source. The laser is projected through a lens on the front of the portable unit, and a focusing ring allows the image to be adjusted for best viewing. The laser beam doesn’t extend beyond its focusing point, negating concerns about the hazards of errant laser beams. A menu select button accesses an internal menu, and there’s also an RS-170 NTSC video signal—which allows input from sources including EFIS displays, compatible handheld devices and infrared EV camera—that can be projected along with the air data though the HUD unit.
The ForwardVU is an installed system that relies on an aircraft’s digital GPS and navigation system as its data source. The unit measures 10x9x3 inches, weighs about four pounds and can be oriented in any geometric plane behind the panel, making it easy to accommodate in virtually any GA aircraft.
“I’m building an RV8, and I have it all the way up against the firewall, and there’s absolutely nothing there [to hamper installation],” Steele said.
A periscope-type mirror projects the image created by the unit up through the top of the panel and onto the back of the propeller. The efficient and powerful 7,000-lumen light draws six amps on startup and two amps in normal operation.
The unit's laser projects data on the backside of the propeller.
The company’s booth wasn’t the ideal environment for demonstrating the systems (it’s impractical and unsafe to have a propeller spinning in such a display area). Instead, the portable unit was set up to project the HUD image onto a spinning propeller from a radio-controlled aircraft engine, while the hard-wired installation was projected onto the blades of a large fan. Both units have 1,024x768-pixel, high-resolution capability, though the display units were hooked up to low-resolution sources.
The portable unit was connected to a video taken in flight through an EVS-100 infrared camera at night. The horizon was marked by a green line, and the air data, horizon line and image of hilly terrain below were all visible on the back of the tiny propeller. Steele tilted the unit from side to side to simulate a banking aircraft, and the ersatz change in attitude was easily visible. The installed version used output from an MGL Avionics Odyssey MFD screen and a live infrared camera as its image source.
The units also can project highway-in-the-sky (HITS) symbology, the rectangular “boxes” that depict an aircraft’s ideal flight path for a selected route, approach or departure. Steele notes that it’s important to keep the through-the-windshield view from becoming too cluttered with data, and says VirtualHUD will work with OEMs of digital NAV gear to develop optimized output data for use with the VirtualHUD products.
“We’ve had a lot of interest from manufacturers, especially light-sport aircraft [manufacturers],” Steele said. “We’re working with at least five different vendors, but none we’re ready to talk about. And we’ve dealt with every single GPS [manufacturer] out there; the units can work with any of them.”
Steele expects a noncertified version of the ForwardVU to be available sometime this summer. Both the portable and installed units are priced at $7,495. The installed version also can be outfitted with GPS and AHARS capability for use in aircraft that don’t have digital navigation systems to feed data to the unit (for an additional $1,500). Steele estimates the ForwardVU’s installation time will require two to five hours for a retrofit, and less if it’s put into the panel during construction. For more information, visit www.virtualhud.com.