The Thales TopMax wearable head-up display (HUD) will see its first business jet application with certification planned for the Bombardier Challenger 350. StandardAero will engineer the supplemental type certificate (STC) for the Challenger 350, which is expected to be approved by the end of 2020, followed by the Challenger 300 and 605/650 and then other airframes.
The TopMax HUD is a lightweight head-mounted device that can fit over either eye, depending on which one is dominant, and unlike other HUDs it can display full-color imagery. Because it is wearable, the pilot can view synthetic vision system (SVS), terrain, obstacles, and other imagery with a 360-degree and essentially unlimited field-of-regard. With a traditional fixed HUD, the pilot must be positioned precisely in the eyebox to look through the combiner glass, and HUD imagery is only viewable within the fixed field-of-view in front of the HUD.
Pilots flying with TopMax can view imagery by looking in any direction, as well as up and down. This can be helpful when needing to view a SVS runway centerline that isn’t in front of the aircraft but is, for example, well to the right or left of an airplane on a downwind leg to the runway. In this case, the pilot can turn his or her head to the side to see the SVS runway centerline in the TopMax display to maintain situational awareness. TopMax can also display enhanced vision system (EVS) imagery and thus be used to facilitate lower takeoff and landing minimums. Ultimately TopMax will be able to deliver a combined vision system, with EVS and SVS imagery combined.
A key benefit of the TopMax HUD is that it is much simpler to install, because the wearable portion is not permanently installed, and TopMax connects to existing avionics. The system includes a control panel and interface display processor, plus special stickers that are installed on the flight deck ceiling to map the HUD and the position of the pilot’s head. An infrared sensor on the TopMax headgear, which contains inertial sensors, detects the stickers and thus orientation of the pilot’s head. Because its footprint is so small, TopMax can fit into very light jets and single-engine turboprops, as well as large jets. Total system weight is about eight pounds and price will be about half that of traditional HUDs. Installation time should be three to five days.
“You don’t have to adjust your body to the system like a conventional HUD,” said Thales test pilot Frederic Scarfone. “With a traditional HUD, you move your eyes, but with the TopMax you move your head.”
I tested the TopMax HUD at the Thales exhibit (Booth C13239) on a simulated approach to Chambéry-Savoie Airport in France, an ideal location for night approaches at an airport surrounded by mountains. Once set up on my dominant right eye, the headgear felt completely unobtrusive and I wasn’t aware of its well-balanced 1.1 pound weight. The SVS imagery of the mountains surrounding Chambery was depicted in a yellow-orange color that made them stand out prominently.
I could see the EVS imagery when looking straight ahead along the axis of the airplane because the EVS sensor only looks forward. When I turned my head, I could see the SVS-depicted mountains in any direction, as well as ADS-B In traffic.
Moving my head up slightly, I could see the flight mode annunciator scorecard indicating the state of flight director and autopilot modes. If I moved my head down, the partial HSI on the bottom bloomed into a full 360-deg HSI.
The TopMax also has all the regular HUD symbology such as flight path marker, flight director cue, energy caret, airspeed, altitude, radar altitude, glideslope, localizer, and so on. The airspeed and altitude are depicted in white, while the other symbology is green.
After a few minutes of wearing the TopMax, I felt like it wouldn’t take long to get used to flying with it. For pilots who eschew using a HUD because they don’t have extensive backgrounds flying with it, TopMax is comfortable enough to make flying with it full-time much more likely, bringing the safety benefits of HUD to more pilots and aircraft.
More than 200 pilots have tested TopMax in a simulator or in Thales’s Cessna 406 turboprop twin. “There is always always a little pushback in the sense of putting something on their head, which they’re not used to,” said Yanik Doyon, TopMax director of sales and marketing. “But they realize it’s not intrusive and is comfortable. Once they try it, they really understand the value beyond what a traditional HUD can bring.”