Pilot Report: Embraer’s New Eyes
HUD Has Both Enhanced and Synthetic Vision
This article appears in the January 2017 issue of Business & Commercial Aviation with the title “Embraer’s New Eyes.”
We recently visited Embraer’s impressive and much expanded campus in Melbourne, Florida. While there, we strapped into the left seat of Legacy 500 Serial Number 52 for a demonstration of its Rockwell Collins HGS-3500 compact head-up display, EVS-3000 multi-spectral enhanced vision system and synthetic vision capability.
This is Embraer’s first aircraft to have the certified version of E2VS, short for Embraer Enhanced Vision System. It was FAA-approved in September 2016 as an enhanced flight vision system in accordance with Advisory Circular 90-106A. Accordingly, it can be used for credit to fly down as low as 100 ft. above the touchdown zone elevation before the flight crew must see the runway environment with unaided vision in accordance with FAR Part 91.175. However, when the HGS-3500 is displaying synthetic vision background imagery, the system cannot be used to fly down to lower than published approach procedure minimums.
Accompanied by Sydney V. de M. Rodrigues, senior demonstration, instructor and Legacy 450/500 standards pilot, in the right seat and Peter Kruger, senior demonstration and safety pilot, on the jump seat, we taxied out from Embraer’s ramp at Melbourne International Airport (MLB). Even though the weather was too clear to show off all of the system’s capabilities during low visibility approaches, its value became apparent as soon as we started rolling down Taxiways G and K toward the approach end of Runway 9L. We could see the thermal image of Embraer’s taxi director on the ramp, the pavement edges, along with the taxiway and runway paint stripes. The thermal image is slightly offset to the left from the actual pavement and paint stripes due to parallax between the left-side-mounted HUD and center-mounted EVS-3000 camera array.
The long-wave infrared (IR) sensor of the EVS camera array enabled us to see down the taxiway two or three times farther than we could using our own eyes and the aircraft taxi lights. The shortwave IR and electro-optical visible light sensor enabled us to see both incandescent and LED/sodium vapor/mercury vapor light sources. We also could see the infrared exhaust signatures or proximate turbine aircraft, but not the four-cylinder Piper Cherokee in the left traffic pattern.
Rodrigues used the FMS to compute takeoff V speeds and takeoff field length. We noted that s.n. 52 is 329 lb. heavier than what Embraer quoted for BCA’s May 2016 Purchase Planning Handbook. With 5,990 lb. of fuel and one passenger, our computed takeoff weight was 30,260 lb. At Melbourne’s 33-ft. field elevation, at 25C and using Flaps 1 for takeoff, V1 and Vr were 112 KIAS, V2 was 120 KIAS and en route climb speed was 140 KIAS. Takeoff field length was 3,379 ft. with 6,000 ft. of pavement available.
Cleared for takeoff, we advanced the thrust levers until the autothrottles engaged. The lightly loaded aircraft had a 1:2.15 thrust-to-weight ratio, so acceleration was brisk. When Rodrigues called “Rotate,” we immediately were reminded why the Legacy 500 is such a pleasure to fly. Pitch response to the sidestick input was crisp but well damped. It was easy to follow the flight director cue in the HUD.
We settled into a comfortable 180 KIAS climb. Tower asked us to maintain the 094-deg. runway heading until 1,500 ft. for noise abatement. After switching over to Orlando Departure, we were cleared to climb southeasterly through broken cumulus to 5,000 ft. MSL. We could see the shapes, sizes and tops of the clouds both in the HUD and on the head-down displays with the help of the EVS IR sensors. Rodrigues showed us how to use the background imagery on/off button on the left sidestick to check visibility with unaided vision. That check is essential when flying approaches down to minimums.
OK, we admit it. We’re HUD junkies. It’s so much easier to fly an aircraft with smoothness and precision when using the HUD’s flight-path vector and 1:1 conformal symbology than it is with a compressed imagery head-down display, in our opinion. And it keeps the pilot head-up and with eyes looking outside the cockpit. It could be the biggest safety breakthrough since the invention of the windshield.
For the first approach back at Melbourne, though, Rodrigues elected to switch to synthetic vision for the background imagery so that we could see how it works in comparison with enhanced vision.
SVS, as it uses the aircraft’s own TAWS terrain database, will provide situational awareness even if the clouds are so dense that they obscure the view of the enhanced vision camera array. SVS provides dome images over nearby airports, high-resolution terrain contours, lead-in lines to runway centerlines and runway outline imagery. In addition, in clear weather it can help the pilot visually acquire airports and runways in urban areas, which often can disappear in a sea of lights from buildings, roads and housing developments.
But switching between SVS and EVS for background HUD imagery requires use of the cursor control device and a series of drop-down menus. We’d prefer a vertically mounted, two-way, momentary contact rocker switch in place of the background imagery on/off button on the sidestick. One side of the rocker could be used to turn on/off the EVS and the other could be used to turn on/off the SVS.
As we approached Runway 9R using the RNAV (GPS) LPV procedure, SVS showed us the extended runway centerline. The closer we got to MLB, the runway outline image became ever larger. At the published 232 ft. MSL (200 ft. AGL) decision altitude, we executed a go-around and set up for the ILS Runway 9R.
This time, we switched from SVS to EVS imagery. As we peered through the HUD, it was quite apparent that improvements have been made by Rockwell Collins and Embraer to the multi-spectral EVS camera since we first flew the system in Brazil. The gains between the two IR sensors and low-light camera have been harmonized to provide a more realistic image of lights, terrain and pavement. We could see Interstate 95 and Ellis Road, for instance, east of the airport. We also could see the thermal signatures of the high-intensity runway edge lights on Runways 9L and 9R, plus the MALSR array leading us to Runway 9R.
Rodrigues also could see everything detected by the EVS camera in an upper left window of the right-side display screen. He also had SVS imagery displayed on the right-half PFD so that he could compare the two.
Rodrigues called “minimums’ at the ILS 232-ft. decision height and we replied “Continuing.” We flew down to 132 ft. MSL, switched off the EVS to take a brief look at the runway and executed a second go-around.
For our final approach, we again flew the ILS Runway 9R using EVS. This time, we switched off the EVS at 132 ft. MSL (100 ft. AGL) and continued for landing using the HUD with unaided vision.
We again switched on the EVS for the taxi back to Embraer’s Melbourne campus, providing a much-enhanced view of the pavement, paint stripes, lights and drainage ditches along the sides of the taxiways.
Conclusions? The combination of the HGS-3500 and EVS-3000 provides tangible cost benefits in the form of being able to fly down to lower-than-published minimums. Its intangibles include flying with VFR precision and smoothness in IMC and much improved situational awareness.
Embraer is pricing the HGS-3500 at $275,000 and the EVS-3000 at $275,000, if they are purchased separately. Together, the package will be available for just over $500,000. That’s roughly half the cost of conventional stand-alone HUD/EVS packages. Apparently, many Legacy 500 buyers see the value of the system. Before it was certified, more than half of the customers were ordering their aircraft with provisions for both systems. Now with the system’s FAA and EASA approvals, 80% of operators with HGS/EVS provisions are installing it.
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