Jonathan Newell looks at a combination of cameras and HUD to provide helicopter pilots with a clear vision of difficult approaches in severe weather conditions.
Developed by Israeli commercial and military aviation technology specialist, Elbit Systems, the “Clearvision” Enhanced Flight Vision System (EFVS) range of products is designed to give fixed-wing and helicopter pilots greater awareness of their surroundings, including obstacles, when making challenging landing approaches.
Covering the full flight envelope, the recently-tested helicopter version of Clearvision is designed to give broader access to those destinations that suffer from intrinsic low visibility or the kind of weather conditions that limit the accessibility of aircraft both during the day and at night.
The enhanced ability to fly missions in such difficult conditions will benefit search and rescue missions and offshore oil and gas field transport duties.
Field of view fusion
The Helicopter Clearvision system comprises two distinct technology elements which have been blended together to give the pilot a combined image of the real world outside the cockpit window and the enhanced reality supplied from vision systems.
Packaged in a single Line Replaceable Unit, the HeliEVS vision system uses multi-spectral sensors to capture and display terrain in darkness and reduced visibility. The output from the sensors is fused with global terrain database information to generate a combined image using a Combined Vision System (CVS). The CVS provides a high-fidelity view of the outside world even when actual visibility is zero. It therefore provides the pilot with effective situational awareness even in total darkness, fog or dense haze.
By fusing both synthetic and real-time imagery using a unique design symbology and computer flight guidance, this technology provides helicopter pilots with a “real-world” view of the terrain along with all the obstacles within their flight path, allowing them to “see and avoid” them even when visibility outside the aircraft is limited.
Pilots receive the CVS output on a “Skylens” Head-Up Display (HUD) using high-resolution symbology and video on a transparent visor. With such technology, they are able to operate with “eyes out” of the cockpit rather than engrossed in instrument readings within the aircraft.
Final flight testing
In final flight tests, HeliEVS and Skylens were able to successfully demonstrate a fully operational configuration combining the EVS sensor, HUD and fused image display processor.
Performed on board a BO105 testbed helicopter, the tests involved using the system during different hours of the day and in various locations. This included a variety of manoeuvres such as rooftop landings and oil rig approaches above the sea, in order to evaluate real operational flight conditions during search and rescue, emergency medical services and rig transportation missions.
Flights results indicate significant contribution to situational awareness and safety, with pilots indicating that they could recognise obstacles and landing points around the oil rig from far away, even at night and from long distances. As such, they were able to plan optimal approaches ahead of time.
Increased mission success
With the successful conclusion of final flight tests, the combined HeliEVS and Skylens system will soon find its way into the cockpits of those helicopters flying the most difficult and dangerous missions.
Enabling the pilot to fly in a head-up orientation for the duration of the mission improves flight safety and situational awareness, increases mission success rates and minimises the dependency on airport and helipad instruments.