Avionics reducing the risk of disaster

Helicopter accidents caused by reduced visibility due to sand and dust are a big problem. So-called “brownouts” can occur during helicopter landing and take-off operations in arid desert terrains.
Ground obstacle collisions or rollover due to landing on uneven slopes can be caused by the intense, disorienting dust clouds stirred up by the helicopter rotor downwash.
A NASA report blamed brownout for being behind more military helicopter accidents than any other cause, calling it a $100 million per year problem for the US military in Afghanistan and Iraq.
So it is no surprise that avionics companies have been trying to solve the problem.
While simple radar is one potential solution, synthetic vision systems (SVS) are proving to be another tool. SVS is able to provide a computer-generated depiction of the area around a helicopter, helping to improve a pilot’s situational awareness.
For example, Garmin’s helicopter synthetic vision technology (HSVT) is available as an optional upgrade to the G500H. Using sophisticated computer modelling to recreate a virtual topographic landscape from the system’s terrain alerting database, HSVT gives pilots a clear depiction of ground and water features, airports, obstacles, traffic and more.
When flying in areas where rising terrain may pose a hazard, Garmin's HSVT uses its database to ‘paint’ the landscape with amber or red overlays, showing where potential controlled flight into terrain (CFIT) risks exist. Towers or obstacles are also colour-highlighted with hazard-appropriate symbology.
Honeywell Aerospace completed successful testing of a newly designed synthetic vision avionics backbone (SVAB) for helicopter operators in 2013. It integrated multiple types of sensors with its SVS to provide a 3-D view of the outside world in degraded visual environments (DVE).
Testing was conducted on a Blackhawk helicopter as part of the Defense Advanced Research Projects Agency (DARPA) multifunction radio frequency (MFRF) programme.
In 2015, Rockwell Collins led test activities at the Army’s Yuma Proving Grounds (YPG) to show how its products could help reduce brownout problems.
The company successfully demonstrated its sensor-agnostic synthetic vision avionics backbone (SVAB) solution, which fuses, in real time, multiple DVE sensor types with its high-resolution tactical synthetic vision system (TSVS).
Ryan Olson, senior systems engineer from Rockwell Collins’ Airborne Solutions Engineering, said: “Our testing at the YPG validated a number of advancements in our sensor fusion algorithms that, when combined with our earlier work in radar data fusion, allows us to deliver higher performance solutions to our military customers, while balancing affordability.
“This testing showed that we could efficiently fuse 2D imaging sensors and laser imaging detection and ranging (LIDAR), two prevalent sensing technologies being considered today, into our TSVS.
“This was important because both systems offer advantages and disadvantages in terms of obscurant penetration and enhanced situational awareness information for the pilot.”
Rockwell Collins now offers a flight situational awareness solution called the HeliSure helicopter synthetic vision system (HSVS).
Guillaume Zini, principal business development manager for Rockwell Collins, EuMEA, said: “HeliSure combines integrated visualisation, advanced displays, and industry-leading high resolution database components to provide pilots with a real-world view of terrain and obstacles along their flight path. It is designed to easily integrate active or passive terrain and hazard sensors to provide a comprehensive situational awareness solution for flight in degraded visual environments.”
This minimises the risk of controlled flight into terrain (CFIT) accidents.
“Currently HeliSure is offered on the AW169, AW189, and AW101 from Leonardo’s helicopters division, and will also be available on the AW609 when delivered,” said Zini.
“Initial acceptance by customers was slow, but has accelerated rapidly as they understand the full value of HSVS capabilities. It can be integrated into any of our cockpit display systems, such as the S-92’s Flight2 avionics management system, and may be offered as an add-on to other manufactures’ display systems, should market demand show a need.
“Looking ahead, Rockwell Collins is now developing advanced cockpit avionics systems for retrofit applications that will incorporate our HSVS product, as well as our HeliSure helicopter terrain awareness and warning system (HTAWS).
“Together, these products, coupled with our multi-function display systems, will provide legacy helicopter operators with increased situational awareness and safety, while delivering higher performance and reliability in harsh conditions.”