HEAD UP Displays have been in use by military aircraft for years. They display all the information a pilot needs to carry out his mission. A couple of years ago, Future Systems Technology, QinetiQ, Farnborough and the Flight Research Laboratory of the National Research Council, Canada in Ottawa decided to conduct joint research into whether similar systems could be developed for helicopter pilots.

NRC has one of the very few facilities in the world that is able to virtually replicate every pilot action and QinetiQ has extensive experience in system development of this type. Trials were performed under the aegis of The Technical Co-operation Programme, where information is shared between member countries.

David Thorndycraft, senior military display specialist at QinetiQ, explained: “The overall objective of the trial was to display accurate, low latency world stabilised symbology to pilots to enable safe pilotage in conditions of poor visibility and at night. As we are, in effect, juxtaposing 3D, virtual objects with a real world view, the exact position of the pilot’s head it vital. Full results were published at this year’s European Rotorcraft Forum which has just been held in Marseilles.”

The team has developed a type of night vision goggle that currently tells the pilot only the most basic information, such as how fast, how high and in what direction the craft is flying. Initially, a mechanical tracker was used to track the pilot’s head movements, but this was heavy and cumbersome. Most other trackers are of the magnetic type, so cannot be used in high metal environments.

Virtalis, the world’s leading, independent 3D visualisation company, was able to advise the researchers and supplied the newly developed, non magnetic, LaserBIRD from Ascension. This was evaluated by QinetiQ and NRC as a possible solution to tracking in a high metal, high vibration environment. The optical tracking LaserBIRD was sited just behind the pilot’s head, with the transmitter elsewhere in the Bell helicopter. On its very first flight test, the new system worked immediately, giving six degrees of freedom of movement for the pilot and enabling the system to update the imagery in real time as he moved.

David Thorndycraft added: “During four weeks of flight trials system performance and reliability was excellent considering the very high levels of vibration encountered in the cockpit. Installed yaw axis coverage was limited to about +/- 70-75 degrees owing to the cockpit layout, although this was not considered to be a major problem. Data output was to the Graphics Display Processor (GDP) via RS-232 in continuous 'streaming' mode. In practice, it was found that some filtering had to be added. The combination of the LaserBIRD’s fast update rate of 240Hz together with acceptable latency has enabled QinetiQ and NRC to be able to display accurate world stabilised symbology to the pilot without having to restrict his natural head movements.”

Following the success of these trials, the QinetiQ and NRC team is to spend the next two years working on stabilizing the symbology and expanding the range of information available. There is bound to be significant, international interest in this research from search and rescue organisations and coastguards, as barriers to helicopter flying could be effectively removed. David Thorndycraft, concluded: “This is a world first and the success of the tracking lies at the heart of accuracy of the system. Our system will be easy to build into new helicopters and retrofitting shouldn’t present any difficulty either”.