Higher performance head-up

The latest incarnation of BAE Systems’ Waveguide head-up display (HUD) technology is the LiteWave®, intentionally designed for installation on a wide range and size of commercial and military aircraft. Ed Hill visited the company’s Electronic Systems division in Rochester to see its unveiling.

Head-up display (HUD) systems have a long history in the world of military aircraft but are a more recent development in the field of commercial aviation. Designed to display important information for the pilot directly within their line of sight, without having to continually refer to dials or screens mounted lower down in the cockpit, the technology helps to improve a pilot’s overall situational awareness, reduce workload and fatigue and provide instant flying data, such as heading, altitude, airspeed and an artificial horizon, while the pilot can still look ahead out of the window. 

Now BAE Systems has launched a revolutionary new ‘LiteWave’ HUD intended for installation in commercial and military aircraft in platforms ranging from long range commercial jets and transporters to regional aircraft, business jets and even smaller.

Born out of the Open Flight Deck Project, a consortium-led initiative involving industrial and academic partners – BAE Systems, Rolls-Royce, GE Aviation and the universities of Coventry and Southampton – to create an advanced, more universal and upgradable pilot/aircraft interface, LiteWave is the latest application of BAE Systems’ patented  digital Waveguide technology – initially developed for its military LiteHUD variant – that dispenses with much of the optics (lenses, mirrors and prisms) and electronics of a traditional HUD to produce a system not much bigger than a laptop that can be mounted above the pilot’s head in a broad range of cockpit settings.

“Our engineers have created a digital display that is smaller, lighter and uses less power than any other head-up display,” explains Lee Tomlinson, director of HUD products at BAE Systems’ Electronic Systems. “It has the potential to revolutionise the market and make HUD technology far more accessible.”

In a traditional HUD, images are projected and enlarged onto a sheet of glass or ‘combiner’ by using complicated optics and electronics in a large assembly mounted on the cockpit dashboard. With LiteWave the image is projected within the laminated screen, stretched vertically and horizontally and reflected back to the pilot as easily viewable heads-up information.

“LiteWave represents a 70% reduction in size and weight of this kind of product compared to conventional HUDs, meaning it can be installed in cockpits where previously there would not have been the space,” adds Tomlinson.

BAE Systems has also patented a special overhead mounting assembly for LiteWave which means it can be installed without the use of time-consuming adhesives. What would normally take a whole day while the adhesives cure can now be achieved in around four hours.

“We consulted with the OEMs and airlines who were frustrated at how long it can take to install a HUD system. Our mounting mechanism means that from end to end the LiteWave, including levelling, only takes around four hours to install. That’s an 80% reduction in the time needed to fit a head-up display,” Tomlinson affirms.

A legacy of light

BAE Systems has a peerless history when it comes to developing HUD technology. Its site at Rochester, Kent has been producing systems since the early 1960s. In fact, the facility developed the first such system for the Royal Navy’s Blackburn Buccaneer fighter aircraft. Since then, it has produced more than 15,000 HUDs that are in service in more than 50 countries globally. The systems are employed on some of the most advanced modern military aircraft including the Eurofighter Typhoon, F-16 Fighting Falcon and F-22 Raptor.

In the superfast environment of a jet fighter HUD benefits seem obvious, but they are also wide ranging in the commercial environment, especially as aircraft avionics become more complex, flight times longer and skies and airports more congested.

Aside from the basic flying telemetry, the system can be used to project visual information from sensors in reduced visibility – an obvious benefit when taking off or landing – warning messages, air traffic control information and also importantly guidance when negotiating and taxiing busy airports.

“One of the applications we’ve developed is to help give guidance to pilots when they are taxiing in the fog,” states Tomlinson. “In that situation you can display guide information for the pilot that can prevent an aircraft leaving the runway and going onto the grass or soft ground which can be a very disruptive event at an airport.”

Stewart Penney, business development manager at BAE Systems Electronic Systems adds: “Commercial pilots fly to many different airports. Some may be simple on the ground but others, such as Paris Charles de Gaulle are very complicated, or pilots may be flying to a busy airport for the first time. Pilots getting lost at airports in situations like this are quite common and can cause major disruption to the network and flight schedules. It’s a problem the industry is aware of, so projected guidance from a system like LiteWave can be extremely beneficial to pilots in those circumstances.”

Eyes wide open

Tomlinson also explains that the LiteWave has improved clarity and the widest ‘Eye Motion Box’ on the market, meaning the pilot can make greater head and body movements away from the screen before they lose sight of the information. The developers have also significantly reduced the number of components in the system, not only reducing weight but also leading to greater reliability.

“We’ve managed an incredibly efficient use of componentry in order to achieve the LiteWave product,” Tomlinson asserts. “The clarity is fantastic compared to comparable systems on the market and the reduction in component count makes it very efficient and reliable. In effect, there is less to go wrong and that means the mean time between failure (MTBF) rate is greatly improved to 15,000 hours.”

BAE Systems estimates the LiteWave will be approximately 20% cheaper than competitor HUD systems - not just due to the initial acquisition cost, but also the through life maintainability and ease of installation. A further benefit is that the system has an open architecture thanks to its links with the Open Flight Deck programme.

“Some HUD vendors have devised bespoke interfaces which means their HUD systems will only work with other elements of their equipment, such as the display computers or sensors,” says Tomlinson. “Having an open architecture means the system is compatible with anything else on the marketplace that uses those common interfaces.”

So, it seems with the development of LiteWave, head-up displays will be a much more common sight in cockpits around the world. 

“We undertook flight safety testing at the end of last year which was very successful and we are now at the stage of taking it through to flight certification,” Tomlinson concludes. “We have enough data to be able to go to potential customers, ask them to try LiteWave on their platform, and if it performs as expected continue to full certification.”

To watch a video of the LiteWave system visit: https://www.youtube.com/watch?v=USwsy2kFvFg

www.baesystems.com