New head-up display (HUD) technologies based on liquid-crystal display (LCD) scanning techniques promise to clear the way for smaller, lighter and more reliable hardware that will be capable of providing brighter images and new capabilities, according to manufacturers.

Makers are planning to move away from traditional cathode ray tube (CRT) projection techniques toward devices based on the LCD technology, which will mean less wieldy projection equipment installed in the cockpit and a crisper HUD picture.

Using technology similar to a digital media projector, an LCD HUD eliminates the high-intensity CRTs in today’s systems, which are heavy, bulky and inherently hot-running and require high- voltage power supplies.

By replacing the vacuum-tube CRT and its power supply with an LCD design manufacturers hope to bring about a significant increase in overall reliability, along with sharper pictures and improved gray-shade presentation in bright ambient light, which is important for viewing images supplied by enhanced-vision system (EVS) sensors.

Prices for LCD-based head-up displays are expected to remain about the same as those for current CRT-derived equipment but would likely start to drop once the technology has been on the market for a while, say experts.

“The [reduced] heat and size of LCD HUD are two of the major advantages of the technology,” explained Ken Snodgrass, director of marketing for avionics manufacturer Honeywell. “But where LCD really outdoes CRT is in brightness.” The power output of CRT is very high compared with LCD, and LCD displays are starting out with the same brightness that it has taken years to achieve with CRTs, he said.
Honeywell and Kollsman have teamed to develop a new HUD system for FedEx that uses LCD projection technology. The systems will be certified and installed on FedEx’s fleet of widebody aircraft, including the Boeing MD-10 and MD-11 and Airbus A300 and A310. The first aircraft certification, on an MD-10, is expected in next year’s fourth quarter.

This was the first major contract awarded to Honeywell for such systems and, said Snodgrass, will lead to an acceleration of the company’s LCD HUD design activity. By moving away from traditional CRT-based HUDs, he said, the company will be able to develop systems that are much smaller and lighter than CRT-based HUDs.

Thales, meanwhile, recently delivered the world’s first LCD HUD, to Airbus, which is scheduled to start flight testing this month aboard an A340-600. Airbus has selected the Thales digital HUD system for the A380 double-decker, which uses the same LCD scanning techniques. Future capabilities of the A380 HUD, said Thales, will include enhanced vision, synthetic vision and surface guidance system for better taxi awareness.

Rockwell Collins Flight Dynamics is also developing LCD HUD technology for civil airplanes. Embraer and Flight Dynamics are developing a dual head-up guidance system (HGS) for the Embraer 190 under a $60 million contract from launch customer JetBlue Airways. The Rockwell Collins Flight Dynamics HGS-5600 HGS included in the contract uses LCD-based technology for enhanced image quality and improved reliability.

So far, HUDs have not been widely used except on the largest business jets because of their size, weight and cost. LCD, say advocates, is a key to reducing size, which in turn will allow more airplanes to be fitted with HUD.

CMC Electronics, a maker of enhanced-vision sensors and owner of low-cost HUD manufacturer Flight Visions, has been working on LCD-based HUD designs that the company has said could be fitted in midsize or smaller business jets someday. For the time being, however, CMC appears to be more focused on military HUD development.