LHT’s Airtrack map program offers pax a pilot’s-eye view

 - December 18, 2007, 7:41 AM

Lufthansa Technik has completed the first installation of an unconventional moving-map system on an Air Berlin Boeing 737 and expects to carry out the first installation on a VIP aircraft, a Europe-based Boeing Business Jet, early next year.

Lufthansa Technik’s Airtrack, introduced at last month’s NBAA Convention, can provide multiple two- and three-dimensional views of the airplane’s location and flight path, with topographic views of the terrain below based on satellite imagery. LHT developed the system in partnership with TEAC, which provided the software and the terrain database. LHT, which developed the hardware, manufactures the system and provides product support.

Installation is straightforward, according to the manufacturer. Airtrack was designed as a form-and-fit replacement for the Airshow 420 system: appropriate documentation, including a supplemental type certificate, is required, but the physical installation involves swapping the boxes, a relatively straightforward procedure, LHT officials said.

Siegfried Olivo, Air Berlin’s technical director, said that the carrier switched to LHT’s Airtrack because it could not modify the existing Airshow moving-map system or use it to bring company activities to the attention of passengers.

“The biggest advantage of the new system is that we have direct control over programming,” he elaborated. “That is not the case in the existing system, where it could take a couple of months from developing a spot to showing it. We heard about the new system from LHT and realized that it might be an opportunity to give more information to passengers.”

Bernhard Conrad, senior v-p of LHT’s completion center and head of the approved design organization, said the system is readily customizable by the end user employing simple tools and simple languages such as HTML. It offers traditional flight and passenger information, with automated connecting gate and arrival information so the crew does not have to announce it. And it can be used as a medium for safety videos, advertising and boarding music.

Position, temperature, speed and time to destination is output from the flight-deck system, which has GPS input, to the single box housing the Airtrack system and from there to the existing monitors. A geographic information system database generates two- and three-dimensional maps from the 2-D satellite imagery at resolutions down to one meter per pixel. The maps are presented in various formats, including simulated cockpit windshield and cabin window views and various chase-plane perspective views, which can have the current track or bearing and time or distance to destination overlaid.

Andrew Muirhead, chief engineer in LHT’s innovation center and, according to Conrad, the father of the system, said Airtrack comes with the core software with map and basic functionality, then the airline can enlist the tools supplied to define the fonts used and events such as when video clips and ads appear. “You could highlight Vienna as a destination when you were overflying the city,” he suggested.

The terrain database covers the entire globe at a resolution of 3,360 feet (1,024 meters) per pixel and the continents at higher resolutions, Muirhead said. The resolution for views shown on the passenger screens can be restricted by legal requirements: “At one meter per pixel where you can see houses and streets we are limited in the areas we can show,” he said.

System Components

The system combines a Pentium processor with a powerful graphics card and a toughened hard drive fastened to shock mounts to prevent damage on landing and sealed against temperature and humidity, Muirhead said.

Airtrack uses the Windows 2000 operating system, so avoiding system crashes was one of the big challenges, Muirhead said.

“There are safety nets to keep an eye on what processes are going on involving the operating system so it doesn’t get in a corner where it will crash,” he said. “In fact, there are both software and hardware watchdogs so the software monitors itself, and if it wants to crash it will reset automatically. At the same time, the hardware watchdog monitors the operating system, so if the software locks up, the hardware will restart it.” Self-recovery in the event of a computer crash was one of the certification requirements, Conrad added.

The basic system broadcasts the same data to all monitors, but there is a connector on the front of the box for a second box that can be used to stream data to the passengers so that they would be able to select their own views on an interactive system, Muirhead said.

In fact, Airtrack provides the aircraft with 80 gigabytes of storage capacity, the equivalent of 40 hours of mpeg video. So the system could serve as the foundation for a basic in-flight entertainment system, although, “There is no multi-channel facility to provide different languages; you could have only one audio track and one additional language subtitled,” Muirhead said.

All 3-D displays are turned off when the airplane is below 5,000 feet, said LHT innovation engineer Gerko Wende. “We simulated displays at lower levels with Air Berlin and the cockpit view was too alarming in a strong crosswind,” he said.

The system has pre-defined sequences that it selects automatically and shows in various stages of flight, such as when the airplane is at the gate and during taxi out, departure, cruise, approach and taxi to the gate. The selection responds to the airplane’s speed over the ground. In Air Berlin’s case, the taxi sequence starts when the speed exceeds five knots and switches to the departure sequence at 70 knots and the cruise display at 350 knots.

The mid-September demonstration flight revealed some quirks to be ironed out. The cockpit view, which pans from right to left and back, appeared slightly jerky, for example. Wende said this was a function of the prioritization strategy: the maximum processor load allowed is 35 percent, and priority is given to the graphics processor, leaving the card processing data from the flight deck with too much work to do. “We have to figure out the balance between the Arinc card and the graphics processor,” he said.

The quality of the output, meanwhile, is limited by the requirement to conform to the system it is replacing. “We are sticking to the existing provision, which is a single analog NTSC [national television system committee] output,” Wende said. “We have a hardware port to stream data over an Ethernet to an IP-based system, and we have a high-resolution RGB output for VIP aircraft, plus a special output using three coaxial cables that provides near RGB quality. But the Air Berlin system uses interlaced NTSC, and all current systems are NTSC-based.”