Lufthansa has conducted satellite navigation flight trials with a Boeing 737 equipped with a terrain awareness and warning system (TAWS) upgraded with global positioning system (GPS) functionality.

The German airline, which has developed the retrofit with Boeing and Honeywell, equipped a single 737-500 with the system which comprises an additional plug-in card in the aircraft's onboard computer allowing the aircraft to use more precise position information via GPS. "We installed a new variant of Honeywell's Enhanced Ground Proximity Warning System computer with a GPS sensor card built into it. This in turn enables a more accurate terrain avoidance function on the TAWS as well as providing a highly accurate sensor for navigation purposes," says Lufthansa.

"This is a highly cost-efficient solution with minimum ground time and cost to install." The carrier claims the retrofit costs a quarter of the price of a GPS multi-mode receiver installation.

Flight trials were performed in late March and April. The aircraft flew to Munster Osnabrück airport where it conducted four simulated landings and an actual landing using the satellite navigation system. Position accuracy checks were performed on the runway after which the aircraft tested the terrain warning functions over mountains near the city of Kassel, says Lufthansa.

"We achieved even better results than expected," says the airline. German LBA and US Federal Aviation Administration certification is expected by the middle of the year.

Lufthansa says the system is suitable for retrofit on "thousands of aircraft" equipped with a basic flight management computer, including 737s and Boeing MD-80s. The German carrier plans to modify its 68 737s when the change is certificated. It does not operate MD-80s and is seeking a partner airline to support certification for the type.


Source: Flight International