Helicopter EGPWS in Testing

Sikorsky Aircraft and Honeywell have completed 42 hours of flight testing of the first enhanced ground proximity warning system designed specifically for helicopters.

The team hopes to achieve FAA certification before the end of the year, and to make the Mark XXII EGPWS available for new and used Sikorsky S-76 helicopters by early 2001.

"Helicopter pilots will find it greatly enhances their situational awareness, thus improving operational safety in low visibility with less workload," says Sikorsky civil programs VP Tommy Thomason.

Flight-testing was conducted near Asheville, North Carolina, with participation from the FAA, NASA, the U.S. military, the National Rotorcraft Technology Centers, and the Rotorcraft Industry Technology Association.

Improvements over earlier systems include the ability to display terrain and obstacle information on EFIS or weather radar displays, so pilots can immediately determine if towers and other obstacles represent a threat.

Sikorsky plans to offer the Mark XXII EGPWS on its entire product line. The unit also features tail strike and bank angle alerts, with auto-rotation altitude and landing gear position awareness reminders.

In normal mode, the system provides a 30-second terrain and obstacle look-ahead caution, with a 250-foot terrain clearance floor minimum.

The enhanced low altitude mode reduces look-ahead caution time to 18 seconds, and the terrain clearance floor to a 200-foot minimum.

Additional features include "Peaks" and "Geometric Altitude" capability. Peaks provides a digital elevation for the highest and lowest displayed terrain, as well as a depiction of water and shoreline.

Geometric Altitude uses GPS, radar altimeter and air data computer information to eliminate errors due to temperature extremes, non-standard pressure altitude and altimeter miss-sets

By Paul Richfield