Honeywell has started flight tests of the industry's first enhanced ground proximity warning system for helicopter use. Tests of the Mark XXII EGPWS are being supported by Sikorsky, which is supplying an S-76B for the program. The new system should be certified by the end of the year. The EGPWS uses a database of terrain and obstacles and warns the crew if the helicopter's flight path will bring it too close to the ground or an obstacle. Compared to a fixed-wing EGPWS, the Mark XXII has a higher-resolution database for low-level operations, a tail-strike warning function and automated altitude awareness warnings during auto-rotation. Other features include a computer-monitored "geometric altitude," designed to eliminate altitude errors resulting from temperature extremes and miss-set altimeters.