This video is a re-creation of an actual accident involving a Bell 407 helicopter on an EMS mission. On the left is a display of the terrain as would have been seen outside of the helicopter windscreen…except the actual flight was at night with some patchy ground fog, preventing the pilot from ‘seeing’ the terrain. On the right is the cockpit display of the terrain that could have been available to the pilot if the helicopter had been equipped with an Enhanced Ground Proximity Warning System (EGPWS). The terrain display format uses the following coloring scheme:
Notice how the color-coded terrain can help the pilot assess the situation very early – the potentially dangerous terrain is already highlighted in red. The color pattern turns to solid colors when EGPWS detects a terrain conflict and issues an alert. As the aircraft progresses, 35 seconds prior to impact, you will see a portion of the terrain display transition to solid yellow, accompanied by the "Caution Terrain" aural annunciation. Also note that when the caution alert occurs, the terrain display automatically zooms in closer on the threat, helping the pilot more quickly assess the danger. Continuing on, 20 seconds prior to impact, you will see a portion of the terrain display transition to solid red, accompanied by the "Warning Terrain" aural annunciation. This series of annunciations supported by the terrain situational display in the cockpit provides the pilot ample time to correct the flight profile to avoid the terrain.