Definition
A computer-generated three-dimensional depiction of the terrain, obstacles, and surrounding environment ahead of the aircraft, displayed on the primary flight display. The image is built in real time from an onboard terrain database combined with the aircraft's GPS position, attitude, and heading, giving the pilot a clear view of what is outside even when actual visibility is poor.
Plain English
A picture on the cockpit screen that shows what the world outside the aircraft looks like — hills, mountains, runways, and obstacles — drawn by the computer using stored map data and the aircraft's position. It looks similar to a video game view of the terrain ahead.
Context Anchor
Seen in discussions of Synthetic Vision Systems, especially on instrument displays during approaches, night flying, or flight in clouds.
Derivation
Synthetic comes from the Greek synthetikos, meaning 'put together' or 'constructed.' The image is not a real camera view — it is constructed by the computer from stored data, which is why it is called synthetic rather than real or actual.
Why Pilots Care
It improves terrain awareness and reduces the chance of controlled flight into terrain when outside visibility is poor.
Grounding Statement
If the airplane is in cloud, the display may still show a computer-made view of hills or a runway ahead based on the aircraft’s known location and stored data.
Intuition Check
Do not assume this is a real-time camera view. “Synthetic” means the image is computer-built from data, so it can be very useful but only as accurate as its data and inputs.
Example Sentence 1
Flying the approach in heavy haze, the pilot glanced at the synthetic terrain image and clearly saw the ridge to the north of the airport.
Example Sentence 2
Even in heavy rain at night, the synthetic terrain/vision image gave the crew a clear picture of the airport environment on final approach.