The Hidden System That Stops Planes From Hitting Mountains

Koppu on Instagram: "RENU-G is the acronym for GPWS (Ground Proximity Warning System). GPWS in the Airbus A320 consists of five basic modes, and each letter in RENUG represents one of those modes: R – Mode 1: Excessive rate of descent E – Mode 2: Excessive terrain closure rate N – Mode 3: Altitude loss after takeoff or go-around with landing gear and flaps (also known as negative rate of climb) U – Mode 4: Unsafe terrain clearance when not in landing configuration G – Mode 5: Too far below glide