Description / Abstract: This MOPS defines a Helicopter Terrain Awareness and Warning System (HTAWS), Airborne System. The HTAWS is an alerting system intended to provide terrain and obstacle aural and visual alerts. It is designed to reduce the risk of Controlled Flight into Terrain (CFIT) accidents by providing increased situational awareness of the surrounding terrain and obstacles, mainly during the cruise phase in Visual Meteorological Condition (VMC) and in Instrument Meteorological Condition (IMC) under Instrument Flight Rules (IFR). HTAWS is not intended to be used as an aid for navigation.