Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument
Flight Crew Last 90 Days 70; Flight Crew Total 17500; Flight Crew Type 2000
Situational Awareness
Inflight Event / Encounter CFTT / CFIT
General None Reported / Taken
Human Factors
During descent from mountainous terrain; I descended too early and passed within less than 300 feet AGL of a ridge. This was an unintentional excursion during descent from mountainous terrain into the valley floor. I was leaving a 1000 foot AGL cruise to a planned 1500 foot cruise in lower terrain. During my descent I noticed my radar altimeter decreasing in altitude; I expected it to indicate approximately 300 to 400 feet passing the ridge; but I noticed it actually indicate a low of just above 200 prior to starting its climb back up to indicate approximately 2000 AGL. I never intended to be below 300; but the aicraft indications did show that I was below 300.
AS350 Pilot reported starting a descent too early and passing within less than 300 feet of a ridge.