Falcon 2000
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem; Flight Crew FLC Overrode Automation
Aircraft; Airspace Structure
Enroute to ZZZ. Was level at 16000 ft and direct to ZZZZZ when event started. ATC cleared us to descend via ZZZZZ1 arrival. I identified [the] lowest altitude 9000 ft at ZZZZZ2. Dialed in 9000 ft and engaged VNAV.The descent cue came down shortly and autopilot captured VNAV and started its descent. Everything looked normal to me. Crossing altitude at ZZZZZ is 15000 ft. And we had the pink 15000 displayed on PFD (Primary Flight Display) as a restriction. However we crossed below 15000 ft prior to ZZZZZ without me noticing. The PIC called out STOP. By the time I realized what was happening we were 700-800 feet low. I disconnected the autopilot and corrected back to 15000 ft. ATC told us to check our altitude the Minimum Vector Altitude he said was 14400 ft. Rest of flight was uneventful.I have flown the Falcon for years. I feel totally comfortable with using the VNAV function. I have never seen the autopilot do this before. During our debrief of the event we agreed everything was set up correctly and we had the right indications. However I know my faith in the automation caused me to let my guard down. I should have caught the descent below 15000 ft immediately. This was completely my mistake. The PIC was off getting the latest ATIS as I set it up.
We were on ZZZZZ1 arrival. We were at 17000 feet and were asked to descend to 16000 feet overhead traffic. While we were descending we were cleared to descend via arrival. I went off #1 radio to pick up ATIS on #2. I advised PF (pilot flying) of such and it was acknowledged. Once I came back on radio #1 I saw altitude lower than crossing restriction over ZZZZZ intersection. VNAV was active but didn't stop descent below restriction. As we corrected; ATC called low altitude alert. We corrected and nothing else was said.
Falcon 2000 flight crew reported that during descent the autopilot failed to capture the preselected altitude.