Cessna Citation Undifferentiated or Other Model
Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 75; Flight Crew Total 23600; Flight Crew Type 900
Situational Awareness; Human-Machine Interface
Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Human Factors; Chart Or Publication
RNAV 21L approach PDK airport. The flight crew made a mistake interpreting the approach plate. There was a visual step down point and we descended early to MDA 1;500 feet. A note on the plan view we missed briefing on. (LNAV only note Number 2 fix SEDOY was a visual descent point on the chart required 1;780 to cross for LNAV ONLY). The MDA LNAV for this approach was 1;500 feet MSL. We did have ground contact before MDA. PDK tower advised altitude alert which alerted the crew. A better review of approach plate on iPad will helpful.
The flight crew misinterpreted the approach plate and made a descent to the MDA too early during the RNAV Y 21L Approach into PDK. There was a visual descent point at which descent to the MDA would have been allowed; but this was overlooked and the flight crew descended the aircraft to the MDA of 1;500 feet MSL prior to this point. The flight crew had established visual ground contact prior to reaching MDA and prior to the visual descent point. PDK Tower gave us an altitude alert which alerted us to the issue and reason for further review upon landing.
Citation flight crew reported descending early on RNAV approach and receiving a low altitude alert from ATC.