Lancair Undifferentiated
Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 35; Flight Crew Total 1375; Flight Crew Type 30
Distraction; Situational Awareness; Workload
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance
Human Factors
Chain of events:1. How problem arose: Had to disconnect autopilot to comply with speed restriction. During ILS clearance/intercept stage and pre-landing checklist; FMS was incorrectly loaded with altitude bug. 2. Contributing factors: high single pilot workload with fairly new system. Programming complexity led to loss of Situational Awareness. How discovered: ATC alerted of low altitude. 3. Corrective action: applied power and regained altitude within seconds. Human performance considerations: 1. Perceptions: Thought FMS altitude bug was set correctly.2. Judgments: Checked altimeter and applied power immediately to regain 300 feet to proper altitude. 3. Inactions: Failure to program FMS altitude bug and failure to recognize premature descent prior to FAF passage. 4. Factors affecting the quality of human performance: High workload and relatively low time in type. First experience with specific speed restrictions. Solution: spend more time practicing high workload situations with various speed configurations under simulated hood with experienced safety pilot and avoid hard IFR until more experienced with aircraft.
Lancair pilot reported an excursion from altitude and ATC issued a low altitude alert during ILS approach.