Lancair pilot reported an excursion from altitude and ATC issued a low altitude alert during ILS app...

Attributes
ACN	1614317
Time
Date	201901
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Lancair Undifferentiated
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 35 Flight Crew Total 1375 Flight Crew Type 30
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

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.

Original NASA ASRS Text

Title: Lancair pilot reported an excursion from altitude and ATC issued a low altitude alert during ILS approach.

Narrative: 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.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.