MU-2
Flight Crew Private; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 2; Flight Crew Total 1269; Flight Crew Type 400
Distraction; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Human Factors; Aircraft
I was being vectored to the final approach course. The autopilot was not capturing the localizer or the GS. I was fixated on getting the autopilot to work with the autopilot and should have hand flown the course. I was below the GS and the Controller called for my altitude; I recognized I was below [the glide slope; but I] had the visual and called for the visual approach which was granted and I switched to Tower; landed Runway 30 no further incident.My corrective action is to be set up sooner for the ILS; and if the autopilot is not cooperating then recognize and switch to manual sooner.
MU2-26 pilot reported a malfunctioning autopilot distracted him enough that ATC alerted him to a low altitude situation on approach to APA.