Light Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Multiengine
Flight Crew Last 90 Days 60; Flight Crew Total 15000; Flight Crew Type 2800
Confusion; Situational Awareness; Workload
Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Unstabilized Approach; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance; Flight Crew Took Evasive Action
Weather; Procedure; Airport
Descending in IMC heading direct to DBL; talking to DEN center.  In FMS/NAV mode cleared down to 13;400. DEN assigns 340 heading changed to HDG Mode for turn to 340; then DEN then issued a right turn to 320; questioned the direction; DEN corrected to Left to 320. Handed off to Aspen Approach who issued a lower altitude and Left turn to 2xx degrees. Approach issued a Left turn to 180 to intercept Runway 15 LOC/DME maintain 12;900.  Turned to 180 heading with HDG bug; First Officer and APPR notified me about the same tine that I was east of course and what my intentions were. Corrected to get back on course turned with HDG bug 180 to intercept inbound again. LOC came alive I turned back to 150 heading too soon to intercept; APP queries me 'correcting.' Navigation instruments where set with White (FMS) on left and Green (LOC) on the right. After becoming established inbound; Approach notified us of a cloud moving through at approximately the MAP point. Visual contact was made prior to MAP; as we passed through cloud decent had started; First Officer called MAP. Visual on airport and runway was made. Tower cleared us for a left visual circle to Runway 15 as we where high for landing at 9;900.  I did not think a left (east) circle would work to stay VMC; so I told First Officer we would do a right (west) circle back to Runway 15; First Officer notified the Tower.  Brought the flaps up to 8; possibly thinking of missed and climbing to 14;000. In doing right circle; I over flew a Noise Sensitive area and received a Terrain Warning while over flying a ridge abeam approach end of Runway 15. Descended after passing the ridge for a right base turn to Runway 15. Speed was at .65 on AOA; asked First Officer how it looked he said its tight; over flew center line turning right to Runway 15; continued turn back to Runway 15. During right turn .8 on AOA was hit which sent an audible stall warning signal; speed had already increased decreasing AOA to .7 then to .6 AOA.  Aircraft landed with no further issue.Numerous errors where made here; the largest was attempting to continue with a poorly set up approach. Inbound course deviation occurred due to switching from NAV mode to HDG mode when initial vectors where being given and not confirming that NAV mode was selected for the approach course intercept using the FMS when Approach Clearance was issued.  The decision to circle to the right should have been to start the missed approach in the right turn and climb to 14;000.  My thinking was I could remain VMC and knew that after the ridge line the terrain dropped back down. What I did not realize was that the ridge extended as far to the east as it did; which delayed Runway 15 coming back into sight which led to over shooting Runway 15 center line. After the initial course deviation the mindset should of have gone to prepare for the missed not continue to force the landing. Given the surrounding terrain and weather; electing to go missed initially and come back in on the approach would have been the optimal decision. Briefed approach being flown with FMS not Green should of been done thus reviewing the confirm NAV is engaged step which did not occur.
A corporate pilot on the ASE Runway 15 LOC/DME approach remained in the FMS Mode off course and after clearing a cloud high at the MAP started a missed approach; but changed to a right circling approach VFR over a noise sensitive area and toward terrain.