THE PLT RECEIVED A WEATHER BRIEFING PRIOR TO DEPARTURE FROM SCOTTSDALE. HE ENCOUNTERED IMC SHORTLY AFTER TAKEOFF. THE FLT PROGRESSED UNEVENTFULLY UNTIL IN THE VICINITY OF COLORADO SPRINGS WHEN THE PLT RPTED A PROBLEM WITH HIS DIRECTIONAL GYRO. THE PLT DESCENDED FROM 19000 TO 8000 FT IN CLOUDS, ICING CONDITIONS AND SNOW. TWENTY FIVE MINUTES AFTER THE PLT BEGAN THE DESCENT HE RADIOED THAT HE HAD AN ENGINE PROBLEM AND WAS 'GETTING ALOT OF SURGING.' TWO MINUTES LATER ALL RADIO AND RADAR CONTACT WAS LOST WITH N6917R. EXAM OF THE ACFT ENG AFTER THE ACCIDENT REVEALED NO EVIDENCE OF A MECHANICAL MALFUNCTION OR MECHANICAL FAILURE THAT WOULD HAVE PREVENTED NORMAL ENG OPERATION. DUR TO DAMAGE SUSTAINED IN THE IMPACT, THE POSITION OF THE ALTERNATE AIR DOOR COULD NOT BE DETERMINED. EXAM OF THE WRECKAGE REVEALED THE ACFT IMPACTED THE GND IN A RIGHT WING LOW, NOSE LOW ATTITUDE AT A HIGH RATE OF SPEED. THE FLT WAS DESTUNED FOR BROOMFIELD (JEFFCO ARPT) CO. BUT DIVERTED TO ARAPAHOE ARPT WHEN THE ENG PROBLEM OCCURRED.