THE ACFT DIVERTED FROM SCOTTSDALE AZ TO A FLT COURSE TO SEDONA BECAUSE OF THUNDERSTORMS & HIGH WINDS AT SCOTTSDALE, BUT AFTER A RADIO CONVERSATION WITH SCOTTSDALE TWR, THE PLT DECIDED TO REROUTE TO LAND AT SCOTTSDALE. THE PLT DID NOT READ BACK THE WEATHER CORRECTLY TO SCOTTSDALE TWR. AFTER DESCENDING IN RAIN AND TURBULENCE, THE PLT REPORTED TO SCOTTSDALE AT1857 THAT 'WE THINK WE HAVE THE ARPT AT NINE O'CLOCK.' THE PLT WAS CLEARED TO MAKE A VISUAL APPROACH TO RWY 21. THE TWR NEVER ESTABLISHED VISUAL CONTACT WITH THE ACFT & WAS UNABLE TO MAKE FURTHER RADIO CONTACT THE LAST RECORDED RADAR CONTACT SHOWED THE ACFT AT 2200 FT DESCENDING, 2 MILES FROM SCOTTSDALE ON A BEARING OF 075 DEGREES. THE ACFT CONTACTED THE GROUND LEFT WING & NOSE LOW IN A LANDING CONFIGURATION ON A HEADING OF ABOUT 300 DEGREES. THE ACFT SLID ABOUT 770 FT, LOSING THE ENGINES, WINGS & LANDING GEAR BEFORE STOPPING. A POST ACCIDENT EXAMINATION OF THE WRECKAGE SHOWED NO SIGNS OF PRE-IMPACT CONDITIONS THAT WOULD HAVE AFFECTED NORMAL OPERATIONS.