THE PLT INITIATED A NORMAL TAKEOFF & CLIMB UNTIL THE ACFT WAS OVER THE DEPARTURE END OF THE RWY AT ABOUT 150 FT AGL WITH THE LANDING GEAR & FLAPS RETRACTED. THE ACFT THEN ROLLED RAPIDLY INTO A STEEP LEFT BANK, TURNED ABOUT 180 DEG & CLIMBED TO APRX 250 FT AGL. AS THE ACFT ROLLED TO A WINGS LEVEL ATTITUDE, THE NOSE WAS SLIGHTLY ABOVE THE HORIZON. THE ACFT REMAINED IN THAT POSITION MOMENTARILY, THEN QUICKLY ROLLED INTO A STEEP LEFT BANK. AFTER ABOUT ANOTHER 30 DEG OF HEADING CHANGE, THE ACFT ROLLED OVER-THE-TOP INTO A RIGHT SPIN. REPORTEDLY, THE SPIN WAS STOPPED AFTER ABOUT 3 TURNS, BUT BEFORE RECOVERY, THE ACFT STRUCK THE GROUND IN A NOSE DOWN, RIGHT WING DOWN ATTITUDE. AFTER INITIAL IMPACT, THE ACFT CONTINUED INTO A CHAPEL BUILDING & BURNED. NO PREIMPACT PART FAILURE OR MALFUNCTION WAS FOUND. THE PLT POSSESSED A WAIVER TO FLY WITH AN AMPUTATED LEG. THE ACFT WAS MODIFIED SO THAT HE HAD FULL CONTROL OF THE RUDDER WITH 1 LEG.