WHEN THE PLT ARRIVED AT THE DESTINATION ARPT, THERE WAS CONSTRUCTION ON THE RWY, ABOUT 2500 FT FROM THE APCH END. HE CONTACTED UNICOM & WAS ADVISED THAT THE RWY WAS CLOSED, BUT WAS TOLD HE COULD LAND ON THE GRASS BESIDE THE RWY. THE PLT RESPONDED THAT THE GRASS AREA WAS TOO ROUGH. HE STATED, 'I THINK I CAN LAND ON THE RWY AVAILABLE, THERE SEEMS TO BE ENOUGH LENGTH THERE.' SUBSEQUENTLY, THE ACFT WAS OBSERVED APPROACHING RWY 8 AT AN ESTIMATED 30 FT AGL WITH THE GEAR & FLAPS DOWN. REPORTEDLY, THE POWER WAS INCREASED, THE NOSE ASSUMED A CLIMB ATTITUDE & THE GEAR WAS RETRACTED. THE ACFT THEN ROLLED LEFT, DOVE TO THE GROUND & CRASHED. AN EXAM OF THE WRECKAGE REVEALED NO EVIDENCE OF A PREIMPACT PART FAILURE OR MALFUNCTION. AN EVALUATION OF THIS MAKE & MODEL OF ACFT REVEALED THAT WHEN THE CG APPROACHED THE AFT LIMIT, & THE FLAPS WERE EXTENDED, THE ACFT HAD REDUCED YAW & ROLL CONTROLLABILITY DURING POWER ON STALLS. THE FLAPS WERE FOUND FULL DOWN.