THE PLT HAD BEEN ACTIVE IN ORGANIZING AN AIR SHOW, BUT WAS NOT CONSIDERED A PARTICIPANT. HOWEVER, HIS HOME BUILT ACFT WAS ON STATIC DISPLAY. ON THE 2ND DAY OF THE SHOW, THE CHAIRMAN OF THE EVENT GAVE HIM PERMISSION TO DO A FLY-BY. SUBSEQUENTLY, HE INITIATED A PASS DOWN RWY 23 AT AN ALTITUDE OF APRX 150 FT AGL. DURING THE PASS, THE ACFT BEGAN TO PORPOISE, MADE 2 OSCILLATIONS ABOUT THE LATERAL AXIS, THEN BEGAN TO DISINTEGRATE. WHILE STILL IN FLT, THE WINGS, FLAPS, VERTICAL STABILIZER, RUDDER, RIGHT HORIZONTAL STABILIZER & PARTS OF THE CANOPY SEPARATED. THE FUSELAGE THEN ROLLED SLIGHTLY TO THE RIGHT, CRASHED & BURNED. THE ACFT WAS NOT CERTIFICATED FOR AEROBATIC FLT. THE MANUFACTURER OF THE KIT (FROM WHICH THE ACFT WAS BUILT) RECOMMENDED THE CRUISE SPEED (VNO) BE 172 MPH & THE NEVER EXCEED SPEED (VNE) BE 210 MPH. THE ACFT'S AIRSPEED INDICATOR WAS CALIBRATED IN KTS & WAS MARKED WITH THE VNO & VNE AT 170 & 213 KTS (196 & 244 MPH), RESPECTIVELY. PSEUDOEPHEDRINE & CHLORPHENIRAMINE FOUND IN PLT'S URINE.