DISPUTED PERFORMANCE ALT AT AN AIRSHOW.

Narrative

DURING MY STANDARD AIRSHOW AEROBATIC ROUTINE; I INITIALLY ENTER THE AEROBATIC 'BOX' WITH MY ACFT'S WINGS LEVEL AT APPROX 1100 FT AGL PLUS OR MINUS ABOUT 25 FT FROM THE R REAR AT APPROX A 30 DEG ANGLE TO THE SHOW LINE; HEADING TOWARDS SHOW L AND THE AEROBATIC BOX. LATER NEAR THE END OF MY STANDARD AIRSHOW AEROBATIC PERFORMANCE; I APCH THE AEROBATIC BOX FROM SHOW REAR; AT SHOW CTR; WINGS LEVEL AT APPROX 1100 FT AGL PLUS OR MINUS ABOUT 25 FT. AFTER OVERFLYING THE CROWD; WINGS LEVEL; AND THEN EXITING THE CROWD LINE I ENTER THE AEROBATIC BOX AND INITIATE A VERT CLB TO VERT ROLLS. I HAVE PERFORMED THESE SAME APCHS TO AND SUBSEQUENT MANEUVERS DOZENS OF TIMES OVER THE PAST 2 YRS AT FAA MONITORED AIRSHOWS WITHOUT QUESTION; OR OBJECTION FROM ANY OF THE ON-SITE FAA MONITORS. DURING MY SHOW PERFORMANCE ON OCT/SAT/00; BEGINNING AT APPROX XA30 LCL AND ENDING APPROX XA45 LCL; THE FAA MONITORS WERE; ACCORDING TO THEIR OWN SUBSEQUENT COMMENTS; LOCATED IN AN AREA ABOUT 200-300 FT TO THE R OF THE FURTHEST R FORWARD CORNER OF THE CROWD LINE; AS ONE FACED THE SHOW. IN THIS POS THERE WAS A 14 FT HIGH SEVERAL HUNDRED FEET LONG JET BLAST BARRIER BTWN THEMSELVES AND THE ENTIRE CROWD AND ACFT RAMP AREA. AS SUCH AND FROM THIS POS THEIR VIEW OF THE CROWD; STATIC DISPLAY RAMP; AND MOST OF THE BUILDINGS ADJACENT TO THE RAMP WHICH COULD HAVE GIVEN PERSPECTIVE TO THEIR VISUAL CUES WAS NEARLY COMPLETELY BLOCKED. IMMEDIATELY AFTER MY PERFORMANCE THE HEAD FAA MONITOR APCHED ME TO INFORM ME THAT IN HIS OPINION; AND THAT OF THE OTHER MONITORS; THEY BELIEVED I HAD BEEN BELOW MY ALT OF 500 FT AGL WHILE OVERFLYING THE CROWD DURING THE ABOVE REFED MANEUVER APCHS. SUBSEQUENTLY AND ON INQUIRY MADE BY THE FAA MONITORS; THE ATC SPECIALIST PRESENT IN THE SEYMOUR-JOHNSON AFB CTL TWR ESTIMATED MY HT TO BE 1500 FT AND 1700 FT AGL RESPECTIVELY DURING MY 2 OVERFLTS OF THE SPECTATOR CROWD. ADDITIONALLY; A VIDEO TAPE OF MY PERFORMANCE TAKEN FROM THE FRONT R CORNER OF THE CROWD LINE; AS WELL AS OTHER OFF DUTY MIL CTL TWR ATC SPECIALISTS AND AN OFF DUTY FAA DESIGNATED WAIVERED AIRSPACE MONITOR LOCATED NEAR THE FRONT CTR OF THE CROWD AT THE TIME THE CROWD OVERFLTS IN QUESTION OCCURRED; ALL VERIFY THAT I WAS AT A SAFE ALT DURING THE CROWD OVERFLTS. AFTERWARD; HAVING VIEWED THE AIRSHOW AREA FROM THE LOCATION THE HEAD FAA MONITOR STATED THAT THE MONITORS WERE IN WHEN THEY OBSERVED MY PERFORMANCE; IT IS MY OPINION THAT IT WOULD BE DIFFICULT; OR IMPOSSIBLE FOR SOMEONE(S) WHOSE VIEW OF MOST OF THE VEHICLES; PERSONS; AND STRUCTURES ON THE GND WAS NEAR COMPLETELY BLOCKED; TO ACCURATELY JUDGE THE HT AGL OVER AN AIRSHOW CROWD OF A SMALL ACFT TRAVELING AT HIGH SPD. THIS WOULD BE PARTICULARLY TRUE IF; AS THE FAA HEAD MONITOR STATED; THOSE INDIVIDUALS WERE UNAWARE THAT SUCH AN APCH TO THE AEROBATIC BOX; AS THE ONES IN QUESTION ABOVE; WAS ABOUT TO OCCUR AND WERE SURPRISED BY ITS OCCURRENCE.