Narrative:

Participant in airshow with aerobatic aircraft. Climbed to 5000 ft AGL to start air show. Waivered airspace in effect at XX00 local. Altimeter has to be set on AGL to do aerobatics for safety. No time if set on MSL to do calculations about how high above ground when nose pointed straight at ground! Checking later realized waiver was to 5000 ft MSL, oops! Sorry I'm professionally human! Ps: reason start so high -- stopped the propeller to do aerobatics at deadstick landing.

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Original NASA ASRS Text

Title: PLT OF AN AEROBATIC SMA PENETRATED TCA (CLASS B) AIRSPACE WHEN MANEUVERING AT THE TOP OF AN AIRSHOW WAIVER ALT BECAUSE HE SET, AS IS CUSTOMARY, ACFT ALTIMETER TO ZERO ON GND.

Narrative: PARTICIPANT IN AIRSHOW WITH AEROBATIC ACFT. CLBED TO 5000 FT AGL TO START AIR SHOW. WAIVERED AIRSPACE IN EFFECT AT XX00 LCL. ALTIMETER HAS TO BE SET ON AGL TO DO AEROBATICS FOR SAFETY. NO TIME IF SET ON MSL TO DO CALCULATIONS ABOUT HOW HIGH ABOVE GND WHEN NOSE POINTED STRAIGHT AT GND! CHKING LATER REALIZED WAIVER WAS TO 5000 FT MSL, OOPS! SORRY I'M PROFESSIONALLY HUMAN! PS: REASON START SO HIGH -- STOPPED THE PROP TO DO AEROBATICS AT DEADSTICK LNDG.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.