Narrative:

My intention was to ride right seat and familiarize test pilot with aircraft, do a high speed taxi run, come back to hangar, remove cowling and inspect aircraft. Test pilot said system were not familiar to him, so during high speed taxi run, he kept throttle in and even as we lifted off I thought he was going to set aircraft down. We were then committed, so I assisted with airspeed callouts and radio work. I was not well prepared. A lower cowl inspection door came off (we surmise) and damaged the propeller. We made an emergency landing. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was a home built composite pusher pwred with a reciprocating engine. The reporter said this was the first planned test since construction was completed and was only to be a high speed taxi run. The reporter stated the airplane lifted off at high speed and at 3000 ft a cowling inspection door came off striking the propeller. The reporter said the door put several dings in 1 blade that caused an imbal and resultant severe vibration. The reporter said the landing was uneventful. The reporter stated the FAA has made no contact regarding this incident.

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Original NASA ASRS Text

Title: A HOME BUILT EXPERIMENTAL PUSHER ACFT IN CLB AT 3000 FT DECLARED AN EMER AND DIVERTED DUE TO SEVERE PROP VIBRATION CAUSED BY A COWLING INSPECTION DOOR DEPARTING THE ACFT STRIKING THE PROP.

Narrative: MY INTENTION WAS TO RIDE R SEAT AND FAMILIARIZE TEST PLT WITH ACFT, DO A HIGH SPD TAXI RUN, COME BACK TO HANGAR, REMOVE COWLING AND INSPECT ACFT. TEST PLT SAID SYS WERE NOT FAMILIAR TO HIM, SO DURING HIGH SPD TAXI RUN, HE KEPT THROTTLE IN AND EVEN AS WE LIFTED OFF I THOUGHT HE WAS GOING TO SET ACFT DOWN. WE WERE THEN COMMITTED, SO I ASSISTED WITH AIRSPD CALLOUTS AND RADIO WORK. I WAS NOT WELL PREPARED. A LOWER COWL INSPECTION DOOR CAME OFF (WE SURMISE) AND DAMAGED THE PROP. WE MADE AN EMER LNDG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A HOME BUILT COMPOSITE PUSHER PWRED WITH A RECIPROCATING ENG. THE RPTR SAID THIS WAS THE FIRST PLANNED TEST SINCE CONSTRUCTION WAS COMPLETED AND WAS ONLY TO BE A HIGH SPD TAXI RUN. THE RPTR STATED THE AIRPLANE LIFTED OFF AT HIGH SPD AND AT 3000 FT A COWLING INSPECTION DOOR CAME OFF STRIKING THE PROP. THE RPTR SAID THE DOOR PUT SEVERAL DINGS IN 1 BLADE THAT CAUSED AN IMBAL AND RESULTANT SEVERE VIBRATION. THE RPTR SAID THE LNDG WAS UNEVENTFUL. THE RPTR STATED THE FAA HAS MADE NO CONTACT REGARDING THIS INCIDENT.

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.