Narrative:

My instructor and I had just finished some aerobatic practice in an small aircraft biplane and were in the traffic pattern to do a few lndgs. I occupied the rear seat, my instructor was in the front. There was no other traffic in the pattern. I was flying the downwind leg approximately 3/4 of a mi from the runway. I was at 800 ft AGL (pattern altitude), 15 inches manifold pressure, and 110 mph. Abeam the approach end of the runway, my instructor pulled the throttle all the way back to simulate an engine failure. I began an immediate left descending turn to the runway at 100 mph. Turning to final, from my vantage point, looking out along the left side of the aircraft, it appeared to me that we were clearing the trees off the approach end of the runway, but that we would need power to make the runway itself. At that point my instructor advised me to add power, which I did. Almost immediately there was a jolt. We apparently hit the upper branches of a tree that was blocked by the nose to my line of sight. My instructor took control of the airplane and landed without further incident. There were no injuries but the airplane requires extensive repair. I was so intent on making a nice gliding turn to the runway, that I forgot the airplane's poor visibility characteristics. My attention should have been more evenly divided among all of the factors affecting the flight.

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Original NASA ASRS Text

Title: AEROBATIC ACFT CLIPS TREE ON APCH TO LNDG.

Narrative: MY INSTRUCTOR AND I HAD JUST FINISHED SOME AEROBATIC PRACTICE IN AN SMA BIPLANE AND WERE IN THE TFC PATTERN TO DO A FEW LNDGS. I OCCUPIED THE REAR SEAT, MY INSTRUCTOR WAS IN THE FRONT. THERE WAS NO OTHER TFC IN THE PATTERN. I WAS FLYING THE DOWNWIND LEG APPROX 3/4 OF A MI FROM THE RWY. I WAS AT 800 FT AGL (PATTERN ALT), 15 INCHES MANIFOLD PRESSURE, AND 110 MPH. ABEAM THE APCH END OF THE RWY, MY INSTRUCTOR PULLED THE THROTTLE ALL THE WAY BACK TO SIMULATE AN ENG FAILURE. I BEGAN AN IMMEDIATE L DSNDING TURN TO THE RWY AT 100 MPH. TURNING TO FINAL, FROM MY VANTAGE POINT, LOOKING OUT ALONG THE L SIDE OF THE ACFT, IT APPEARED TO ME THAT WE WERE CLRING THE TREES OFF THE APCH END OF THE RWY, BUT THAT WE WOULD NEED PWR TO MAKE THE RWY ITSELF. AT THAT POINT MY INSTRUCTOR ADVISED ME TO ADD PWR, WHICH I DID. ALMOST IMMEDIATELY THERE WAS A JOLT. WE APPARENTLY HIT THE UPPER BRANCHES OF A TREE THAT WAS BLOCKED BY THE NOSE TO MY LINE OF SIGHT. MY INSTRUCTOR TOOK CTL OF THE AIRPLANE AND LANDED WITHOUT FURTHER INCIDENT. THERE WERE NO INJURIES BUT THE AIRPLANE REQUIRES EXTENSIVE REPAIR. I WAS SO INTENT ON MAKING A NICE GLIDING TURN TO THE RWY, THAT I FORGOT THE AIRPLANE'S POOR VISIBILITY CHARACTERISTICS. MY ATTN SHOULD HAVE BEEN MORE EVENLY DIVIDED AMONG ALL OF THE FACTORS AFFECTING THE FLT.

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.