Narrative:

We were conducting pattern work on a taxiway parallel to the runway in use (runway 4R). This was probably our 8TH pattern; right traffic. We were setting up for an autorotation and maintained an altitude of 500 ft AGL all the way to final. As we were finishing our turn from base to final; the pitts passed right in front of us on a steep descending turn. We were both in right traffic; he passed right to left. The pitts had not been conducting pattern work; I believe they had transitioned in from the south for landing. Upon seeing the aircraft; I took controls from my student and continued a hard right turn to pass behind. Once clear; we realigned ourselves with the taxiway. We notified the tower that a biplane had passed across our flight path on final. The tower acknowledged that they heard us; but did not make any further statement. As the instructor; I was in the left seat. With right hand turns; this made it difficult to see traffic to the right and nearly impossible to see to the right and above. Both aircraft were cleared to land. Normal patterns should have kept us separated; however; the biplanes have a history of cutting inside the standard helicopter pattern at this airport.

Google
 

Original NASA ASRS Text

Title: HELI IN PATTERN AT CHD; PRACTICING AUTO ROTATION TO TXWY; EXPERIENCED NMAC WITH ACFT ON SHORT APCH TO PARALLEL RWY.

Narrative: WE WERE CONDUCTING PATTERN WORK ON A TXWY PARALLEL TO THE RWY IN USE (RWY 4R). THIS WAS PROBABLY OUR 8TH PATTERN; R TFC. WE WERE SETTING UP FOR AN AUTOROTATION AND MAINTAINED AN ALT OF 500 FT AGL ALL THE WAY TO FINAL. AS WE WERE FINISHING OUR TURN FROM BASE TO FINAL; THE PITTS PASSED RIGHT IN FRONT OF US ON A STEEP DSNDING TURN. WE WERE BOTH IN R TFC; HE PASSED R TO L. THE PITTS HAD NOT BEEN CONDUCTING PATTERN WORK; I BELIEVE THEY HAD TRANSITIONED IN FROM THE S FOR LNDG. UPON SEEING THE ACFT; I TOOK CTLS FROM MY STUDENT AND CONTINUED A HARD R TURN TO PASS BEHIND. ONCE CLR; WE REALIGNED OURSELVES WITH THE TXWY. WE NOTIFIED THE TWR THAT A BIPLANE HAD PASSED ACROSS OUR FLT PATH ON FINAL. THE TWR ACKNOWLEDGED THAT THEY HEARD US; BUT DID NOT MAKE ANY FURTHER STATEMENT. AS THE INSTRUCTOR; I WAS IN THE L SEAT. WITH R HAND TURNS; THIS MADE IT DIFFICULT TO SEE TFC TO THE R AND NEARLY IMPOSSIBLE TO SEE TO THE R AND ABOVE. BOTH ACFT WERE CLRED TO LAND. NORMAL PATTERNS SHOULD HAVE KEPT US SEPARATED; HOWEVER; THE BIPLANES HAVE A HISTORY OF CUTTING INSIDE THE STANDARD HELI PATTERN AT THIS ARPT.

Data retrieved from NASA's ASRS site as of May 2009 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.