Narrative:

During an instrument training flight my student and myself approached byron airport from the north, with the intention of practicing some takeoffs and lndgs. My student had his view limiting device removed 5 mi from the airport. We made radio reports at the following points, 5 mi right 45 degrees, 2 mi right 45 degrees, right downwind, right base, final runway 30. On short final for runway 30 I saw an aircraft on a low, close-in downwind for runway 30. On short final the other aircraft turned his base which put us on a collision course. I initiated a go around. A second or two later, the other aircraft made a steep left turn. I then lost sight of him. Neither myself, my student or the piper arrow on downwind behind us heard any radio calls from the ultralight aircraft. Several mins later as we approached right base runway 30, I noticed the ultralight on a northerly heading about 1/4 mi east of our position. After we landed we heard some weak, scratchy calls from the ultralight pilot as he entered the pattern again. He then proceeded to land and taxied to the hangar area. My student and I flew around the pattern a few more times then departed VFR to rhv.

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Original NASA ASRS Text

Title: NMAC BTWN A C172 AND AN ULTRALIGHT AT A NON TWR ARPT. ULTRA WAS LOW AND CLOSE-IN ON DOWNWIND LEG OF TFC PATTERN AND TURNED INTO C172 ON FINAL. NO RADIO CALLS FROM ULTRALIGHT.

Narrative: DURING AN INST TRAINING FLT MY STUDENT AND MYSELF APCHED BYRON ARPT FROM THE N, WITH THE INTENTION OF PRACTICING SOME TKOFS AND LNDGS. MY STUDENT HAD HIS VIEW LIMITING DEVICE REMOVED 5 MI FROM THE ARPT. WE MADE RADIO RPTS AT THE FOLLOWING POINTS, 5 MI R 45 DEGS, 2 MI R 45 DEGS, R DOWNWIND, R BASE, FINAL RWY 30. ON SHORT FINAL FOR RWY 30 I SAW AN ACFT ON A LOW, CLOSE-IN DOWNWIND FOR RWY 30. ON SHORT FINAL THE OTHER ACFT TURNED HIS BASE WHICH PUT US ON A COLLISION COURSE. I INITIATED A GAR. A SECOND OR TWO LATER, THE OTHER ACFT MADE A STEEP L TURN. I THEN LOST SIGHT OF HIM. NEITHER MYSELF, MY STUDENT OR THE PIPER ARROW ON DOWNWIND BEHIND US HEARD ANY RADIO CALLS FROM THE ULTRALIGHT ACFT. SEVERAL MINS LATER AS WE APCHED R BASE RWY 30, I NOTICED THE ULTRALIGHT ON A NORTHERLY HEADING ABOUT 1/4 MI E OF OUR POS. AFTER WE LANDED WE HEARD SOME WEAK, SCRATCHY CALLS FROM THE ULTRALIGHT PLT AS HE ENTERED THE PATTERN AGAIN. HE THEN PROCEEDED TO LAND AND TAXIED TO THE HANGAR AREA. MY STUDENT AND I FLEW AROUND THE PATTERN A FEW MORE TIMES THEN DEPARTED VFR TO RHV.

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.