Narrative:

We were on a right downwind for the runway. I was with my student going over tower operations when I thought I heard him say that we were landing behind the cessna [that was] behind the citation so I thought that we were number 2 when really we were number 3 for landing. I turned base on top of an airplane that was below us and he saw and made an evasive action and went missed while I slowed down because he was coming close to us. I got distracted giving my student instruction when I should have been paying more attention to the clearance. Both of our airplanes came close but not too close to where I had to make a quick evasive action. It wasn't until I was on final that the airplane below us realized what was going on and he went around.

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Original NASA ASRS Text

Title: C172 instructor pilot experiences confusion when instructed by the Tower to follow a Cessna which is following a Citation. Believing he is number two; the early base turn results in a NMAC with the preceding Cessna and results in that Cessna going around.

Narrative: We were on a right downwind for the runway. I was with my student going over tower operations when I thought I heard him say that we were landing behind the Cessna [that was] behind the Citation so I thought that we were number 2 when really we were number 3 for landing. I turned base on top of an airplane that was below us and he saw and made an evasive action and went missed while I slowed down because he was coming close to us. I got distracted giving my student instruction when I should have been paying more attention to the clearance. Both of our airplanes came close but not too close to where I had to make a quick evasive action. It wasn't until I was on final that the airplane below us realized what was going on and he went around.

Data retrieved from NASA's ASRS site as of April 2012 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.