Da-40 instructor pilot reported being cut off by another aircraft while making a circle to land.

Attributes
ACN	1597620
Time
Date	201811
Local Time Of Day	1201-1800
Place
Locale Reference	AVQ.Airport
State Reference	AZ
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	DA40 Diamond Star
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	VFR
Aircraft 2
Make Model Name	Cessna Single Piston Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Person 1
Function	Pilot Not Flying Instructor
Qualification	Flight Crew Multiengine Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Commercial
Experience	Flight Crew Total 925
Events
Anomaly	Conflict Airborne Conflict Deviation - Procedural FAR Deviation - Procedural Published Material / Policy
Miss Distance	Horizontal 500 Vertical 50

Narrative:

I was on a VFR flight with a student and we were practicing an approach; RNAV GPS 12 at avq. We took airport advisories beforehand to see what runway they were using. They told us [runway] 30 was in use and from 14 miles out my student made calls with our position as well as our intentions of circling to land for 30. My student made various calls throughout the flight. Right before my student reached circling minimums; I [told] him to look up and to break off the approach to join right traffic for 30. My student did just this as I made the call to marana traffic. Shortly after; a cessna plane; swooped in right over us saying they were turning right crosswind for runway 30. My student said on the radios he had traffic in sight. I brought the power back and leveled out the plane to prevent any further climb/collision. The other plane was above us at traffic pattern altitude; about 3000 ft. They were above 500 ft. Above us and 50 ft. Ahead. We couldn't climb. And we could not turn nor slow the plane down; since we were already low on altitude. I told my student we would be doing a short approach since we definitely were low and we were at a good distance. I made the call on radios that we were turning base. Then; I also made the call that we were on final. The cessna pilot then realized we had gotten ahead. He said we had cut him off. But in actuality; 1) he had cut us off when we said we were breaking the approach to join downwind and 2) we were lower than him the whole time so lower aircraft have priority.

Original NASA ASRS Text

Title: DA-40 instructor pilot reported being cut off by another aircraft while making a circle to land.

Narrative: I was on a VFR flight with a student and we were practicing an approach; RNAV GPS 12 at AVQ. We took airport advisories beforehand to see what runway they were using. They told us [Runway] 30 was in use and from 14 miles out my student made calls with our position as well as our intentions of circling to land for 30. My student made various calls throughout the flight. Right before my student reached circling minimums; I [told] him to look up and to break off the approach to join right traffic for 30. My student did just this as I made the call to Marana traffic. Shortly after; a Cessna plane; swooped in right over us saying they were turning right crosswind for runway 30. My student said on the radios he had traffic in sight. I brought the power back and leveled out the plane to prevent any further climb/collision. The other plane was above us at traffic pattern altitude; about 3000 ft. They were above 500 ft. above us and 50 ft. ahead. We couldn't climb. And we could not turn nor slow the plane down; since we were already low on altitude. I told my student we would be doing a short approach since we definitely were low and we were at a good distance. I made the call on radios that we were turning base. Then; I also made the call that we were on final. The Cessna pilot then realized we had gotten ahead. He said we had cut him off. But in actuality; 1) he had cut us off when we said we were breaking the approach to join downwind and 2) we were lower than him the whole time so lower aircraft have priority.

Data retrieved from NASA's ASRS site 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.