An instructor pilot reported a near midair collision on short final.

Attributes
ACN	1742777
Time
Date	202005
Local Time Of Day	1201-1800
Place
Locale Reference	TTD.Tower
State Reference	OR
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Route In Use	None
Flight Plan	None
Aircraft 2
Make Model Name	Small Aircraft High Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Flight Plan	None
Person 1
Function	Pilot Not Flying
Qualification	Flight Crew Flight Instructor Flight Crew Commercial Flight Crew Instrument
Experience	Flight Crew Last 90 Days 79 Flight Crew Total 384 Flight Crew Type 238
Events
Anomaly	ATC Issue All Types Conflict NMAC
Miss Distance	Horizontal 200 Vertical 100

Narrative:

I was serving as a certified flight instructor conducting part 61 flight training with a student pilot. My student pilot was in control of the aircraft. We were on the downwind for runway 25. We were told to extend downwind. Soon after was cleared to land runway 25. We were on an extended final and number 1 for landing. While on final I saw an aircraft on the downwind off my 10 o clock position begin to turn base for runway 25 and descent rapidly toward us. The other aircraft was descending directly in front of and on top of us on a collision course. ATC was unclear which aircraft was which and therefore unable to provide conflict resolution instructions. I took control of the aircraft and took evasive action; diving under the aircraft and in the opposite direction. We were headed toward a hillside and once I felt that the aircraft was behind us; I climbed at the highest rate possible to get over and beyond the hillside. The other aircraft continued to land. We were circled around the then landed without further incident.

Original NASA ASRS Text

Title: An instructor Pilot reported a NMAC on short final.

Narrative: I was serving as a certified flight instructor conducting part 61 flight training with a student pilot. My student pilot was in control of the aircraft. We were on the downwind for Runway 25. We were told to extend downwind. Soon after was cleared to land Runway 25. We were on an extended final and number 1 for landing. While on final I saw an aircraft on the downwind off my 10 o clock position begin to turn base for Runway 25 and descent rapidly toward us. The other aircraft was descending directly in front of and on top of us on a collision course. ATC was unclear which aircraft was which and therefore unable to provide conflict resolution instructions. I took control of the aircraft and took evasive action; diving under the aircraft and in the opposite direction. We were headed toward a hillside and once I felt that the aircraft was behind us; I climbed at the highest rate possible to get over and beyond the hillside. The other aircraft continued to land. We were circled around the then landed without further incident.

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.