C172 instructor pilot on downwind at prc reports a near midair collision with another C172 entering ...

Narrative:

We were extended for almost 5 miles upwind before being cleared to turn our crosswind. While still far out on the downwind; tower cleared another aircraft not even in the pattern yet to land and follow another aircraft on final. The aircraft replied they were still looking for traffic. I kept monitoring my student's downwind. About midfield downwind while watching my student's airspeed and altitude; a target popped up on our ads-B mfd display just in time for me to look up and see this aircraft diving down from above and behind us on the left into the downwind right in front of us. I immediately took the controls from my student and initiated a 360 turn in the downwind and informed tower what we were doing. Tower replied and apologized and soon after I noticed another controller took over. I believe the incident occurred because the previous controller was not monitoring traffic flow and sequencing correctly and the fact that this other aircraft had an inoperative transponder as do several other aircraft from this FBO. Being a highly congested airspace; having a transponder would have allowed us to see the aircraft earlier and possibly slow down or maneuver appropriately for spacing. Tower needs to address issues with sequencing and flow as there has been an increase in these problems recently.

Original NASA ASRS Text

Title: C172 instructor pilot on downwind at PRC reports a NMAC with another C172 entering the pattern under Tower control. Reporter informs the Tower and initiates a right 360 to reenter the downwind.

Narrative: We were extended for almost 5 miles upwind before being cleared to turn our crosswind. While still far out on the downwind; Tower cleared another aircraft not even in the pattern yet to land and follow another aircraft on final. The aircraft replied they were still looking for traffic. I kept monitoring my student's downwind. About midfield downwind while watching my student's airspeed and altitude; a target popped up on our ADS-B MFD display just in time for me to look up and see this aircraft diving down from above and behind us on the left into the downwind right in front of us. I immediately took the controls from my student and initiated a 360 turn in the downwind and informed Tower what we were doing. Tower replied and apologized and soon after I noticed another Controller took over. I believe the incident occurred because the previous Controller was not monitoring traffic flow and sequencing correctly and the fact that this other aircraft had an inoperative transponder as do several other aircraft from this FBO. Being a highly congested airspace; having a transponder would have allowed us to see the aircraft earlier and possibly slow down or maneuver appropriately for spacing. Tower needs to address issues with sequencing and flow as there has been an increase in these problems recently.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1078329
Time
Date	201304
Local Time Of Day	0601-1200
Place
Locale Reference	PRC.Airport
State Reference	AZ
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Descent
Flight Plan	None
Aircraft 2
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Descent
Person 1
Function	Instructor Pilot Not Flying
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Commercial
Experience	Flight Crew Last 90 Days 40 Flight Crew Total 700 Flight Crew Type 500
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 300 Vertical 0

C172 instructor pilot on downwind at prc reports a near midair collision with another C172 entering the pattern under tower control. Reporter informs the tower and initiates a right 360 to reenter the downwind.