Small Aircraft
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Distraction; Communication Breakdown; Confusion; Situational Awareness; Time Pressure
Conflict NMAC
Flight Crew Took Evasive Action
Human Factors; Airspace Structure
On downwind in traffic pattern (stage check) at ZZZ; Instructor Pilot (IP) observed traffic on TIS (Traffic Information Service) display that appeared to be closing at a high rate from the rear. IP attempted to visually acquire the target; but was unable. ATC warned the following Aircraft Y that they were getting too close. While the IP's aircraft was cleared to land; Pilot under Instruction (PUI) decided to extend downwind to give sufficient space for traffic that was on final; and was not concerned with traffic to his rear since he had the right of way. With the targets continuing to close on the TIS; IP instructed PUI to turn immediately. As PUI turned base; IP acquired the target on downwind; passing an estimated 170 feet behind his aircraft; close enough to clearly read the registration Aircraft Y. IP continued flight without further incident. The instructor of Aircraft Y proceeded to solo out his student on the next lap.Keeping Situational Awareness (SA) is crucial to maintaining safety of flight; and using all available resources to maintaining SA. IP explained that it does not matter if you had the right of way if you crash; so do what is necessary per 91.3.
Flight instructor reported an NMAC with another instructional aircraft in the traffic pattern.