Narrative:

While operating on a training flight into ues from the northwest; we were instructed to enter right downwind for runway 28. Once established on downwind; we were advised by waukesha tower that aircraft Y is on a 10 mile final for runway 28 into ues. We were also instructed by waukesha tower to extend our downwind to follow that traffic; and to advise when we had visual contact. We responded in compliance with the downwind extension instructions and that we were looking for the traffic. Shortly thereafter; about 1.5-2 NM east of the field; we made visual contact with the traffic; who was approximately 1 mile east/southeast of us and about 500 ft. Above us; descending towards runway 28 at ues. We contacted waukesha tower acknowledging visual contact with the traffic; and were instructed to maintain visual separation with the traffic; and follow it for landing. We responded in compliance with those instructions. As the traffic descended to approximately 100 ft. Above our altitude; they were approximately [at] our 2 o'clock position; well clear of being a factor. While observing the traffic; we witnessed it aggressively pitch up and initiate a missed approach. Aircraft Y then attempted to make a radio call; but a TCAS alert could be heard in the background. When prompted by waukesha tower to repeat the last transmission; aircraft Y's first officer responded that they were executing a missed approach due to a TCAS alert. The captain then followed up with a transmission regarding '150 ft.' of clearance indicated. As we continued our downwind; [the] tower contacted us to inquire about our position. We replied that we were continuing downwind and that aircraft Y was not a factor at any time. We were then instructed by waukesha tower to begin our base leg and then our clearance to land; to which we replied in compliance to the turn; and read back the landing clearance. The landing and subsequent taxi to parking were uneventful. After a brief discussion on the ground with the captain of aircraft Y following the event; he later informed me as to the berth requirements for their TCAS system onboard (I believe he stated ½ nm lateral separation; 500 ft. Vertical separation). Although the crew of aircraft Y did not report us in sight to [the] tower while in flight; the captain later stated that he saw the top of our wing as he initiated his missed approach; which corroborates with him being at a slightly higher altitude then us. However; we never began turning on a right base leg; as we had visual contact with aircraft Y and were maintaining visual separation with him throughout the sequence of events.

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Original NASA ASRS Text

Title: Instructor reported a NMAC with another plane in the landing pattern.

Narrative: While operating on a training flight into UES from the northwest; we were instructed to enter right downwind for Runway 28. Once established on downwind; we were advised by Waukesha Tower that Aircraft Y is on a 10 mile final for Runway 28 into UES. We were also instructed by Waukesha Tower to extend our downwind to follow that traffic; and to advise when we had visual contact. We responded in compliance with the downwind extension instructions and that we were looking for the traffic. Shortly thereafter; about 1.5-2 NM east of the field; we made visual contact with the traffic; who was approximately 1 mile east/southeast of us and about 500 ft. above us; descending towards Runway 28 at UES. We contacted Waukesha Tower acknowledging visual contact with the traffic; and were instructed to maintain visual separation with the traffic; and follow it for landing. We responded in compliance with those instructions. As the traffic descended to approximately 100 ft. above our altitude; they were approximately [at] our 2 o'clock position; well clear of being a factor. While observing the traffic; we witnessed it aggressively pitch up and initiate a missed approach. Aircraft Y then attempted to make a radio call; but a TCAS alert could be heard in the background. When prompted by Waukesha Tower to repeat the last transmission; Aircraft Y's First Officer responded that they were executing a missed approach due to a TCAS alert. The Captain then followed up with a transmission regarding '150 ft.' of clearance indicated. As we continued our downwind; [the] tower contacted us to inquire about our position. We replied that we were continuing downwind and that Aircraft Y was not a factor at any time. We were then instructed by Waukesha Tower to begin our base leg and then our clearance to land; to which we replied in compliance to the turn; and read back the landing clearance. The landing and subsequent taxi to parking were uneventful. After a brief discussion on the ground with the Captain of Aircraft Y following the event; he later informed me as to the berth requirements for their TCAS system onboard (I believe he stated ½ nm lateral separation; 500 ft. vertical separation). Although the crew of Aircraft Y did not report us in sight to [the] tower while in flight; the Captain later stated that he saw the top of our wing as he initiated his missed approach; which corroborates with him being at a slightly higher altitude then us. However; we never began turning on a right base leg; as we had visual contact with Aircraft Y and were maintaining visual separation with him throughout the sequence of events.

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.