Small Aircraft; High Wing; 1 Eng; Fixed Gear
Air Traffic Control Developmental
Situational Awareness; Distraction; Communication Breakdown; Confusion; Training / Qualification
ATC Issue All Types; Conflict NMAC; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
ATC Equipment / Nav Facility / Buildings; Human Factors; Procedure
Aircraft X was in the right downwind for Runway 22 and Aircraft Y was final for the LDA/DME Runway 22 Approach. I told Aircraft X to make left 360's in the downwind until advised. Aircraft X complied but ended up crossing Runway 22 final and came in proximity to Aircraft Y. Aircraft Y reported that the Aircraft X came close to him. After Aircraft Y was over the threshold then Aircraft X reported Aircraft Y in site. Another contributing factor was the ASR-11 was under maintenance during busy traffic and it was hard to judge the speeds of the aircraft on final when they were too far away to see. I should have been clear to Aircraft X to remain north of Runway 22 final for landing traffic. Also that the ASR-11 shouldn't be taken when we have numerous traffic in our airspace.
The radar was inoperative at AMA when the occurrence took place. There were multiple military trainers in the pattern performing touch and goes along with a beech jet and the Aircraft I was flying with my instructor. The Tower Controller was very busy keeping everyone separated and during this particular traffic pattern flight during my downwind leg he had me perform a left 360 degree turn and continue downwind which I complied with. Once coming out of the first 360 and continuing briefly on my downwind leg he requested another 360 degree turn and then a third before extending downwind. At this point I was past the end of the numbers and he had me go into a fourth 360. I continued downwind following that 360 degree turn before seeing below me and to my left Aircraft Y fly past on final approach. My instructor and I caught it out of our peripheral vision about the same time and he responded to the controller that Aircraft Y had passed just under us. By the time we saw Aircraft Y it was already past us. We then took a turn away from the pattern to the north and communicated back and forth with ATC who asked us to proceed to a heading of 270 before having us turn right base for Runway 22. I believe there were a number of issues that caused this problem. One was the communication between ATC and myself as he was very busy and may have forgot that I had completed my 360 and was continuing downwind. He later mentioned that he had requested I stay in a 360 degree turn after turn until further direction but I never heard that statement nor believe it was said. The aircraft I was flying; a [type removed]; makes a 360 degree turn rather quickly and is rather slow and the other aircraft that were up that morning were obviously much faster so timing and spacing us out was probably difficult for ATC especially with the radar being down. The fact that Aircraft Y was essentially directly in front of me approaching below my altitude caused me to not have a clear sight of his approach as my vision was blocked by the engine cowling in front. My multiple 360 degree turns may also have moved my downwind leg closer to the runway than further from it although I can't say as a fact as the runway was behind me at this point and I was not looking behind me. The sun was high enough and to my right that I do not believe the sun impaired my vision.
AMA controller and pilot of one of the aircraft involved report of a near miss due to the aircraft on downwind coming in close proximity of the trainer jet on a straight in final.  Pilot was told to make 360's on downwind; but flew close to the final.