Date: 201702
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Skylane 182/RG Turbo Skylane/RG
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Landing
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Second aircraft: Skyhawk 172/Cutlass 172
Reporter organization: Personal
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Human factors: Communication Breakdown
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Automation Aircraft TA; Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Human Factors; Airspace Structure
Primary problem: Airspace Structure

Narrative: Very nice sunny day. Lots of traffic in and around airport shooting approaches; training on pattern ops and landings; etc. Several planes had transmissions blocked due to multiple discussions/requests to/from tower. Tower instructed me to fly right downwind to Runway XY along with several other planes but also had airplanes on left downwind. While abeam numbers for XY I was instructed to do a left 360 for spacing. I completed my 360 and requested if I should circle again or could turn base or continue downwind. I was told I could turn base if I could identify the 2 planes on final for XY. My passenger confirmed with me we could see 2 planes so we were cleared #3 to land. The #2 plane was still pretty far out from runway; approx. 4 miles so we waited until he was on my 45 degree before turning base then final. Once established on final we re-identified the planes on final; seeing one landing; putting us in #2 position. Tower was talking to the 172 on left downwind and asked them to confirm the planes on final; they did; and I believe they cleared the 172 #3 or #4 to land (the instructor of the plane says he does not recall what position they were cleared for). At this point we were just coming up on the quarry at the end of Runway 5 - approx. 1.5 to 1 miles away. We saw the 172 clearly. They then proceeded to descend and turn inbound directly towards us. Our closure speed/distance/angle of descent appeared to us that it was going to result in a collision so I declared that I was aborting my final approach and making a right 360 to avoid the oncoming base traffic. The Tower has limited capability to see traffic and has no radar services. In a debrief with both the tower and the CFI the tower indicated they could not see our exact locations due to angle; etc and the CFI indicated he assumed the plane he saw on final as my plane. He admitted he failed to look far enough out for extended final traffic. He was very defensive. I believe a tower with no radar should not be clearing multiple planes to land unless both the tower and the airplanes can definitely identify the aircraft approved to land. I believe this was preventable had the CFI been paying more attention to the airport environment; which he eventually admitted to. Prior to the tower; all airplane operations would have been right downwind and we would not have been put in this situation. The tower should only clear a max of 2 planes at a time to land in situations where they have no radar and are unable to physically see the other planes they have cleared to land.




Synopsis: A Cessna 182 pilot reported that while on a long final approach he observed a Cessna 172 turning base directly toward him on a collision course.