Date: 202107
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 30
Light: Daylight
Aircraft: Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Initial Approach; Final Approach
Airspace: Class G ZZZ
ATC / advisory: CTAF ZZZ
Second aircraft: Small Aircraft; High Wing; 1 Eng; Fixed Gear
Reporter organization: Personal
Reporter function: Single Pilot
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor
Human factors: Communication Breakdown
Anomaly: Conflict NMAC
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: While on right downwind at Traffic Pattern Altitude (1000 MSL) to land runway XX at ZZZ; I reduced power abeam the arrival end of runway XX and started my descent. I was momentarily looking at the airport runway as I reduced my power. I then returned my vision to straight ahead and spotted a high wing airplane towing a banner approximately 100 feet below me; coming directly at me from my 11-12 o'clock position. He was less than 1/4 mile away when I first spotted him. At that time my altitude was approximately 950 feet. I immediately added power and pulled up as he passed no more than 100 feet below me and no more than 100 feet to my left. After he passed under me; he turned out to the west and departed the area at the same altitude. I made a radio call to the aircraft telling him he nearly hit me but he did not respond. Prior to that time; I had made 5 radio calls announcing my position and intentions beginning 8 miles north of the airport.The banner tow plane flew right through the ZZZ traffic pattern; directly opposing downwind traffic on the right downwind and between 100 and 150 ft. of traffic pattern altitude. He should not have been flying through the traffic pattern and was not communicating with aircraft in the area on the CTAF. He was initially in my forward blind spot; just under my nose. I spotted him when I lowered my nose to start my descent for landing on the downwind leg. He was a high wing aircraft (fabric body; silver colored) and likely did not see me above and slightly to his left. The approaching banner tow aircraft was not spotted until he was less than 1/4 miles ahead. Contributing factors were:1. His position in my forward blind spot below the aircraft nose. 2. A second factor is that the banner towing aircraft was approaching head on and provided a small profile for both the aircraft and the banner.3. He was flying through an active traffic pattern with aircraft actively communicating on the CTAF.4. He was not communicating his position or intentions on the CTAF while operating in the airport traffic pattern5. He was flying a non-standard traffic pattern leg; i.e.; opposed to downwind traffic.6. He was approaching from a position that was at first spotting; slightly outside the traffic pattern. Aircraft in the traffic pattern are dividing attention between the traffic pattern and the runway environment. My attention was diverted toward the runway for a few seconds just prior to the time the aircraft was first spotted.7. The banner towing pilot has a dangerous habit of flying through the traffic pattern at this airport as described in the additional incident below which occurred earlier on the same day. Additional Relevant Information:Earlier that day another pilot had a near miss with the same aircraft at the same location. He also had to take evasive action to avoid the aircraft. In his case; he was on right base for runway XX and the banner towing aircraft was just above his altitude.




Synopsis: Instructor reported an NMAC with a banner towing aircraft in the traffic pattern.