Date: 202107
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Skyhawk 172/Cutlass 172
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Initial Approach
Airspace: Class E ZZZ
ATC / advisory: CTAF ZZZ
Second aircraft: PA-25 Pawnee
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown
Anomaly: Conflict NMAC; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure
Primary problem: Procedure

Narrative: I was approach the ZZZ from the north; preparing to perform a touch and go at the airport before flying northbound back towards ZZZ1. Before beginning my VFR descent; I obtained the current weather at the airport; and I found that the wind would be favoring Runway XX at the airport. From there I determined that in order to conduct a standard pattern entry; I should overfly the airport at 1;700 ft. MSL or 500 ft. above pattern altitude; and then perform a 225 degree turn to enter the left downwind from a 45 degree angle to Runway XX. At 10 miles; I began to announce my intentions regularly at intervals of approximately 2.5 miles.At a distance of around 5 miles from the airport; a Piper Pawnee preparing to tow a glider announced that they would be making a right downwind departure from Runway XX; towards the east. This would be the only transmission I noted from this aircraft until I would be touching down on Runway XX. I continued approaching the airfield and I had the two aircraft in sight. As the Pawnee turned downwind; I noted that my flight path would create a collision hazard; should I have continued my descent. As such; I immediately applied full power and climbed to 2;800 ft. MSL. I continued to watch as the Pawnee; with its glider in tow passed underneath me by approximately 500 ft. Climbing was likely the best evasive action in this case because I was in a high wing Cessna; while he was in a low-wing Pawnee. Had I descended; we both would have lost visual contact with each other and no additional action could have been taken should it have been necessary. The factors which appear to have contributed to this event appear to be the Pawnee pilot's lack of communication when departing; thus preventing me from restructuring my arrival plan so that I may safely avoid him. Additionally; he utilized a non-standard right downwind departure that was not charted at the airport for Runway XX. I believe that the Pawnee pilot could have extended their crosswind leg so as to remain well clear of me. On my own part; I should have taken earlier action to increase separation such as maintaining 3;000 ft. over the airport; as I was indeed aware that he would be making right traffic and climbing out of the airport. I had misjudged the climb rate of the Pawnee; and as such suspected that I could pass in front and above them before there would have been a collision hazard.




Synopsis: Pilot reported taking evasive action to avoid a mid air collision with a glider tug that made a non-standard departure.