Date: 201511
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Cessna Single Piston Undifferentiated or Other Model
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Final Approach
Airspace: Class G ZZZ
ATC / advisory: CTAF ZZZ
Second aircraft: Small Aircraft
Reporter organization: Personal
Reporter function: Single Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Situational Awareness
Anomaly: Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Executed Go Around / Missed Approach; Flight Crew Took Evasive Action
Contributing factors: Human Factors; Airport
Primary problem: Human Factors

Narrative: Intending to practice wheel landings on the grass runway; I entered left traffic to Runway XXL. The CTAF frequency was somewhat busy; with 3 helicopters practicing on the north part of the field; and 2 or 3 fixed-wing aircraft in the pattern for Runway YY. Winds were 050 at 10+ knots and I was surprised to find traffic on 31. It was light enough that I thought I could work in some Runway XXL patterns; so I continued on the downwind. From the downwind; I noticed 2 mowers on the west part of Runway XXL and began to plan for the possibility they would not vacate the rwy.Just after I called my base turn; with the addition of 'stop & go' to account for a brief stop (10 seconds or less) before my planned continuation; an aircraft called that he was taking Runway YY for departure. I intended to make a CTAF call to ensure deconfliction; but just then a long discussion between two helicopters ate up all the radio time. At this point I was dividing my attention between the approach end of Runway YY and the mowers on Runway XXL. I was unable to confidently determine the position and actions of the departing Runway YY traffic and assumed the worst; that a conflict was developing.One mower vacated; but the intentions of the other were unclear. I prepared for a possible go-around and tried to pick up the Runway YY traffic. On short final; uncertain of the intentions of the remaining mower and uncertain whether I could stop short of the Runway XXL-YY intersection should the need arise; I began a go-around. A helicopter made an alarmed call to the effect that 'there are two of you taking off' at which point I picked up the Runway YY departure at my right 2-o'clock for 2000 feet at about 100 ft AGL on climb out. I transmitted that I would stay low and leveled off at 20-30ft AGL. I maintained the visual and ensured separation as I flew more or less directly underneath the departing aircraft. My best guess is that he was at 200-300 ft AGL when our paths crossed.In hindsight; with a busy frequency and intersecting runways; the presence of the mowers made my pattern to Runway XXL unadvisable; since it had the potential to reduce my options. I could have waited for a break in the traffic or come back another day. I also wonder if my stop & go call caused the Runway YY departure to assume I was LAHSO. I was hoping to clear this up on 1 mile final when the radio congestion made it impossible. My go-around decision was also late. I could have discontinued the approach much earlier and altered my flight path to eliminate the potential for a close pass.




Synopsis: Cessna pilot attempting to use an intersecting grass runway to practice wheel landings discovers mowers on the runway and other fixed wing traffic using the paved intersecting runway. On short final with one mower still on the runway and unseen traffic departing on the intersecting runway; the reporter elected to go around resulting in a NMAC as he flies under the departing traffic.