Small Aircraft
Flight Crew Instrument
Flight Crew Last 90 Days 50; Flight Crew Total 1460; Flight Crew Type 850
Situational Awareness; Communication Breakdown; Confusion
Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Took Evasive Action
Procedure; Human Factors
While doing closed circuit touch-and-go's at KGIF Winter Haven; FL I was sharing the pattern with a [another aircraft] (Aircraft Y). We were communicating on the CTAF and alternating without conflict or difficulty. As I took off from Runway 29 I saw what appeared to be [the other aircraft (Aircraft Z)] at my 12:00 and less than 500 feet ahead and above. I [was aware] that aircraft X that I was communicating with was turning base to final; so could not understand how he had gotten ahead and directly above me. I called that I had the aircraft in sight directly ahead and above. Aircraft then made a tight right turn away from the left-hand pattern for Runway 29. Aircraft Y that I was communicating with called short final; so there were now two aircraft at KGIF; one not communicating and interfering with the flow of traffic. I turned left and called crosswind; then downwind while communicating with Aircraft X who was taking off and turned crosswind behind me when I was abeam the numbers. I called base and final for a simulated engine-out touch-and-go. When turning base to final Aircraft Z turned directly in front of me; approximately 300 feet below; from a non-standard right-hand pattern. I called a go-around and overflew the aircraft; which was no longer seen when I turned crosswind. I continued to be in communication with Aircraft X; who landed after that circuit. Aircraft Z was flying without radio communication and flying a non-standard pattern in the face of active pattern work by two other aircraft.
A general aviation pilot reported a near-mid-air-collision with an aircraft at a non-towered airport that was not using a radio and was flying a non-standard pattern.