Small Aircraft; High Wing; 1 Eng; Fixed Gear
Flight Crew Private
Flight Crew Last 90 Days 14; Flight Crew Total 80; Flight Crew Type 80
Communication Breakdown; Situational Awareness
Conflict NMAC; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors
I was conducting a training flight and was headed to N40. Approximately 4 miles south of the airport; I made a radio call on UNICOM announcing I was 4 miles south at 2;000 feet descending to pattern with intentions to join the left downwind Runway 25 using a standard 45 degree entry. As I continued to approach the airport; I was scanning in front; to the left; and to the right of me while listening to the radio for relevant traffic. When I was about to make my entry to join a left downwind; I made a radio call announcing that I was joining the downwind leg of Runway 25. Prior to turning; I made a quick scan to the left; center; and right. I did not see any traffic. As I started my turn; I scanned left again and saw a Piper on downwind approximately 200 feet horizontally to the left of my aircraft and 60 feet vertically beneath me. Simultaneously; I heard the Piper make a radio call announcing they were breaking off the downwind and saw the Piper turn away from my aircraft. I judged that the situation was under control so I continued my turn to join downwind and made a radio call to the Piper stating that I had him in sight and apologized for cutting him off in the pattern. The rest of the flight was uneventful. Contributing factors include: 1; Either a lack of an initial radio call from the Piper; or myself missing the radio call from the Piper. 2; I had made a radio call that I was making a 45 degree entry to join the left downwind; but mispositioned my aircraft and made a turn closer to 90 degrees instead. This positioning error may have led the Piper to scan the wrong area. 3; Too fast a scan to detect an aircraft against the backdrop of the ground 4; Busy UNICOM frequency with a lot of radio calls from multiple airports. Regarding human performance considerations; I made a poor judgment to continue to approach the airport directly from the south rather than change course to put the aircraft into a better position for a 45 degree entry to downwind. Additionally; as I was not aware of any radio calls for an aircraft in the pattern at N40; I should have conducted a more thorough scan to look for unexpected aircraft. While I was scanning in all directions; I moved from one sector to another relatively quickly which likely caused me to miss the Piper and reinforce my perception that there were no other aircraft in the pattern. To prevent a recurrence of the situation; I will start thinking about my initial approach direction to an airport further out than I currently do. This should help ensure proper positioning for entry into the pattern and help other traffic locate me. I will also improve my scan and spend more time on each sector. This should greatly improve my ability to spot any unexpected aircraft.
Pilot reported an NMAC event while entering traffic pattern.