C172 Flight Instructor reported a NMAC event during downwind entry pattern with downwind traffic. The downwind traffic aircraft proceeded to do a 360 turn in the downwind leg to give extra spacing and both airplanes landed without further incident.

ACN 2053684 2023-11 Skyhawk 172/Cutlass 172 General Aviation Flight Training Reports

Initial ApproachPart 91

What is ASRS?

The Aviation Safety Reporting System is NASA's voluntary, confidential, non- punitive incident-reporting system, established 1976. Pilots, controllers, dispatchers, and maintenance technicians file reports describing safety- relevant events. NASA de-identifies every report before adding it to the public database. Reports are not investigated by NASA, the FAA, or the NTSB — they represent the reporter's perspective.

Pilot narrative

Verbatim from the de-identified NASA record. First-person account by the reporter. NASA strips identifying details (names, company, specific time); anonymization placeholders are ZZZ, X, Y.

C172 was entering traffic pattern for Runway XX at ZZZ with standard 45 degree midfield left downwind entry for Runway XX at pattern altitude of 1,350 [ft.] MSL. On board the airplane was 1 student pilot and 1 flight instructor. Traffic calls were made at 5 miles out on the 45 for left downwind. Aircraft Y was in the pattern on a crosswind leg and turned downwind as C172 entered downwind. Occupants on the C172 never saw Aircraft Y and never heard crosswind traffic call however Aircraft Y pilot stated on CTAF he was at 1,600 ft. MSL instead of traffic pattern altitude and stated if he were at correct traffic pattern altitude the aircraft would have been very close to collision. Estimated separation approximately 400 ft. Aircraft Y proceeded to do a 360 turn in the downwind leg to give extra spacing and both airplanes landed without further incident.

NASA classification — Anomalies

Conflict
Deviation - Altitude
Deviation / Discrepancy - Procedural

NASA classification — Assessments

Contributing Factors / Situations: Human Factors
Primary Problem: Human Factors

ASRS reports are voluntarily submitted, de-identified by NASA, and represent the reporter's perspective. The presence of reports on a topic cannot be used to infer prevalence in the National Airspace System. The authoritative source is the NASA ASRS Database Online at asrs.arc.nasa.gov ↗.