This is an excerpt from a report made to the Aviation Safety Reporting System. The narrative is written by the pilot, rather than FAA or NTSB officials. To maintain anonymity, many details, such as aircraft model or airport, are often scrubbed from the reports.
Busy airport traffic pattern on my lesson solo. Multiple aircraft in traffic pattern of several different types.
I was instructed to make left base for Runway 30L. I started to turn base without being cleared to land.
Two aircraft, including myself and another aircraft which was on a very extended downwind south of the delta nearly 5 miles south of where I was turning base, were instructed to make a right turn to re-enter the downwind to give landing space to an air carrier.
I had never heard this command but interpreted it to mean to make a 360 back into the traffic pattern.
Aircraft Y in front of me was given the instruction first and immediately started their turn to the right. When I was given the instruction, I waited to try to ask Gateway Tower what they meant, but the frequency was too busy.
I decided to start the turn to the right to make a 360 to re-enter the downwind. Unfortunately, my slow thinking led to me making a turn at the same time that the aircraft in front of me was already almost finished with their turn. This resulted in a near head-on collision.
The other aircraft fortunately realized this, pulled up, and turned to their right promptly. I saw the aircraft fly over me and assumed it was an aircraft coming south from the gap with an odd pattern entry.
Although a bit flustered, I was able to land the airplane and thought of it as a bad coincidence. The flight instructor on-board the other aircraft in the incident approached me after my flight and asked to discuss once I returned. We discussed the incident and my flight instructor who was not on-board my solo flight was also notified and joined us in the debrief.
Primary Problem: Human Factors