Flight Crew Commercial; Flight Crew Flight Instructor
Flight Crew Last 90 Days 175; Flight Crew Total 400; Flight Crew Type 330
Communication Breakdown; Situational Awareness
Conflict NMAC; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Took Evasive Action
Human Factors
While practicing ground reference maneuvers with my pre-solo private pilot student; I noticed a plane flying on a course that would intercept our maneuvering area. My ADSB-in noticed the plane and soon after I had visual contact. I made announcements of my position on the local CTAF that is used in that area; due to the proximity of the airport that the flight training is conducted out of. No response was made by the incoming aircraft. Due to my position I took controls from my student and altered our course to the right in an attempt to clear the area. Aircraft Y flew towards me as indicated by my ADSB equipment; as well as the small amount of visual contact I had as the aircraft moved to a chasing position. Slow controlled turns were made to try to get the aircrafts attention (I did not know if Aircraft Y had me in visual contact) as well as vacate the area due to this aircraft. The collision avoidance sounded multiple times that Aircraft Y was on a direct collision course with me; and indicating on my screen that we had less than 100 ft. of vertical and horizontal clearance. In the closest proximity I was unable to maintain visual contact due to the other aircraft being behind me; and slightly above me. This continued on for a period of somewhere between 3-5 minutes. No matter the direction I flew to try and vacate the area Aircraft Y stayed on my tail. All attempts to establish radio contact failed. The traffic eventually vacated the area to the south of our position.Looking back I should have called St. Louis Approach and let them know of the situation; giving them the opportunity to try to establish radio contact and let the pilot of Aircraft Y know we were a training flight that was not comfortable flying in formation as well as let ATC know that this aircraft was breaking the law and creating a dangerous situation for themselves as well as others.
C172 pilot reported an NMAC with another light aircraft.