GA flight crew on arrival and a GA pilot on departure reported a NMAC with each other requirng evasive action to avoid a collision. ATC failed to advise either aircraft of conflicting traffic.
Synopsis
GA flight crew on arrival and a GA pilot on departure reported a NMAC with each other requirng evasive action to avoid a collision. ATC failed to advise either aircraft of conflicting traffic.
Narrative
I was sitting in the left seat; acting as PIC of my father's aircraft; Aircraft X. I was flying the Fisk arrival to Runway 27 with my father; a commercial pilot-qualified passenger in the right seat. We were directly over the train tracks at 1800 ft MSL; indicating 130 kts; crossing about 1.2nm from the departure end of Runway 27; as prescribed by the arrival procedure. We were monitoring 118.50 as instructed by the Fisk arrival controller for the approach to Runway 27 at OSH. I was looking outside to the left momentarily in order to align us inside the gravel pit for the coming transition to the Runway 27 downwind leg. I heard my father yell 'aircraft!' and turned my head to the right side section of our wind screen. I saw Aircraft Y in very close proximity seeming to fill the entire windscreen as it closed in rapidly; head-on. As I registered the imminent collision; my father had already pushed the flight controls forward to initiate a dive away from the conflict. As I processed the surreal scene of sure collision in which I could see the pilot sitting in the left seat of the aircraft through his windscreen; I joined my father on the controls pushing with him; down and to the right while I reduced power to prevent airframe over-stress as our dive approached nearly vertical. The aircraft simultaneously passed no more than 10feet above us. The dive dislodged so many objects and tools stored in the cabin which when flying wildly about the cabin created the illusion of debris from an impact to the aircraft's structure. I rapidly focused attention to pulling out of the dive and noticed normal handling characteristics; realizing we had avoided collision. Returning to level flight; I reestablished the aircraft on the arrival path as my dad contacted the approach controller on 118.5 to inform him that we had nearly been hit by a departing aircraft. We continued the approach and landed without further incident.
Second reporter narrative
My aircraft X being piloted by my son was on the Fisk arrival to Runway 27. My son was PIC in the left seat; and I was a pilot qualified passenger in the right seat. We were directly over the tracks (62 degrees magnetic) at 1800 ft. MSL; 130 kts crossing about 1.2 NM from the departure end of Runway 27. Exactly as required by the arrival notice. We were monitoring 118.50 as instructed by the Fisk arrival controller for the approach to Runway 27 at OSH. I looked up from the instruments out the windscreen; forward to the right in the direction of the runway to see Aircraft Y climbing directly toward us. (Later learned [it was] Aircraft Y.) Clearly climbing directly at us at close proximity; I yelled 'aircraft' and with open palms pushed the yoke in front of me forward to dive the aircraft below the path of the other aircraft. I was unsure if the noise in the cockpit was the other aircraft striking us; or just our heads and the contents of the cabin striking the ceiling. I estimate that the push I made on the controls allowed us to pass no more than 10 ft. below Aircraft Y. Immediately following the push; my son regained control of the aircraft and recovered from the dive and re-established us on the arrival path. Upon entering the downwind I called the approach controller on 118.5 and told him that we almost got hit by an aircraft on departure. We continued the approach and landed without further incident.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.