Narrative:

Performing a biennial flight review; we were performing pattern work to a touch and go. On mid field downwind; aircraft Y announced (exact verbiage): 'aircraft Y; midfield left downwind for a right 45 degree; runway 09' (I don't even know what that means?) as I was also midfield downwind; I became very concerned. I requested DME to field from aircraft Y; but he responded; 'midfield downwind'. Again; as I was also midfield downwind; I announced breaking out of the pattern; and since I was in a high wing airplane; I elected to descend from 1;000 feet to 700 feet and break out away from the airfield. In reality; aircraft Y was due north of jzi for runway 9; so he was not downwind; but angling 45 degree to arc to final. What he was calling downwind was actually 5 NM north angling toward the airfield. As a result of my turning away from the field; it placed the two airplanes at a head on scenario; with me a couple of hundred feet lower and offset to the east approximately 1/2 mile.this airfield has heavy corporate jet traffic mixed in with light airplanes and instruction. Understandably; the corporate traffic does not adhere to traffic pattern procedures; but tend to fly straight ins and modified patterns to expedite arrivals. However; all this conflict could have been avoided if aircraft Y's pilot would have not 'pretended' to be flying a standard pattern; but announced his actual position. Bra (bearing; range; and altitude) would have reduced the midair collision potential significantly instead of flying a 45 degree to the field and calling himself downwind. I have flown [military fighters]; worked for a major airline; and flown light airplanes for [many] years: this was in the top 5 most dangerous non-combat situations I have been in. It was all due to intentional misinformation by a corporate jet trying to make it look like he was abiding by the rules.

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Original NASA ASRS Text

Title: C172 instructor pilot reported an induced airborne conflict with a corporate jet due to inaccurate position reports while inbound to the airport.

Narrative: Performing a biennial flight review; we were performing pattern work to a touch and go. On mid field downwind; Aircraft Y announced (exact verbiage): 'Aircraft Y; midfield left downwind for a right 45 degree; Runway 09' (I don't even know what that means?) As I was also midfield downwind; I became very concerned. I requested DME to field from Aircraft Y; but he responded; 'midfield downwind'. Again; as I was also midfield downwind; I announced breaking out of the pattern; and since I was in a high wing airplane; I elected to descend from 1;000 feet to 700 feet and break out away from the airfield. In reality; Aircraft Y was due north of JZI for Runway 9; so he was not downwind; but angling 45 degree to arc to final. What he was calling downwind was actually 5 NM north angling toward the airfield. As a result of my turning away from the field; it placed the two airplanes at a head on scenario; with me a couple of hundred feet lower and offset to the east approximately 1/2 mile.This airfield has heavy corporate jet traffic mixed in with light airplanes and instruction. Understandably; the corporate traffic does not adhere to traffic pattern procedures; but tend to fly straight ins and modified patterns to expedite arrivals. However; all this conflict could have been avoided if Aircraft Y's pilot would have not 'pretended' to be flying a standard pattern; but announced his actual position. BRA (Bearing; Range; and Altitude) would have reduced the midair collision potential significantly instead of flying a 45 degree to the field and calling himself downwind. I have flown [military fighters]; worked for a major airline; and flown light airplanes for [many] years: this was in the top 5 most dangerous non-combat situations I have been in. It was all due to intentional misinformation by a corporate jet trying to make it look like he was abiding by the rules.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.