Date: 201505
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 15
Light: Daylight
Aircraft: DA20-A1 Katana
Operator: FBO
Operating under: Part 91
Flight plan: VFR
Mission: Training
Flight phase: Final Approach
Airspace: Class G ZZZ
ATC / advisory: CTAF ZZZ
Reporter organization: FBO
Reporter function: Pilot Flying; Trainee
Reporter qualification: Flight Crew Student
Human factors: Communication Breakdown; Other / Unknown
Second reporter function: Instructor; Pilot Not Flying
Anomaly: Conflict NMAC
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: We had been doing pattern work; we were on our third landing. We made radio calls on downwind; base and final; while looking for traffic. On final we were on glide slope for 36 when all of a sudden I see a crop duster plane off to my left make a sharp left turn to avoid hitting us. We did a go around and departed to the northwest to head back to our home airport.


Second narrative: My pre-private student and I had flown from our home airport to practice landings and non-towered operations. We made appropriate position reports and entered left downwind for Runway 36. While on final for our second touch and go we observed a yellow crop dusting aircraft fly over the center of the runway at approximately 500 AGL; then turn directly into a very very tight left downwind for 36. This aircraft did not make position reports; and of course may not have had a radio to hear our reports. We completed a touch and go on the runway; and when we returned to downwind we saw the aircraft taxi clear of the runway and to a ramp area with several large trucks; presumably to refill for another mission. After making a normal pattern at 1500 MSL; we made our way to final for another landing. We observed no traffic on the runway; on final; or ahead of us. At approximately 200 AGL a second yellow crop dusting aircraft descended towards final from above us and behind us; overtaking us and momentarily establishing a position approximately 50 feet ahead and to the left of our aircraft; also established on glide slope for landing; before making a sharp left bank to avoid a collision. We waited until clear; executed a go around; departed the area straight ahead while climbing; then proceeded northwest to return to our airport. After observing the first aircraft my student and I specifically discussed that some aircraft do not have radios and that making reports in the pattern is not required at non-towered airports; and reminded the student that vigilant scanning was necessary. Neither myself nor the student believe we could have avoided the situation. I believe that we followed the exact procedure from the AIM for non-towered airports; we both were aware to look for traffic; and in particular I was looking for traffic while the student was landing. I believe that the other two aircraft were conducting unsafe operations that have been observed in crop dusting operations in an attempt to save time.


Synopsis: DA20 Instructor with student experience a NMAC with a crop duster at low altitude on final approach. Evasive action is taken by the crop duster and the DA20 crew goes around and returns to their home field.