Small Aircraft; High Wing; 1 Eng; Fixed Gear
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days .5; Flight Crew Total 8000; Flight Crew Type 1150
Communication Breakdown
Conflict NMAC
Flight Crew Took Evasive Action
Airport; Human Factors
EUL has a higher operations count that any other airport in Idaho. It is uncontrolled with a CTAF which is also shared with nearby Nampa airport. It has every aircraft category/class including parachutist who land on the field during peak use times. It also has intensive helicopter training activity filling the south-side traffic patterns and primarily using the south-side parallel taxiway for their landings and hovering.We departed EUL on Runway 30 and conducted air work several miles to the northwest of the airport. We returned to EUL and; after listening to the numerous aircraft in the traffic pattern for Runway 30 as well as the current weather 135.07 indicating a crosswind; we entered right traffic for Runway 30. A Lear 35 was on final for Runway 30 with several helicopters in left traffic for Runway 30 parallel taxiway. The Airport Manager was also on the CTAF advising the Learjet where to park. We accomplished a stop and go and proceeded with right traffic Runway 30 for a second stop and go. We made the usual transmissions and had anti-collision and landing lights on. At about 200-300 feet AGL on final; on visual glide path to Runway 30; both the instructor and I visually acquired a high wing aircraft (Aircraft Y) which had just departed Runway 12 and was now slightly below our altitude at a distance of approximately 2000 feet with a normal nose-up angle climb. Thus we were nose to nose. The Aircraft Y was climbing and appeared to remain on Runway 12 heading. To the right of the conflicting Aircraft Y was a helicopter landing on Runway 30 parallel taxiway. I turned right and continued our descent to give both vertical and lateral separation. After the Aircraft Y had passed to our left and above I applied power to abort the landing because we were well to the right no longer in a position for safe landing in the touchdown zone of Runway 30. I returned to runway heading and we re-entered right traffic for Runway 30 and once again encountered the Aircraft Y well above us this time climbing out of the Runway 12 left downwind while we were at pattern altitude for the right downwind Runway 30.The conflict Aircraft Y [was] difficult to see. We heard no transmissions from the Aircraft Y; and observed no landing light or anti-collision lights. The conflict Aircraft did not appear to make any maneuver to avoid us; and perhaps did not see us because of nose up angle. However Aircraft Y's options were limited by the helicopter to their right and me below and to their left. During this time the CTAF frequency was very active with all the traffic for Runway 30; traffic at Nampa; and also the Airport Manager advising the Learjet on parking. The CTAF frequency is very congested at times. The wind was a direct crosswind from the north which with slight shifts may have been interpreted to favor Runway 12 at times. However with the massive number of helicopters and a several aircraft using Runway 30; it was impossible to overlook the flow of traffic.I make all appropriate radio calls for CTAF and listen intently as well. However some pilots/aircraft using this field do not transmit even if they do have a radio... and this issue has been a topic in a recent airport newsletter. There have been a fair number of similar events at this airport according to the local banter and occasional airport newsletter.  This is one of the most hazardous airports I've ever operated from due to the mix of traffic; the volume of traffic; the non-standard traffic patterns; the excessive use of taxiways for helicopter operations; the CTAF congestion; the minimally equipped aircraft; and the nonprofessional nature of some pilots/operators in general aviation. Attempts by the Airport Manager to improve adherence to known safety techniques seem to fall short. Most likely only an ATC Tower can tame this airport.
Pilot experiences a NMAC on short final for Runway 30 at EUL with an aircraft departing Runway 12. No CTAF report was made by the aircraft departing Runway 12 and the pattern was full of aircraft landing Runway 30. The reporter side steps to the right then goes around.