Narrative:

[We] approached lake havasu from the east with a pilot (flying pilot) that just bought a new comanche; also had another instructor in the back seat. Winds were basically calm. Calm wind runway is 32. [We] called about 8 miles out and announced intentions to cross over midfield for the left downwind for [runway] 32. [We] heard a helicopter on crosswind and another plane that had just taken off; didn't hear any other traffic. Called at 3 miles and again over the top of the airport stating intentions to enter left downwind for 32. Called high left downwind as it is necessary to descend rapidly due to a mountain east; called left base; called turning final. At this time there was no other radio traffic from our report 3 east of the airport. After turning final we hear a centurion call that he was 4 mile final. The pilot was working on slowing the comanche down as this was his first landing in it so I took over the radio and asked where the centurion said he was. We had no idea there was anyone else even in the airport area. Centurion pilot said he was about 3 mile final. At this point I thought we were about 1 mile final so I didn't think it was a big deal other then I was wondering where this other airplane had come from since we hadn't heard him talking. I responded and said we were about 1 mile final for 32. About 5 seconds later I heard him say he was going to do a 360 on final; didn't hear anything else from him. I figured he was faster than us and needed a 360 for spacing; but never saw him. After landing; the pilot in the centurion happened to be parking near us and came over and said we almost hit him by a hundred feet from the top. We never saw him at all and there were three of us in the plane looking. I mentioned we had called our entire traffic pattern. He didn't say anything and walked away. I mentioned as he was walking away that this is probably the reason straight-ins are prohibited on 32 at havasu and his response was he was on the RNAV 32 approach. I spent much time thinking about it. The other pilot was mad because he saw us (turns out we were faster then him). We also would have been mad if we had seen him. But we never saw him. The comanche 260C has an extended nose. It is very long and you can't see anything in front and underneath you which is where he was. The centurion is a high wing plane so he didn't see us until we passed him. It was a situation of both being in a bad place at a bad time. But how did he end up there? I deduced he was on an instrument flight plan and had been talking to center and was released somewhere at the last minute to fly a visual and switch over to CTAF. My guess is that he did that and then called the 4 mile final which was probably a little closer then 4 miles. Since we were high and descending we were going fast; just like he would have been descending on the approach. He probably did not hear our radio calls until the last call on final. If he made any calls before his 4 mile final we didn't hear them so if he did they were probably before we called 8 miles east (the approach is rather long at hii). So neither of us heard each other until we were on final and then we had the classic long nose low wing on top of the high wing. The procedure of turning an IFR aircraft over to CTAF right before the airport area; especially since most approaches are straight in; is one that has kept me up at night. I do not like being the guy on the approach going into an uncontrolled field on a straight in; especially when there is VFR traffic in the pattern. It sets up this exact situation. Lake havasu airport is so busy it needed a tower years ago. But that was not a big factor here other than a tower could have advised each of us about the other traffic. Otherwise I'm not sure what more either one of us could have done. Thankfully we didn't hit.

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Original NASA ASRS Text

Title: PA24 Instructor with two other pilots on visual approach to HII experiences a NMAC with a C210 on the RNAV approach. The Cessna pilot sights the Piper above and moving ahead and does a 360.

Narrative: [We] approached Lake Havasu from the east with a pilot (flying pilot) that just bought a new Comanche; also had another instructor in the back seat. Winds were basically calm. Calm wind runway is 32. [We] called about 8 miles out and announced intentions to cross over midfield for the left downwind for [Runway] 32. [We] heard a helicopter on crosswind and another plane that had just taken off; didn't hear any other traffic. Called at 3 miles and again over the top of the airport stating intentions to enter left downwind for 32. Called high left downwind as it is necessary to descend rapidly due to a mountain east; called left base; called turning final. At this time there was no other radio traffic from our report 3 east of the airport. After turning final we hear a Centurion call that he was 4 mile final. The pilot was working on slowing the Comanche down as this was his first landing in it so I took over the radio and asked where the Centurion said he was. We had no idea there was anyone else even in the airport area. Centurion pilot said he was about 3 mile final. At this point I thought we were about 1 mile final so I didn't think it was a big deal other then I was wondering where this other airplane had come from since we hadn't heard him talking. I responded and said we were about 1 mile final for 32. About 5 seconds later I heard him say he was going to do a 360 on final; didn't hear anything else from him. I figured he was faster than us and needed a 360 for spacing; but never saw him. After landing; the pilot in the Centurion happened to be parking near us and came over and said we almost hit him by a hundred feet from the top. We never saw him at all and there were three of us in the plane looking. I mentioned we had called our entire traffic pattern. He didn't say anything and walked away. I mentioned as he was walking away that this is probably the reason straight-ins are prohibited on 32 at Havasu and his response was he was on the RNAV 32 approach. I spent much time thinking about it. The other pilot was mad because he saw us (turns out we were faster then him). We also would have been mad if we had seen him. But we never saw him. The Comanche 260C has an extended nose. It is very long and you can't see anything in front and underneath you which is where he was. The Centurion is a high wing plane so he didn't see us until we passed him. It was a situation of both being in a bad place at a bad time. But how did he end up there? I deduced he was on an instrument flight plan and had been talking to Center and was released somewhere at the last minute to fly a visual and switch over to CTAF. My guess is that he did that and then called the 4 mile final which was probably a little closer then 4 miles. Since we were high and descending we were going fast; just like he would have been descending on the approach. He probably did not hear our radio calls until the last call on final. If he made any calls before his 4 mile final we didn't hear them so if he did they were probably before we called 8 miles east (the approach is rather long at HII). So neither of us heard each other until we were on final and then we had the classic long nose low wing on top of the high wing. The procedure of turning an IFR aircraft over to CTAF right before the airport area; especially since most approaches are straight in; is one that has kept me up at night. I do not like being the guy on the approach going into an uncontrolled field on a straight in; especially when there is VFR traffic in the pattern. It sets up this exact situation. Lake Havasu airport is so busy it needed a Tower years ago. But that was not a big factor here other than a Tower could have advised each of us about the other traffic. Otherwise I'm not sure what more either one of us could have done. Thankfully we didn't hit.

Data retrieved from NASA's ASRS site as of April 2012 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.