Narrative:

A B737 reported the airport in sight approximately 10 northeast of the airport. This caused an adjustment to the sequence from this aircraft being number 3 to it now being number 1 ahead of 2 other aircraft; one inbound from the west and the other inbound from the southeast. To ensure proper spacing on final; the B737 was instructed to 'maintain at or above 030 until base; turn base within 7 DME; cleared visual approach runway 2'. As the B737 was reading back this clearance; another aircraft; a helicopter checked in on another frequency blocking the read back of the B737. To ensure the read back from the B737 was complete and accurate; I repeated the clearance and had the B737 repeat the read back. The helicopter was a VFR helicopter; checking in over mcgregor point; inbound to ogg. I proceeded to issue the helicopter a squawk for radar identification. By the time the helicopter was radar identified; the B737 had started his base turn and was now head-on with the helicopter at the same altitude. When I attempted to re-restrict the B737; the aircraft did not respond. After another attempt; there was still no response. I then issued the helicopter the traffic and this aircraft reported the B737 in sight. I then called ogg tower and the tower said that the B737 was on their frequency. I advised the tower that the helicopter had the B737 in sight. This aircraft had gone over on its own. The main problem that led to this event; and many similar events that occur on a daily basis; is the fact that the procedures were established based on ogg approach operating as 2 different sectors. R9 is designed to work all arrivals and R10 is designed to work all departures. When working these positions combined; all IFR (both arrivals and departures) aircraft are on one frequency. This works well when all you have to work is IFR traffic. But this is hardly ever the case when working maui approach which is designated as class charlie airspace; requiring VFR aircraft to check-in and establish communication prior to entering the airspace. You would think this would be enough to ensure VFR aircraft stay away from the IFR aircraft operating in the charlie airspace; but not in the case of ogg approach; where the airspace just east of mcgregor point is not charlie airspace but is right along the final approach course. The issue is that an aircraft can be outside of the designated charlie airspace and still; because of the close proximity to final; be a factor for an IFR aircraft on a visual approach or even the ILS runway 2. Because you never know when these aircraft are going to check in; they constantly block transmissions. The best recommendation is to have maui approach operate as 2 sectors from 9 am to 5 pm everyday when VFR traffic is most likely to interfere with all of the arriving IFR traffic and frequency congestion and 'stepping on' and 'blocking' would be greatly reduced.

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Original NASA ASRS Text

Title: HCF Controller described a conflict event between an IFR and VFR aircraft listing combined position procedures as a contributing factor.

Narrative: A B737 reported the airport in sight approximately 10 northeast of the airport. This caused an adjustment to the sequence from this aircraft being number 3 to it now being number 1 ahead of 2 other aircraft; one inbound from the west and the other inbound from the southeast. To ensure proper spacing on final; the B737 was instructed to 'maintain at or above 030 until base; turn base within 7 DME; cleared Visual Approach Runway 2'. As the B737 was reading back this clearance; another aircraft; a helicopter checked in on another frequency blocking the read back of the B737. To ensure the read back from the B737 was complete and accurate; I repeated the clearance and had the B737 repeat the read back. The helicopter was a VFR helicopter; checking in over McGregor point; inbound to OGG. I proceeded to issue the helicopter a squawk for RADAR identification. By the time the helicopter was RADAR identified; the B737 had started his base turn and was now head-on with the helicopter at the same altitude. When I attempted to re-restrict the B737; the aircraft did not respond. After another attempt; there was still no response. I then issued the helicopter the traffic and this aircraft reported the B737 in sight. I then called OGG Tower and the Tower said that the B737 was on their frequency. I advised the Tower that the helicopter had the B737 in sight. This aircraft had gone over on its own. The main problem that led to this event; and many similar events that occur on a daily basis; is the fact that the procedures were established based on OGG Approach operating as 2 different sectors. R9 is designed to work all arrivals and R10 is designed to work all departures. When working these positions combined; all IFR (both arrivals and departures) aircraft are on one frequency. This works well when all you have to work is IFR traffic. But this is hardly ever the case when working Maui Approach which is designated as Class Charlie airspace; requiring VFR aircraft to check-in and establish communication prior to entering the airspace. You would think this would be enough to ensure VFR aircraft stay away from the IFR aircraft operating in the Charlie airspace; but not in the case of OGG Approach; where the airspace just east of McGregor point is not Charlie airspace but is right along the final approach course. The issue is that an aircraft can be outside of the designated Charlie airspace and still; because of the close proximity to final; be a factor for an IFR aircraft on a Visual Approach or even the ILS Runway 2. Because you never know when these aircraft are going to check in; they constantly block transmissions. The best recommendation is to have Maui Approach operate as 2 sectors from 9 am to 5 pm everyday when VFR traffic is most likely to interfere with all of the arriving IFR traffic and frequency congestion and 'stepping on' and 'blocking' would be greatly reduced.

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.