Narrative:

Flight was to kahului. We were given a descent clearance to 8;000. At approximately 9;500 we switched controllers. We called the field in sight and then were told to maintain 9;000. As we were leveling at 9;000 we received a TCAS RA command. 'Descend; descend.' pilot flying disconnected the autopilot and began descending; the command was a full down command. As soon as the pilot flying started to descend we received a 'climb; climb' command. This was also a full scale command. The pilot flying started to climb. As soon as he started to climb we received a 'monitor vertical speed' command. During this event we initially did not see the aircraft on our TCAS. Shortly after we saw the TCAS traffic; it was indicating that it was headed towards us and at our altitude. The highest the TCAS traffic climbed to was 300 feet above our altitude (9;000). I happened to look out the window and was the aircraft very close heading for us and then it made a steep turn to the left (our right). We recognized it as being a cessna caravan. They looked to be approximately 100 yards away from us. If they did not turn it would have been a midair collision. I asked the controller how this had happened. He said that the caravan was VFR traffic and that they were only supposed to be climbing to 8;500. According to our TCAS they climbed through our altitude to approximately 9;300. I checked with the flight attendants to see if the passengers were ok (they were) and to let them know what happened. We proceeded to our destination. I think it occurred because the other aircraft (caravan) deviated from their altitude. They had no idea that we were there. Because of this ATC did not know what they were doing until we almost had a mid air collision. Pilot flying followed the TCAS commands until we were clear of the conflict. First I think we were lucky to have our TCAS. I think without it we may have collided. This has happened many times to me personally with these cessna caravan VFR traffic. I have had to deviate many times because they do not talk to anyone. They fly into departure corridors and depart in the opposite direction as inbound traffic. I feel the only way to be safe from this is for them to be IFR. That way everyone will know what their intentions are and we will have the proper separation. I feel ATC is doing the best they can; however the unknown is these VFR traffic that fly into IFR airspace. Something needs to be done before we have an accident.

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Original NASA ASRS Text

Title: Air Carrier pilots experience a TCAS event at 9;000 FT descending into OGG that initially commands a maximum descent; then reverses and commands a maximum climb. Upon receiving a clear of conflict announcement the traffic is sighted at one to two O'clock and slightly above.

Narrative: Flight was to Kahului. We were given a descent clearance to 8;000. At approximately 9;500 we switched controllers. We called the field in sight and then were told to maintain 9;000. As we were leveling at 9;000 we received a TCAS RA Command. 'Descend; Descend.' Pilot flying disconnected the autopilot and began descending; the command was a full down command. As soon as the pilot flying started to descend we received a 'Climb; Climb' command. This was also a full scale command. The pilot flying started to climb. As soon as he started to climb we received a 'Monitor Vertical Speed' command. During this event we initially did not see the aircraft on our TCAS. Shortly after we saw the TCAS traffic; it was indicating that it was headed towards us and at our altitude. The highest the TCAS traffic climbed to was 300 feet above our altitude (9;000). I happened to look out the window and was the aircraft very close heading for us and then it made a steep turn to the left (our right). We recognized it as being a Cessna Caravan. They looked to be approximately 100 yards away from us. If they did not turn it would have been a midair collision. I asked the Controller how this had happened. He said that the Caravan was VFR traffic and that they were only supposed to be climbing to 8;500. According to our TCAS they climbed through our altitude to approximately 9;300. I checked with the flight attendants to see if the passengers were ok (they were) and to let them know what happened. We proceeded to our destination. I think it occurred because the other aircraft (Caravan) deviated from their altitude. They had no idea that we were there. Because of this ATC did not know what they were doing until we almost had a mid air collision. Pilot flying followed the TCAS commands until we were clear of the conflict. First I think we were lucky to have our TCAS. I think without it we may have collided. This has happened many times to me personally with these Cessna Caravan VFR traffic. I have had to deviate many times because they do not talk to anyone. They fly into departure corridors and depart in the opposite direction as inbound traffic. I feel the only way to be safe from this is for them to be IFR. That way everyone will know what their intentions are and we will have the proper separation. I feel ATC is doing the best they can; however the unknown is these VFR traffic that fly into IFR airspace. Something needs to be done before we have an accident.

Data retrieved from NASA's ASRS site as of July 2013 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.