Date: 201906
Local time of day: 0001-0600
Location: HCF.TRACON, HI
Flight conditions: VMC
Light: Daylight
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class C OGG
ATC / advisory: TRACON HCF
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Confusion; Situational Awareness
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight; Routine Inspection
Contributing factors: Manuals; Procedure; Company Policy; Chart Or Publication
Primary problem: Procedure

Narrative: OGG changed its RNAV Z Approach to go below the minimum vectoring altitudes.  Once an aircraft is cleared on the RNAV Z; we are unable to vector them off the approach; due to the minimum vectoring altitudes being above the altitude of the approach.  I was under the impression; and I was also told this on a recorded line by a controller at OGG that if an aircraft is on the RNAV Z; OGG Tower would be responsible for separating any departing VFR aircraft from the inbound IFR aircraft on the RNAV Z approach.  I asked if I need to call for each aircraft; and the OGG Tower controller told me that as long as I type in 'RNZ' into the scratch pad; OGG Tower would handle the separation.  OGG Tower typically climbs an aircraft southbound to stop at 1;000 feet; and the altitude on the RNAV Z descends to 1;800 feet.  For a heavy IFR aircraft and a VFR aircraft; a minimum separation of 1;000 feet would be needed.  I assumed; based on my conversation on the recorded line with OGG Tower that they would handle whatever separation would be necessary with any VFR departing off the airport; since I am not made aware of any departing VFR aircraft.  I believed this to be true for every aircraft.  There was never an issue with VFR aircraft being a factor for my IFR inbound on the RNZ until I had an inbound heavy Aircraft X.  I had cleared Aircraft X for the RNAV Z approach; and I was unable to take Aircraft X off the approach; since minimum vectoring altitudes are above the approach altitudes. Then; a VFR aircraft departed off OGG and was switched to me. I called on the shout line and asked what type of separation OGG Tower was giving me with the VFR and my Aircraft X on the RNAV Z approach.  The OGG Tower was unaware of any separation being necessary; and I told him about my conversation with a controller about how they would provide separation.  The OGG Tower Controller denied any knowledge of this; and basically gave me an aircraft that would not be separated from my heavy on the RNAV Z approach.  I told him to have his supervisor call my supervisor and work out something; because it is unacceptable that OGG Tower will provide no separation for the RNAV Z approach.  Either we make OGG Tower separate their VFR traffic from our IFR inbounds on the RNAV Z; or we stop using the RNAV Z approach.  If the approach was made that did not provide separation; then it was a very poor approach to implement.  My question is do I keep using this approach?  Do I stop using this approach?




Synopsis: A HCF Approach controller reported confusion with the Tower over a procedure to separate arriving IFR aircraft from VFR departures.