Baron 58/58TC
Air Traffic Control Developmental
Communication Breakdown
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Equipment / Tooling
I was receiving On the Job Training at the time. An inbound flight plan printed out for Aircraft X; filed TARDE direct ITO at altitude 9000. Before posting the strip; I underlined the TARDE estimate in red to remind myself to scan the radar scope for the target (since there is normally very little traffic in this area); and underlined the destination in red. I expected that our sector would radar identify the aircraft when it checked in; and provide radar vectors before handing off to ITO approach. ZOA called to transfer the aircraft a while later; and I notated the acceptance of the transfer on the strip.I was relieved before the aircraft checked in. During the relief briefing; I mentioned that we had one inbound over TARDE going to ITO as part of my traffic briefing.After I returned from my break; a supervisor informed me that after the aircraft checked in; communications were intermittent; and not fully established. Following a handoff and frequency switch to Sector 5; communications were lost and the aircraft was not vectored before possibly entering a 10000 Minimum IFR Altitude (MIA) at 9000. I was also told that radio coverage in that area is poor. It was suggested to me that I should reroute low altitude oceanic inbounds in that area to ITO via TARDE direct WILYE direct.My expectations of the nature of service we would provide to the aircraft (radar vectors) were based on the premise of having the ability to communicate with the pilot. Areas where we provide air traffic service in the NAS should have good radio coverage. This is especially true if the area is adjacent to possible safety hazards; such as terrain.I recommend the installation/upgrade of radio equipment that would allow for better radio coverage in the area south of the Big Island (Hawaii). This specifically refers to the triangular airspace of Sector 7 that is bordered by Sector 2 on the west; Sector 5 on the north and NE; and parts of ITO Approach on the NE.In the interim; procedures should also be established for receiving aircraft we expect to encounter communications difficulties with. This should include specific locations and options for mitigation (e.g. reroute options).
HCF TRACON Developmental reported an aircraft got below Minimum IFR Altitude on approach to ITO airport.  Radio coverage in the HCF areas were cited as contributed factor.