Date: 201504
Local time of day: 1801-2400
Location: ZAN.ARTCC, AK
Light: Night
Aircraft: Small Aircraft; Low Wing; 1 Eng; Retractable Gear
Flight plan: IFR
Flight phase: Cruise
Airspace: Class E ZAN
ATC / advisory: Center ZAN
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Confusion; Distraction; Situational Awareness; Time Pressure; Troubleshooting
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance
Contributing factors: Procedure; Human Factors; Airspace Structure
Primary problem: Procedure

Narrative: Aircraft X was enroute to ANC via GKN on an IFR flight plan at 160 MSL.  At that altitude the aircraft would have been outside of radar coverage for nearly the entire flight.  The filed route appeared to take the aircraft through several high altitude Minimum IFR Altitudes (MIA)s including FL208; 171; 187; 186 and 163 prior to reaching GKN.  The controller I relieved did not mention any specific issue regarding the aircraft's routing and I did not have an opportunity to ask if they had verified the route was clear of the MIAs.  I called CZEG and advised that I needed the Aircraft X at least at FL200 due to terrain; protecting for the FL187 MIA (local altimeters were below 29.92) and having not yet noticed the 208 MSL MIA as potentially being along the flight path.  The Edmonton controller indicated that they had offered FL200 to the pilot but that he had declined and requested FL160.  I was able to contact the aircraft and; after receiving a position report 156 NM SE of GKN; issued a low altitude alert and instruction to climb to FL 220 immediately.  The pilot responded that he was in VMC conditions; had all the terrain in sight and requested VFR On Top once in U.S. airspace.  The aircraft continued VFR On Top for approximately 15 minutes before canceling IFR and turning direct to ANC.The position report put the aircraft approximately 5 NM East of the FL208 MIA boundary; but because there was no radar coverage I cannot be certain it had not yet penetrated the MIA.  Additionally; CZEG has control authority in that area below FL180 until 140 degrees west; the international boundary.  According to the IFR chart available on sector that airspace is classified as uncontrolled.  On our side of the boundary there is a large area of uncontrolled airspace; but the aircraft's altitude would have presumably placed it in Class E.Because I am not familiar with Canadian procedures in uncontrolled airspace I do not know if they would have a need to be aware of our MIA polygons which lie therein.  Certainly I would think they are aware of the significant terrain that lies on the border but perhaps the minimum IFR altitudes are different in each country.  We do not have access to any such information regarding minimum altitudes in adjacent Canadian airspace.  At a minimum the controller working before me should have verified the routing was clear of the MIA's or have issued a routing to the CZEG controller which would have been so.  Due to the lack of radar and workload if the route is determined to be unsafe after the aircraft departs we are left with few options to route the aircraft around the conflict.




Synopsis: An Anchorage Center (ZAN) Controller reports of receiving information on an IFR aircraft that; because of its altitude; will be below the Minimum IFR Altitudes (MIA). The Controller coordinates with another facility to get the aircraft a higher altitude. When the pilot checks on the Controller issues a low altitude alert and tells the pilot to climb. The pilot says he wants VFR on top and the Controller lets the aircraft remain VFR on top. Controller is concerned about correct procedures for this type of operation.