Date: 201910
Local time of day: 0001-0600
Location: ZSE.ARTCC, WA
Aircraft: S-70/UH-60 Blackhawk/Seahawk/Pavehawk/Knighthawk
Operator: Military
Operating under: Part 91
Flight plan: IFR
Flight phase: Cruise
Airspace: Class E ZSE
ATC / advisory: Center ZSE
Reporter organization: Government
Reporter function: Trainee; Enroute
Reporter qualification: Air Traffic Control Developmental
Human factors: Communication Breakdown; Situational Awareness; Training / Qualification
Second reporter function: Enroute; Instructor
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Air Traffic Control; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: Aircraft X was level flight FL110. At XA:07Z I issued cleared direct DSD VOR track outbound on the procedure turn descend and maintain 090. Aircraft X read back clearance but I went back and reissued after DSD track outbound on the VOR A approach. Aircraft X read this back correctly. At XA:15Z Aircraft X reported established on the approach (5.76 miles west of DSD) I told him 'roger I'll have clearance shortly; descend and maintain 8;000 ft.' at 6.22 miles from DSD. At XA:19Z my trainer confronted Aircraft X about whether he knew he needed to remain within 10 miles of DSD per the approach; Aircraft X said he was aware and that he was waiting for his clearance. She then explained he was supposed to fly the procedure turn as published but maintain 8;000. He responded with ok and that he's making the turn inbound. At 13.7 miles out from DSD my instructor instructed Aircraft X to climb to 110 for terrain; no delay in the climb. He acknowledged. Aircraft X was at 8;000 ft. in a 9;000 ft. MIA outside the boundaries of the approach. I should have issued the climb right away instead of waiting once we knew he was outside the 10 mile parameter of DSD. Also we should have issued a terrain alert. I believe this is a pilot deviation; but we could have issued the climb and safety alert sooner.


Second narrative: I was training Developmental on [sector]. At approximately XA:07Z Aircraft X was cleared direct DSD and told to track outbound on the procedure turn and descend and maintain 9000. He read it back in a roundabout way and Developmental restated 'after DSD track outbound on the VOR A'. At approximately XA:13Z Developmental asked if they were established; to which Aircraft X said something to the effect of no; and they were instructed to report established and maintain 9;000 ft. At about XA:15Z Aircraft X began reporting established (initially about 5.75NM west of DSD when they started reporting established) Developmental rogered them and assigned 8;000 ft. Aircraft X read back 'waiting for the clearance; leaving 9;000 ft. for 8;000 ft.' On FALCON we observed that at about XA:18 that Aircraft X was about 10 nm west of DSD level at 8;000 ft. The VOR-A procedure at RDM states the procedure turn is to remain within 10 nm. of DSD; with a procedure turn altitude at or above 7;900 ft. At approximately XA:19; I questioned Aircraft X about the 10 nm restriction posted on the procedure; to which they responded 'We are aware of the restriction were just waiting for our clearance.' Aircraft X began their turn inbound about 13 miles west of DSD and I climbed him to 11;000 ft. for higher terrain west of his position. We believe that the pilot misunderstood what we expected [of] him with the clearance (and readback) to track outbound on the VOR A procedure; as he didn't turn inbound on the published procedure; which put [him] in in a higher MIA of 8;900 ft. when he was previously on a published route with an MEA of 8;000 ft. If the pilot didn't understand what was expected of him with the clearances given; he should have asked. I suppose we could have kept him as high as the MIAs along his route to attempt to anticipate this happening; but that seems unrealistic; as we tell aircraft to track outbound/inbound on procedures all the time while withholding approach clearances for traffic; spacing; etc.


Synopsis: ARTCC Instructor and Developmental controllers reported a communication breakdown that caused an IFR aircraft to fly below the sector minimum IFR altitude.