ZLC controller reported an IFR aircraft on an airway went below an mia.

Attributes
ACN	1547107
Time
Date	201806
Local Time Of Day	1801-2400
Place
Locale Reference	ZLC.ARTCC
State Reference	UT
Aircraft 1
Make Model Name	Small Aircraft Low Wing 2 Eng Retractable Gear
Flight Phase	Cruise
Route In Use	Airway V101
Flight Plan	IFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 13
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

The aircraft was enroute to ogd via airways. I misunderstood which airway the aircraft was on after byi. I mistakenly thought he was going over mld and was well above the minimum IFR altitude (mia). I had a D side trainee on his first sector working the D side. As the aircraft was approaching byi; he stood up and looked at the chart; then sat back down. He didn't say anything so I again mistakenly thought everything was ok. The aircraft entered an mia of 113 while level at 110. Don't trust that D side is helping at all. Double check all routes and altitudes/meas/mias.

Original NASA ASRS Text

Title: ZLC Controller reported an IFR aircraft on an airway went below an MIA.

Narrative: The aircraft was enroute to OGD via airways. I misunderstood which airway the aircraft was on after BYI. I mistakenly thought he was going over MLD and was well above the Minimum IFR Altitude (MIA). I had a D side trainee on his first sector working the D side. As the aircraft was approaching BYI; he stood up and looked at the chart; then sat back down. He didn't say anything so I again mistakenly thought everything was ok. The aircraft entered an MIA of 113 while level at 110. Don't trust that D side is helping at all. Double check all routes and altitudes/MEAs/MIAs.

Data retrieved from NASA's ASRS site 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.