Beech 1900
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2
Distraction; Situational Awareness
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Aircraft; Human Factors; Chart Or Publication; Airspace Structure
I showed Aircraft X's route to be ONM direct TCS direct FHU. After ONM Aircraft X appeared to proceed direct FHU and not TCS. Weather was impacting the sector and I was dealing with something in the northern half of my sector before I realized Aircraft X was flashing MSAW (Minimum Safe Altitude Warning) with the Mountains. Aircraft X was at his cruising altitude of 12;000 feet and the MIA (Minimum IFR Altitude) around the Magdalena Mountains is 12;800 feet. I immediately gave a vector away from the mountains. I questioned the pilot and he said he was showing the same route and didn't know why his plane turned off route. Once clear of the 12;800 foot MIA I cleared Aircraft X direct on course. I am not sure if the aircraft broke the MIA or not.
ZAB Center Controller observed an aircraft flying off its assigned route and below the Minimum IFR Altitude.