Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 4
Situational Awareness; Communication Breakdown; Training / Qualification
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Human Factors; Airspace Structure; Procedure
The Citation jet was pointed out with Approach and cleared for the RNAV approach direct [fix] at 4000 feet. I told the Radar Controller at least 2 times that the MIA (Minimum IFR Altitude) was 4200 feet prior to the aircraft reaching the fix. The Radar Controller didn't amend the clearance and it appeared the aircraft was at 4000 feet prior to [fix] and below the MIA of 4200 feet. The scale of the map at quick glance could have appeared to the Radar Controller that [fix] was in a 4000 foot MIA and that's why they took no action.
[Report narrative contained no additional information.]
A Controller working the Radar Assist position and their trainee reported the Radar Controller allowed an aircraft to descend below the Minimum IFR Altitude even though they advised him of the MIA.