Tower controller reported raising the awareness of a pc-12's low altitude on the ILS approach. Local...

Narrative:

The field was IFR and visibility was 3/4SM and ceiling overcast at 300 feet. A pilatus (pc-12) was inbound on the ILS talking to the local controller. I advised the local controller that he was really low a little over six miles out. The local controller issued a low altitude alert and I advised the local controller that the aircraft was continuing to descend (he was a 500 feet about five miles out). The local controller told him to execute the missed approach and start climbing. The pc-12 complied and then advised that they were going to break off and go back to [departure airport]. The local controller told him to continue on the missed approach. We properly coordinated with portland TRACON and the TRACON controller advised that they had also had trouble with the pc-12 vectoring him inbound and they believed that it was due to lack of pilot experience.

Original NASA ASRS Text

Title: Tower Controller reported raising the awareness of a PC-12's low altitude on the ILS approach. Local controller issued low altitude alert; followed by clearance to execute a missed approach.

Narrative: The field was IFR and visibility was 3/4SM and ceiling Overcast at 300 feet. A Pilatus (PC-12) was inbound on the ILS talking to the local controller. I advised the local controller that he was really low a little over six miles out. The local controller issued a low altitude alert and I advised the local controller that the aircraft was continuing to descend (he was a 500 feet about five miles out). The local controller told him to execute the missed approach and start climbing. The PC-12 complied and then advised that they were going to break off and go back to [departure airport]. The local controller told him to continue on the missed approach. We properly coordinated with Portland TRACON and the TRACON controller advised that they had also had trouble with the PC-12 vectoring him inbound and they believed that it was due to lack of pilot experience.

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.

Attributes
ACN	1510326
Time
Date	201712
Local Time Of Day	1801-2400
Place
Locale Reference	HIO.Airport
State Reference	OR
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	PC-12
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Route In Use	Other Instrument Approach
Flight Plan	IFR
Person 1
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Tower controller reported raising the awareness of a pc-12's low altitude on the ILS approach. Local controller issued low altitude alert; followed by clearance to execute a missed approach.