Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Confusion; Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Unstabilized Approach; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance
ATC Equipment / Nav Facility / Buildings; Human Factors; Procedure
While on approach to CVG ILS RW 18L we experienced a low altitude alert from CVG Tower. We were conducting a 'Visual' backed up by the ILS 18L and cleared for the ILS 18L. We had visual contact with the runway however elected to not call the field insight due to rain moving between us and the field. Approximately 2;000 feet MSL we lost momentary visual contact with the runway at that time I noticed that it appeared that I was above the glide slope. As I was cleared and on the ILS approach I continued the approach and corrected by lowering my angle of attack to maintain the descent. I then noticed that there was no GS indication and no GS Flag. ATC at the same time issued a 'Low Altitude Alert' I immediately leveled my attitude and was approximately 1;600 MSL and above the MDA minimums for 18L LOC (GS OUT) Almost the same time my First Officer (FO) called the runway in sight as tower also said they had us in sight. We were slightly below the flight path according to the PAPI but in a safe position to land; with over 10 miles of visibility and I elected to continue the approach to landing.ILS was 'NOTAMed out' according to CVG Tower; however the ATIS showed 'SIMUL APPROACHES IN USE. EXPECT ILS APPROACH TO; RUNWAY 18L; RUNWAY 18C; RUNWAY 18R.' We were also cleared by CVG Approach for the ILS 18L Approach. We did see in our release that the ILS 18L showed GS OTS. However we pulled up multiple ATIS reports and there was no mention of it. We were cleared for the ILS and never told GS out. While conducting the approach ATC asked 'how it looks for a visual.' We told him that there was mist/rain that looked like it was moving towards the runway and then cleared us for the ILS 18L approach. When listening to ATC after our approach; ATC said that they showed it as 'Green' and working however other aircraft after us also didn't receive a signal and were issued to go around and set up for the LOC only approach. We only lost visual of the runway for what seems like a couple seconds; and were on the LOC/ILS approach; however if I was to do this approach again I would have executed a missed approach the second I lost contact with the field due to the fact that we didn't have positive vertical guidance. All three happened at what seemed the same time as the wall of water wasn't very wide. Contributing factors was the fact ATC was trying to get us in before visibility conditions at the airport deteriorated. They issue us a vector that put us at the final approach fix higher than normal and though we were configured; increased the chances for an unstable approach. I believed ATC thought we would accept a Visual approach but after we told him about the rain he issued as the ILS clearance.
[Report Narrative Contained No Additional Information].
The uncertain status of the Runway 18L ILS glideslope contributed to receipt of a low altitude alert from the Tower for a flight crew flying an approach visually although technically cleared for the ILS. The alert came as they flew through a heavy rain shower; which momentarily blocked their vision of the runway.