Date: 201903
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Fatigue; Confusion; Situational Awareness
Second reporter function: Pilot Not Flying; Captain
Anomaly: ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Became Reoriented; Flight Crew FLC Overrode Automation
Contributing factors: ATC Equipment / Nav Facility / Buildings; Human Factors
Primary problem: Ambiguous

Narrative: We were cleared to 2;000 feet from ATC on the approach then cleared for the approach. Glide slope appeared to be working because it was at the correct altitude when it came up. Started to follow it down. We realized that it wasn't working when we saw that we got low and then we started to correct back to our altitude. It was an all-nighter; a little tired by the time we were given clearance to land.If the glide slope is out of service please shut it off so it doesn't lead to another situation like that.


Second narrative: While on a visual approach into ZZZ; landing Runway XX Center; we were cleared to land. The First Officer was flying and was tracking the glide slope. As he was descending; I noticed we were getting low relative to our position with the runway. I had him stop his descent and climb back to our last assigned altitude of two thousand feet. At the same time the Tower Controller also noticed our altitude and issued a climb back to two thousand feet. We discovered the glide slope was [out of service]. It was buried in the ATIS and was missed by both pilots. The indication from the instruments was it was functioning properly. To add to the confusion the PAPI was also inoperative. We used altitude and distance as a glide slope to a safe and uneventful landing.Primary reason was both the First Officer and Captain missing the glide slope [out of service] which was buried in the ATIS. It was a redeye flight which didn't help matters any. I am sure a certain [amount] of tiredness played a factor. We were cleared to a runway that had equipment that was inoperative which exacerbated the problem. At no time was any verbal warning issued by either Approach Control or Tower indicating the inoperative equipment.Make it loud and clear anytime ground based equipment is [out of service]. Don't bury it in all of the ATIS clutter. A reminder from ATC that systems are down would be a great help to a flight crew. Don't clear an aircraft for a visual approach without some vertical guidance to the runway.


Synopsis: A319 flight crew reported following an inoperative glide slope and receiving a low altitude alert from Tower.