Commercial Fixed Wing
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Ground Event / Encounter Ground Equipment Issue
Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem
ATC Equipment / Nav Facility / Buildings
We were on the ILS 09R at PHL approximately 15 DME when the Localizer exhibited erratic deviations on both the Captain and First Officers  Primary Flight Displays. The Flight Director and Auto Pilot was engaged and attempted to 'chase' the course which started to worsen the situation. ATC advised us that we appeared to be about a mile south of the localizer course; slightly less than 1/2 dot deflection at this point. The First Officer disengaged the autopilot and hand-flew the approach with no further issue. The deviation appeared to subside as we got closer to the field and we were within stable approach parameters from the Final Approach Fix until touchdown. Also; the NAVAID had been positively tuned/identified per company SOP prior to commencing the approach. Course deviation on the HSI followed by ATC advising us that we were right of course. Unreliable Localizer signal at PHL which is apparently a known issue.The First Officer disconnected the autopilot and hand flew. I notified maintenance and was told by multiple maintenance personnel both on the phone and in person at the aircraft that this was a known issue with runway 09R; it happens all the time; and that there's a NOTAM in effect regarding the issue. I searched all of the NOTAMs  and could not find anything remotely related to unreliable LOC/ILS on 09R. I do not believe that the FAA would allow a malfunctioning NAVAID to remain in service and do not think there is any merit in the maintenance department's claim that this is a known problem that we should just accept and learn to deal with. However; if there is a known problem with this or any other NAVAID that necessitates a procedure change; then the company should disseminate that information to the pilot group with an FIL; etc.
An Air Carrier pilot reported the PHL Runway 09R Localizer is unreliable and caused a course deviation. The reporter stated maintenance personnel told him it was a known issue and a NOTAM was published but their are no NOTAM's addressing this issue.