Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Inflight Event / Encounter Weather / Turbulence
Flight Crew Executed Go Around / Missed Approach; Flight Crew Diverted; General Maintenance Action
ATC Equipment / Nav Facility / Buildings; Aircraft
I had the airplane all day. I flew two legs before this leg and all navigation equipment worked fine.  Enroute to LGA the flight was going good until the approach into LGA on the ILS 4. The flight crew loaded the ILS 4 into the FMS and set the appropriate localizer frequency. When we were cleared for the approach; I armed the approach and began to fly the ILS to Runway 4 with the automation on. The localizer was moving left to right; I tried to make small corrections which lead into huge corrections on the localizer. I then disconnected the autopilot and the localizer was oscillating left to right even worse. I asked the Tower if the localizer was functioning correctly and the Tower said; 'yes you are the second aircraft having an issue with the localizer you are off course climb to 2000 on present heading' and say intensions. I replied with 'the localizer is left to right we would like to try the approach again.'  We get the vector and commence the approach again. We get cleared for the approach and I arm the approach like the procedure calls for. I leave the automation on to minimums and the localizer was oscillating left to right with the automation on; I manage to fly to minimums on the ILS 4 and the First Officer calls runway insight. We were completely left of course. I was able to see the runway to land but we were high and I didn't want to land unstable so I executed a missed approach for the second time off of the ILS 4 in LGA. Tower says again say intensions. I replied with; 'the localizer is left to right standby.' I told the Tower there is either a problem with the localizer to Runway 4 or the equipment on the airplane. I asked Tower if we can fly the RNAV to Runway 4 and they said it's not authorized. I asked for the ILS to Runway 22 and was told no. I then asked for the VOR to Runway 4. Tower gave us two pilot reports and both aircraft were able to see the runway at 500 AGL; the minimums for the VOR 4 were 560. I decided to fly the VOR 4 hoping to see the runway. I flew the VOR to Runway 4 and the [CDI] was still oscillating but nothing like the ILS (it was still unacceptable). We got to minimums and the runway was not insight; I execute a missed approach to ALB.  Albany's weather was VFR with overcast to broken clouds.  So I fly the ILS to Runway 19 with the automation on to 300 MSL and the localizer works perfectly. This let me know this is an ILS 4 Localizer not the aircraft equipment. Maintenance comes and ops check the airplane good and we launch back to LGA after several hours. This time the winds favored Runway 22 in LGA and the localizer was fine.  I've been employed with the company for 7 years and have flown approaches to minimums; also I've flown the ILS 4 and it's always a problem. I want the company to launch a full investigation on the ILS 4 in LGA even if this means downloading the flight data recorder from my flight before an incident occurs. The company needs to see what the automation was doing on the ILS 4 both times and what the automation did on the ILS to 19 in ALB and back into LGA on the ILS 22. This needs to get addressed. I even called several pilots and asked if they have issues on the LOC to Runway 4 in LGA and all said yes. I have had issue with this localizer before but not this extent.
Air Carrier Captain reports three missed approaches to Runway 22 at LGA; due to oscillating localizer indications on the first two ILS approaches and CDI oscillations on the third (VOR) approach.