Date: 201701
Local time of day: 1201-1800
Location: ORF.Airport, VA
Flight conditions: IMC
Weather elements / visibility: Turbulence
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class C ORF
ATC / advisory: Tower ORF
Aircraft component: ILS/VOR
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Weather / Turbulence
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Aircraft Equipment Problem Dissipated; Flight Crew Diverted; Flight Crew Executed Go Around / Missed Approach; General Maintenance Action
Contributing factors: Aircraft; Airport; Weather
Primary problem: Ambiguous

Narrative: Pre departure planning was normal except that there were 50 passengers that wanted to board. The gate agent asked how many we could take as she had planned for 47 passengers. We ran the numbers trying to take all passengers; however with our fuel load and the bags; we were limited to 48 passengers. We also found that if we moved people around that we would be out of CG. Our limit was exceeding the landing weight. Burning extra fuel was not an option due to the forecasted weather in ORF. 180@9 P6SM VCSH BKN010.Enroute flight was normal. ATIS for ORF was: 230@8 10 OVC005 12/11 29.77 RWY 23. Additional weather; constant light turbulence and a quartering crosswind on final.We intercepted the localizer in green needles and both ILSs were identified. The autopilot rocked back and forth on the localizer; bouncing a Quarter of a dot out on both sides but seemed to have stabilized the closer we were. At 1000 feet we were stabilized on the approach. The localizer and autopilot seemed to settle down. We were dead on the localizer at 500 feet when it went yellow with no course. We went missed and were given a heading.We set up for our second approach and completed all of our checklist. I briefed that I would hand fly this approach as it may have been a problem with the autopilot. Both ILSs were again ID'd and we intercepted the localizer. The autopilot again began to rock back and forth. I disconnected the autopilot and flew the approach by hand. The Flight director went back and forth a little similar to the first approach but I was able to maintain a better path as the adjustments I made were not as quick or far. At 1000 feet we were again stabilized. I added some speed; (about 5-10kts) for turbulence. The course and Glideslope was dead on to 500 feet when the localizer again went yellow. We again went missed and were given a heading.My First Officer (FO) told ATC that we were going missed. They asked what happened and my FO told him. He said he had two green lights on the ILS and he asked our intentions. I discussed with my FO the possibilities. I did not want to shoot another approach to ORF. PHF was discussed but I assumed it would have similar weather; thereby giving us similar results. We discussed CLT; but they had OVC002 and it would take fuel away from us. ILM was our alternate but it had similar weather; a smaller runway; and was near the coast. I was looking for something inland farther where we had a chance of calmer winds. We decided on ZZZ. We told ATC and we were cleared [to] ZZZ.Weather at ZZZ ATIS was: 270@4 2 1/2m BR ovc004 8/8 29.74At this point my FO set up for the approach and I briefed it choosing RWY XY ILS because it was a longer RWY and would allow us some room for error if needed. I was concerned about our performance of our localizer at that time. I briefly went over in my mind whether it was our equipment or ORF's equipment that was causing the failure. Our options with the weather were limited to an ILS. GPS and VOR approaches did not allow us the opportunity to get below the clouds in our area concerning our equipment issues and fuel remaining; (about 3200 LBS). If our localizer had failed (which I find difficult [to believe] due to having two separate antennas and systems;) my next two options would be to ask for Precision Approach Radar at a local military base; (I am familiar with the procedure;) for which we were not qualified or a constant speed descent GPS below minimums. Neither of which I wanted to attempt.Our approach into ZZZ was coupled and closely monitored ILS RWY XY. There was less turbulence and effect from the wind. We broke out at about 200 feet and landed. We did notify Dispatch via ACARS of the situation. We taxied into the gate. Fuel; about 2800 LBS remaining.I contacted maintenance and let them know the complete situation. I wrote up the issues in the maintenance log and placed [it] on the dashboard. I made an announcement to the passengers of the situation letting them know 'we had diverted due to weather and the plane would not be able to fly again.' I told them I would give them further information as quickly as I could.I contacted scheduling and let them know that the crew would not be able to continue. It was our fourth flight and seventh instrument approach of the day. I contacted the coordinator to inform them of the situation and they were upset with me because they had to fill out paperwork.




Synopsis: CRJ-200 Captain experienced oscillations left and right on the localizer during an ILS to Runway 23 at ORF that gradually diminished. At 500 feet the display went yellow with no course and a missed approach was initiated. The second attempt produced the same result and the crew elected to divert to a suitable alternate. No further problems were encountered.