Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Procedure; Aircraft
In flight; while using VOR navigation we began to have erroneous signals from both Nav1 and Nav2 about 50 miles north of ZZZ [VOR.] ATC was notified and we received radar vectors/direct ZZZ1 [VOR] when able. We assumed at this point based on the indications; it was an issue with the VOR. I was able to positively ID ZZZ1 [VOR] and we began to navigate on our own. ATC cleared us to descend; and as we descended we entered IMC and ice. It was around that time we lost ID on the station and again received unreliable signals from both VOR receivers. We again notified ATC and requested vectors for the remainder of the flight. We descended via radar vectors to the Visual without incident. Prior to conducting a Visual Approach and in visual conditions; the NAV Radio was tuned to the localizer frequency and appeared to be receiving accurate signals. This type of incident could possibly be avoided with further troubleshooting involving MEL with issues concerning VHF navigation. Furthermore the threat could be mitigated with an additional source of navigation.
We planned and plotted our course using terrestrial navigation as our FMS was on MEL for not Auto Tuning and losing VOR redundancy. About 50 miles north of ZZZ [VOR] we started getting erratic signals from both VORs. I tuned in for a Morse Code ID and was not able to get a signal. I advised ATC and they said they would look into the matter and gave us radar vectors to ZZZ1 [VOR] and cleared us direct when able. We were well outside the service volume of ZZZ1 [VOR] as we were about 200 NM northwest of the VOR. As we got within about 100 NM we had a strong clear signal; and a steady course; so we assumed that the ZZZ VOR was the issue. About 50 miles from the VOR we lost all signal and navigation capability. After trying several other VOR's we discovered that we had a NAV problem onboard. We notified ATC and Dispatch immediately. After double checking the weather and determining it was VMC with little chance of that changing; we elected to continue on using ATC radar vectors to a Visual Approach. With some limited troubleshooting it appeared that the VOR's only worked in VMC and would not work at all in icing conditions. A VOR check was completed just three days ago when the aircraft came out of heavy maintenance.This type of incident might have been avoided by requiring more troubleshooting to the MEL for issues relating to VHF navigation. The threats could also be mitigated with a tertiary source of navigation such as an ADF and/or crewmember training on PAR or ASR/SRA approaches.
CRJ-200 flight crew reports accepting an aircraft with the FMC on MEL for not auto tuning VOR's. Enroute it is determined that the VOR's themselves may be the issue and radar vectors are requested to complete the flight.