INITIALLY CLRED FOR A VISUAL APCH CRJ100 FLT CREW REQUESTED VOR DME DUE TO VISIBILITY CONCERNS. AN UNSTABILIZED VOR DME APCH REQUIRES CREW TO EXECUTE A MISSED APCH; GPWS ACTIVATED ON DOWNWIND. AFTER REESTABLISHING TWICE THEY LANDED ON THE VOR DME APCH.

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THIS FLT WAS PART OF THE LAST 2 SEGMENTS OF A 17 HR TWO-DAY TRIP. BOTH DUTY DAYS EXCEEDED 13 HRS. A LINE CHK AIRMAN IN THE JUMPSEAT WAS CONDUCTING A LINE CHK. FO WAS PF. ON INITIAL APCH TO ROA; WE WERE GIVEN VECTORS TO A R-HAND DOWNWIND FOR A VISUAL APCH TO RWY 24. ALTHOUGH ATIS RPTED 7000 FT CEILINGS AND 7 MI VISIBILITY; WX WAS POOR WITH TSTMS IN THE AREA AND HAZE. INFLT VISIBILITY WAS MARGINAL AND IN MY ESTIMATION ABOUT 4 MI. ESTABLISHED DOWNWIND AT 4200 FT; THE FO WAS DOUBTFUL ABOUT BEING ABLE TO KEEP THE RWY ENVIRONMENT IN SIGHT THROUGHOUT THE VISUAL APCH PROC. FROM WHERE I WAS SITTING; I WAS UNABLE TO SEE THE RWY. REQUESTED VECTORS FOR THE VOR DME-A APCH TO RWY 24. PROPER NAV RADIOS WERE SET UP FOR THE APCH AND IDENTED. A GOOD CLR IDENT WAS RECEIVED BUT THE SIGNAL WAS A BIT ERRATIC; YET WITHIN LIMITS. WE FLEW THE APCH AND WHEN THE RWY ENVIRONMENT CAME INTO SIGHT; I INSTRUCTED THE FO TO INCREASE HIS RATE OF DSCNT BECAUSE WE WERE TOO HIGH. I SOON REALIZED THAT WE WOULD NOT BE ABLE TO CONTINUE A STABILIZED APCH TO A LNDG AND COMMANDED THE FO TO GO AROUND. ON THE MISSED; ATC CLRED US TO 2000 FT ON A HDG OF 200 DEGS. ATC ALSO CLRED US TO A L-HAND TFC PATTERN FOR A VISUAL APCH TO RWY 24. I WAS CAUGHT UP RECONFIGURING THE ACFT AND PERFORMING REQUIRED CHKLISTS. I REALIZED THAT WE FLEW LONG ENOUGH ON A 200 DEG HDG AND ASKED THE FO TO COMMENCE HIS DOWNWIND LEG. I WANTED US TO KEEP A TIGHT PATTERN DUE TO THE MOUNTAINOUS TERRAIN. I CALLED THE FLT ATTENDANT AND GAVE HER A QUICK BRIEFING ON THE SITUATION AND ASKED HER TO ADDRESS THE PAX. ESTABLISHED ON DOWNWIND AND AT 2000 FT WE RECEIVED A GPWS CAUTION 'TERRAIN' AURAL AND VISUAL ALERT MESSAGE. A CFIT ESCAPE MANEUVER TO MSA WAS INITIATED AND RPTED TO THE TWR. TWR ASKED FOR OUR INTENTIONS AND WE REQUESTED VECTORS TO THE VOR DME A APCH. WE CONTACTED APCH AND WERE GIVEN AN ALT OF 4200 FT. UPON RECEIVING THIS CLRNC WE WERE ALREADY ABOVE 4200 FT SO A DSCNT WAS INITIATED. I RAN THROUGH ALL REQUIRED CHKLISTS. ON FINAL APCH AND OUTSIDE OF THE FAF ON THE VOR DME A; APCH CTL QUERIED ABOUT OUR POS. I BELIEVE ATC SAID WE WERE 2.5 MI S OF COURSE. WE VERIFIED OUR EQUIP AND ALL AVAILABLE INFO AND DETERMINED THAT WE WERE ON COURSE. VOR SIGNAL CONTINUED TO BE WEAK; BUT WITHIN LIMITS. INFORMED ATC WE SHOWED ON COURSE; BUT BECAUSE OF DISCREPANCY; WE WANTED TO BREAK OFF THE APCH. WE DISCUSSED OUR OPTIONS AND BEGAN TO THINK ABOUT OTHER POSSIBILITIES (FUEL 5000+ LBS). THIS WOULD BE OUR LAST TRY. THE FACT THAT A LINE CHK AIRMAN WAS WATCHING ADDED UNNECESSARY STRESS. ON UPWIND THE FO HAD THE WRONG SOURCE SELECTED ON THE FCP (FLT CTL PANEL) BUT CAUGHT IT BEFORE IT BECAME AN ISSUE. ON DOWNWIND AT 4200 FT THE FO AGAIN INDICATED THAT HE WOULD NOT BE ABLE TO MAINTAIN VISUAL. WE ASKED FOR VECTORS TO THE VOR DME A. ON APCH; ATC TOLD US WE WERE ON COURSE. AFTER RECEIVING LNDG CLRNC; TWR COMMUNICATED 'ALT ALERT.' 'ACR XXX; VERIFY YOUR ALTIMETER AND 3200 FT.' WE DID AND THE CORRECT ALTIMETER WAS SET AND WE WERE AT 3200 FT. WE CONTINUED APCH AND LANDED SAFELY. WHILE TAXIING; WE HEARD TWR ALSO GIVING AN ALT ALERT TO ANOTHER INBOUND ACFT. SUPPLEMENTAL INFO FROM ACN 703013: AFTER RPTING OUR CFIT ENCOUNTER TO TWR; WE WERE TURNED OVER TO ROA APCH. THEY INSTRUCTED US TO LEVEL OFF AT 4200 FT. BY THAT TIME WE WERE ABOVE 4200 FT AND HAD TO DSND. AFTER WE HAD LEVELED BACK AT 4200 FT; THE CAPT WAS TALKING WITH ROA APCH WHEN I REALIZED THAT OUR FLAPS WERE STILL 8 DEGS. MY TIMING WAS OPPORTUNE AS WE WERE STILL BELOW 215 KTS. IN HASTE; WE HAD NEGLECTED TO PROPERLY RECONFIGURE THE FLAPS TO 0. ANOTHER SET OF VECTORS WAS PROVIDED TO THE APCH. IT WAS EVIDENT ATC WAS TAKING US OUT FURTHER PAST THE FAF THAN THE PREVIOUS TIME. PROPERLY CONFIGURED; WE PROCEEDED INBOUND TOWARDS THE FAF. ATC THEN QUERIED AS TO WHETHER WE WERE ON COURSE. CHKING OUR INSTS AND RELEVANT DATA; WE DETERMINED WE WERE ON COURSE. THE ODR VOR WASN'T HELPING; IT WAS BOBBLING AROUND ON EITHER SIDE OF COURSE ABOUT 3 DEGS. IT WAS WITHIN OUR LIMITS SO WE RESPONDED THAT WE WERE SHOWING ON COURSE. ATC SHOWED US S OF COURSE. BECAUSE OF THE DISCREPANCY; THE CAPT ELECTED TO ABORT AND WE INITIATED ANOTHER MISSED APCH FROM 4200 FT. WORKLOAD FROM CONSTANT FLOW OF CHKLISTS WAS WEIGHING ON ME. CONTEMPLATED DIVERTING TO GSO OR CHO (HAD PLENTY OF FUEL 5000+ LBS). IN PROCESS OF EXECUTING MISSED APCH; NOTICED NAV MODE WAS STILL ENGAGED. PROMPTLY CORRECTED ERROR AND RESUMED LATERAL NAV IN HDG MODE. AGREED TO TRY ONE MORE TIME FOR APCH TO RWY 24. WE WERE VECTORED AT 4200 FT; HAD ARPT IN SIGHT; BUT LOST IT AGAIN IN THE HAZE. REQUESTED AND WERE GRANTED VECTORS FOR THE APCH. CONFIGURED; AND ATC SHOWED US ON COURSE; MATCHING OUR READINGS. ODR VOR WAS BOBBLING SLIGHTLY ON THE CDI BUT WAS WITHIN LIMITS. I BELIEVE THIS NAVAID'S ACCURACY NEEDS TO BE INVESTIGATED. APCH RESULTED IN VISUAL ACQUISITION OF THE RWY ENVIRONMENT. LNDG FOLLOWED BY TAXI IN TO THE GATE.