AN ACR MD82 FLC GOT OFF COURSE ON A SID; IN PART; BECAUSE OF A MALFUNCTION IN THEIR #1 VOR RECEIVER. THE ALERT DEP CTLR GAVE THEM VECTORS BACK ON COURSE.

Narrative

#1 VOR (WITH #1 DIGITAL FLT GUIDANCE SYS SELECTED TO #1 POS) FAILED ALMOST IMMEDIATELY AFTER TKOF. THERE WERE NO FLAGS/FAILURE INDICATIONS AND VOR CONTINUED TO IDENT AND GIVE ACCURATE DME INDICATIONS. THE FAILURE CAUSED AN OVERFLY OF AN ASSIGNED DEP RADIAL (RIVER 6 DEP). DEP CTL CORRECTED OUR TRACK AND GAVE US A VECTOR TO A SUBSEQUENT FIX. AT THAT TIME WE HAD A CHANCE TO TUNE SEVERAL VOR STATIONS WITH BOTH RADIOS. #1 VOR AND #2 VOR CONSISTENTLY DISAGREED BY APPROX 30 DEGS. A LATER PWR DOWN (PULLING AND RESETTING RESPECTIVE CIRCUIT BREAKER FOR THE #1 VOR) BROUGHT IT BACK TO COMPLETE AGREEMENT WITH #2 VOR AND NO FURTHER PROBS WERE NOTED. PROB WAS ENTERED IN ACFT MAINT LOG. I DO NOT KNOW THE CONCLUSION OF THE MAINT CHKS. IN THINKING THIS OVER; A BETTER WAY TO DO THIS DEP WOULD BE TO HAVE BOTH VOR; ON THE SAME FREQ. (#2 WAS TUNED TO THE NEXT FIX.) WHILE THIS WOULD NECESSITATE SOME QUICK RETUNING IN ORDER TO SET UP THE NEXT FIX; IT WOULD DO A GOOD JOB OF POINTING OUT A FAILURE LIKE THE ONE WE HAD. ALSO; THANKS TO THE PDX DEP CTLR FOR CLOSELY MONITORING OUR TRACK.