Narrative:

On the descent prior to commencing the runway 34L localizer back course into reno; I took the controls. The first officer was low time; therefore was restr from performing takeoffs and landing at reno. While in VMC; the autoplt failed to track the final approach course; as it seemed to be 'fishing' for the course. I disengaged the autoplt and flew it by hand. Around this time; the approach controller issued us an altitude alert and climb up to the MDA. Instead I elected to break off the approach and ask for vectors to bring us back for another approach. On the vectors east of the final approach course headed sbound and at the assigned altitude; a momentary terrain; pull up GPWS alert was annunciated. Being in IMC; we responded to the alert. ATC gave us a higher altitude which put us in VMC. Another approach and landing was performed. Having to unexpectedly disengage the autoplt during the initial phase of the approach; may have caused a high workload of hand flying a non-precision approach with step-downs; thus passing an MDA that otherwise would have been captured by the autoplt. Supplemental information from acn 733337: on approach to reno localizer back course runway 34L. We had been vectored to intercept the localizer back course from the tarvr one arrival. Conditions were clouds at 1000 ft and 8000 ft. Upon receipt on the clearance for the localizer back course we began the descent to wagge and then to giger. The autoplt was not tracking the localizer correctly so the captain disengaged the autoplt. He noted that the command bars were not tracking the course and we lost the course for a few seconds. He proceeded to track the course and the step down descent. Upon crossing giger he continued the descent below 8200 ft. At 7400 ft approach asked us where we were going; and advised that we should be at 8200 ft. Immediately the captain added power and started climbing and asked for vectors around for the localizer back course again. We queried ATC as to the MSA for the sector. It is listed as 9600 ft to the east of fmg and higher to the south. ATC responded that 9000 ft was ok. Headed east we were maintaining 9000 ft waiting for a turn back to the localizer back course when we received a GPWS for terrain. Once the GPWS was activated the captain immediately climbed. ATC queried us as to what we were doing. I advised them of the GPWS warning. ATC asked how high we were climbing and I advised them to 1000 ft. Upon leveling at 1000 ft I asked for our vectors back to the localizer back course. Approach turned us back around for vectors for the localizer back course. The localizer back course 34L was shot again this time with no problems from the autoplt. Upon landing he captain spoke with the tower regarding the loss of the localizer course.

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Original NASA ASRS Text

Title: A CL65 ON APPROACH TO RNO RECEIVED A LOW ALT ALERT.

Narrative: ON THE DSCNT PRIOR TO COMMENCING THE RWY 34L LOC BACK COURSE INTO RENO; I TOOK THE CTLS. THE FO WAS LOW TIME; THEREFORE WAS RESTR FROM PERFORMING TKOFS AND LNDG AT RENO. WHILE IN VMC; THE AUTOPLT FAILED TO TRACK THE FINAL APCH COURSE; AS IT SEEMED TO BE 'FISHING' FOR THE COURSE. I DISENGAGED THE AUTOPLT AND FLEW IT BY HAND. AROUND THIS TIME; THE APCH CTLR ISSUED US AN ALT ALERT AND CLB UP TO THE MDA. INSTEAD I ELECTED TO BREAK OFF THE APCH AND ASK FOR VECTORS TO BRING US BACK FOR ANOTHER APCH. ON THE VECTORS E OF THE FINAL APCH COURSE HEADED SBOUND AND AT THE ASSIGNED ALT; A MOMENTARY TERRAIN; PULL UP GPWS ALERT WAS ANNUNCIATED. BEING IN IMC; WE RESPONDED TO THE ALERT. ATC GAVE US A HIGHER ALT WHICH PUT US IN VMC. ANOTHER APCH AND LNDG WAS PERFORMED. HAVING TO UNEXPECTEDLY DISENGAGE THE AUTOPLT DURING THE INITIAL PHASE OF THE APCH; MAY HAVE CAUSED A HIGH WORKLOAD OF HAND FLYING A NON-PRECISION APCH WITH STEP-DOWNS; THUS PASSING AN MDA THAT OTHERWISE WOULD HAVE BEEN CAPTURED BY THE AUTOPLT. SUPPLEMENTAL INFO FROM ACN 733337: ON APCH TO RENO LOC BACK COURSE RWY 34L. WE HAD BEEN VECTORED TO INTERCEPT THE LOC BC FROM THE TARVR ONE ARR. CONDITIONS WERE CLOUDS AT 1000 FT AND 8000 FT. UPON RECEIPT ON THE CLRNC FOR THE LOC BC WE BEGAN THE DESCENT TO WAGGE AND THEN TO GIGER. THE AUTOPLT WAS NOT TRACKING THE LOC CORRECTLY SO THE CAPT DISENGAGED THE AUTOPLT. HE NOTED THAT THE COMMAND BARS WERE NOT TRACKING THE COURSE AND WE LOST THE COURSE FOR A FEW SECONDS. HE PROCEEDED TO TRACK THE COURSE AND THE STEP DOWN DESCENT. UPON CROSSING GIGER HE CONTINUED THE DESCENT BELOW 8200 FT. AT 7400 FT APCH ASKED US WHERE WE WERE GOING; AND ADVISED THAT WE SHOULD BE AT 8200 FT. IMMEDIATELY THE CAPT ADDED POWER AND STARTED CLBING AND ASKED FOR VECTORS AROUND FOR THE LOC BC AGAIN. WE QUERIED ATC AS TO THE MSA FOR THE SECTOR. IT IS LISTED AS 9600 FT TO THE EAST OF FMG AND HIGHER TO THE SOUTH. ATC RESPONDED THAT 9000 FT WAS OK. HEADED EAST WE WERE MAINTAINING 9000 FT WAITING FOR A TURN BACK TO THE LOC BC WHEN WE RECEIVED A GPWS FOR TERRAIN. ONCE THE GPWS WAS ACTIVATED THE CAPT IMMEDIATELY CLBED. ATC QUERIED US AS TO WHAT WE WERE DOING. I ADVISED THEM OF THE GPWS WARNING. ATC ASKED HOW HIGH WE WERE CLBING AND I ADVISED THEM TO 1000 FT. UPON LEVELING AT 1000 FT I ASKED FOR OUR VECTORS BACK TO THE LOC BC. APCH TURNED US BACK AROUND FOR VECTORS FOR THE LOC BC. THE LOC BC 34L WAS SHOT AGAIN THIS TIME WITH NO PROBS FROM THE AUTOPLT. UPON LNDG HE CAPT SPOKE WITH THE TWR REGARDING THE LOSS OF THE LOC COURSE.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.