Narrative:

On descent into boi, ZLC cleared us from FL240 to 13000' on altimeter 30.48. Boi ATIS received some time prior (5-7 mins) quoted 29.48. Was noted on paper and placed in a dark area forward of the throttle quadrant. Approach control continued our descent and vectored us to a final approach for runway 10R boi, descending to 4200'. At 4200' inbound I dialed in the runway 10R ILS localizer and got a G/south aural warning. G/south indicator was noted full deflection up (this occurred 7-8 mi DME). Approaching the OM the G/south indication was still full deflection up. At that time a missed approach was initiated. Shortly thereafter contact with tower resulted in verification that the ILS was normal on their monitor. Clearance was received to climb to 5000' and vector to downwind. At 5000' approach control asked for confirmation of altitude. We responded 5000'. Control stated their readout was 4200'. I asked for a current altimeter setting and control responded with 29.48. I stated that the altimeter setting issued ot us from slc was 30.48 and asked if there was a warning from his equipment that we were low on our last approach. His response was that everything appeared normal. After resetting our altimeters to 29.48 a normal approach and landing was executed. The cause of this incident was a wrong altimeter setting issued and received by ZLC controller and me. The recommended corrective action involves 2 actions: 1) company descent checklists executed on descent passing 18000' includes an altimeter check. This check should be expanded to include a x-chk of the a) WX briefing message altimeter, B) ATIS altimeter setting, C) controling agency altimeter issued on descent. 2) at 2500' the radio altimeter check should be expanded to include a comparison of the field elevation and aircraft elevation. The different should be approximately 2500', verifying radio altimeter reading.. Supplemental information from acn 13723: subsequent investigation by the company has confirmed that 20.48 was assigned by the ZLC controller.

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Original NASA ASRS Text

Title: ACR WAS 800' LOW ON APCH DUE TO ALTIMETER ERROR BETWEEN ARTCC AND ATIS.

Narrative: ON DSCNT INTO BOI, ZLC CLRED US FROM FL240 TO 13000' ON ALTIMETER 30.48. BOI ATIS RECEIVED SOME TIME PRIOR (5-7 MINS) QUOTED 29.48. WAS NOTED ON PAPER AND PLACED IN A DARK AREA FORWARD OF THE THROTTLE QUADRANT. APCH CTL CONTINUED OUR DSCNT AND VECTORED US TO A FINAL APCH FOR RWY 10R BOI, DSNDING TO 4200'. AT 4200' INBND I DIALED IN THE RWY 10R ILS LOC AND GOT A G/S AURAL WARNING. G/S INDICATOR WAS NOTED FULL DEFLECTION UP (THIS OCCURRED 7-8 MI DME). APCHING THE OM THE G/S INDICATION WAS STILL FULL DEFLECTION UP. AT THAT TIME A MISSED APCH WAS INITIATED. SHORTLY THEREAFTER CONTACT WITH TWR RESULTED IN VERIFICATION THAT THE ILS WAS NORMAL ON THEIR MONITOR. CLRNC WAS RECEIVED TO CLB TO 5000' AND VECTOR TO DOWNWIND. AT 5000' APCH CTL ASKED FOR CONFIRMATION OF ALT. WE RESPONDED 5000'. CTL STATED THEIR READOUT WAS 4200'. I ASKED FOR A CURRENT ALTIMETER SETTING AND CTL RESPONDED WITH 29.48. I STATED THAT THE ALTIMETER SETTING ISSUED OT US FROM SLC WAS 30.48 AND ASKED IF THERE WAS A WARNING FROM HIS EQUIP THAT WE WERE LOW ON OUR LAST APCH. HIS RESPONSE WAS THAT EVERYTHING APPEARED NORMAL. AFTER RESETTING OUR ALTIMETERS TO 29.48 A NORMAL APCH AND LNDG WAS EXECUTED. THE CAUSE OF THIS INCIDENT WAS A WRONG ALTIMETER SETTING ISSUED AND RECEIVED BY ZLC CTLR AND ME. THE RECOMMENDED CORRECTIVE ACTION INVOLVES 2 ACTIONS: 1) COMPANY DSCNT CHKLISTS EXECUTED ON DSCNT PASSING 18000' INCLUDES AN ALTIMETER CHK. THIS CHK SHOULD BE EXPANDED TO INCLUDE A X-CHK OF THE A) WX BRIEFING MESSAGE ALTIMETER, B) ATIS ALTIMETER SETTING, C) CTLING AGENCY ALTIMETER ISSUED ON DSCNT. 2) AT 2500' THE RADIO ALTIMETER CHK SHOULD BE EXPANDED TO INCLUDE A COMPARISON OF THE FIELD ELEVATION AND ACFT ELEVATION. THE DIFFERENT SHOULD BE APPROX 2500', VERIFYING RADIO ALTIMETER READING.. SUPPLEMENTAL INFO FROM ACN 13723: SUBSEQUENT INVESTIGATION BY THE COMPANY HAS CONFIRMED THAT 20.48 WAS ASSIGNED BY THE ZLC CTLR.

Data retrieved from NASA's ASRS site as of July 2007 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.