B737-700 flight crew utilizes an incorrect altimeter setting on descent.

Attributes
ACN	801299
Time
Date	200808
Place
Locale Reference	airport : bwi.airport
State Reference	MD
Altitude	agl single value : 16000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : pdx.tower
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 152 flight time type : 25000
ASRS Report	801299
Events
Anomaly	altitude deviation : crossing restriction not met non adherence : published procedure
Independent Detector	other flight crewb
Resolutory Action	flight crew : became reoriented
Supplementary
Problem Areas	Flight Crew Human Performance Environmental Factor Aircraft
Primary Problem	Flight Crew Human Performance

Narrative:

We prepared for the descent by obtaining the d-atis (digital ATIS); consulting the performance information; and completing the arrival briefing prior to descent. During the approach; the first officer noticed a discrepancy between the RA altitudes and the altimeter readings and requested the current altimeter from tower. We had set 30.04 passing FL180 which was transcribed on the napkin. The altimeter that tower gave was 30.33. At the gate; I checked the d-atis that we had referenced in the FMC and it read 30.34. The first officer had written the incorrect altimeter setting on the napkin and my brief was based on that number. The RNAV arrival was flown precisely but with the incorrect altimeter setting from FL180 and below. The sacco; fimbo; udude; rexee; ott; and ravnn crossing restrs would have been affected. I can correct this type of error in the future by pulling up the d-atis on the FMC as I do the descent checklist; but we are usually active in the descent so the descent page is being utilized. There were no updates issued by approach nor was an altimeter given when we were assigned to descend via the RAVNN2 arrival as we checked in with the d-atis from bwi. A quick button to pull up the d-atis in the FMC would allow crew members to reference the arrival information directly to circumvent transcription errors without having to go through 3-4 pages to access the data as is required now.

Original NASA ASRS Text

Title: B737-700 FLT CREW UTILIZES AN INCORRECT ALTIMETER SETTING ON DESCENT.

Narrative: WE PREPARED FOR THE DSCNT BY OBTAINING THE D-ATIS (DIGITAL ATIS); CONSULTING THE PERFORMANCE INFO; AND COMPLETING THE ARR BRIEFING PRIOR TO DSCNT. DURING THE APCH; THE FO NOTICED A DISCREPANCY BTWN THE RA ALTS AND THE ALTIMETER READINGS AND REQUESTED THE CURRENT ALTIMETER FROM TWR. WE HAD SET 30.04 PASSING FL180 WHICH WAS TRANSCRIBED ON THE NAPKIN. THE ALTIMETER THAT TWR GAVE WAS 30.33. AT THE GATE; I CHKED THE D-ATIS THAT WE HAD REFED IN THE FMC AND IT READ 30.34. THE FO HAD WRITTEN THE INCORRECT ALTIMETER SETTING ON THE NAPKIN AND MY BRIEF WAS BASED ON THAT NUMBER. THE RNAV ARR WAS FLOWN PRECISELY BUT WITH THE INCORRECT ALTIMETER SETTING FROM FL180 AND BELOW. THE SACCO; FIMBO; UDUDE; REXEE; OTT; AND RAVNN XING RESTRS WOULD HAVE BEEN AFFECTED. I CAN CORRECT THIS TYPE OF ERROR IN THE FUTURE BY PULLING UP THE D-ATIS ON THE FMC AS I DO THE DSCNT CHKLIST; BUT WE ARE USUALLY ACTIVE IN THE DSCNT SO THE DSCNT PAGE IS BEING UTILIZED. THERE WERE NO UPDATES ISSUED BY APCH NOR WAS AN ALTIMETER GIVEN WHEN WE WERE ASSIGNED TO DSND VIA THE RAVNN2 ARR AS WE CHKED IN WITH THE D-ATIS FROM BWI. A QUICK BUTTON TO PULL UP THE D-ATIS IN THE FMC WOULD ALLOW CREW MEMBERS TO REF THE ARR INFO DIRECTLY TO CIRCUMVENT TRANSCRIPTION ERRORS WITHOUT HAVING TO GO THROUGH 3-4 PAGES TO ACCESS THE DATA AS IS REQUIRED NOW.

Data retrieved from NASA's ASRS site as of May 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.