Narrative:

I was the pilot flying. On approach into the airport we were given a crossing restriction of 14;000 ft. Upon passing 18;000 ft in our descent we ran the descent and approach checklist. The captain and I both confirmed the altimeter settings were 30.12. As we approached the fix the altitude alerter sounded a thousand feet off of the captain's side. At the fix we were given 12;000 ft and the captain made a comment that the altitude did not capture. As I continued to descend the captain instructed me to watch the autopilot and at 12;000 ft on his altimeter the airplane continued to descend. He instructed me to stop the airplane. I turned off the autopilot and hand flew it while we assessed the problem. I then transferred control to the captain. I noticed my altimeter was reading 31.12. I adjusted my altimeter to the correct setting. ATC assigned us 11;000 ft about this time. I took back control of the aircraft after confirmation of the new altitude was received from ATC by the captain. The captain advised the controller of a mishap and we continued the flight with no further instances. I feel that perhaps complacency was a factor. My habit of spinning the barometer setting knob instead of slowly turning it perhaps allowed the setting to jump so drastically. Normally the knob is hard to turn and the numbers change more slowly. Careful attention to all four numbers during the checklist rather than the final two could have prevented this error. Careful attention must be made each and every time a checklist is run regardless of the how many numerous of times it has been run in the past.I feel that more careful attention to all details of the checklist in the future will benefit me greatly. Double checking myself and the computer is a must to ensure safety and compliance. Taking my time and being more deliberate and diligent with the details of the checklist can prevent future mishaps. I also feel that stopping the airplane manually and overriding it more quickly before the automation is allowed to deviate from a clearance or when some information is in question. If something seems off chances are it is.

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Original NASA ASRS Text

Title: An air carrier First Officer had a habit of setting his altimeter's barometric pressure by 'spinning' the set knob but inadvertently set a 1.00 difference causing an altitude deviation because the autopilot did not capture the MCP altitude.

Narrative: I was the pilot flying. On approach into the airport we were given a crossing restriction of 14;000 FT. Upon passing 18;000 FT in our descent we ran the descent and approach checklist. The Captain and I both confirmed the altimeter settings were 30.12. As we approached the fix the altitude alerter sounded a thousand feet off of the Captain's side. At the fix we were given 12;000 FT and the Captain made a comment that the altitude did not capture. As I continued to descend the Captain instructed me to watch the autopilot and at 12;000 FT on his altimeter the airplane continued to descend. He instructed me to stop the airplane. I turned off the autopilot and hand flew it while we assessed the problem. I then transferred control to the Captain. I noticed my altimeter was reading 31.12. I adjusted my altimeter to the correct setting. ATC assigned us 11;000 FT about this time. I took back control of the aircraft after confirmation of the new altitude was received from ATC by the Captain. The Captain advised the Controller of a mishap and we continued the flight with no further instances. I feel that perhaps complacency was a factor. My habit of spinning the barometer setting knob instead of slowly turning it perhaps allowed the setting to jump so drastically. Normally the knob is hard to turn and the numbers change more slowly. Careful attention to all four numbers during the checklist rather than the final two could have prevented this error. Careful attention must be made each and every time a checklist is run regardless of the how many numerous of times it has been run in the past.I feel that more careful attention to all details of the checklist in the future will benefit me greatly. Double checking myself and the computer is a must to ensure safety and compliance. Taking my time and being more deliberate and diligent with the details of the checklist can prevent future mishaps. I also feel that stopping the airplane manually and overriding it more quickly before the automation is allowed to deviate from a clearance or when some information is in question. If something seems off chances are it is.

Data retrieved from NASA's ASRS site as of July 2013 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.