B737-500 flight crew both set incorrect altimeter setting when climbing through transition altitude.

Attributes
ACN	768493
Time
Date	200801
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sea.airport
State Reference	WA
Altitude	msl single value : 31700
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	artcc : zse.artcc
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Flight Phase	climbout : vacating altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 252 flight time type : 490
ASRS Report	768493
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued alert flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

We departed sea where the altimeter was unusually low (28.83). Neither the captain nor I ever recalled flying in such a low altimeter setting. This led to us incorrectly setting 28.92 as we climbed through 18000 ft. Both of us did the same thing and we did not notice the mistake until ZSE asked about our altitude we were cleared to and then if we were using 29.92. We exceeded our cleared to altitude (FL310) by 700 ft when the captain started a correction. We asked if we had created any conflicts and ZSE said no. If I ever see such a low altimeter again; I will be very careful in any altimeter changes; especially when flying a classic aircraft.

Original NASA ASRS Text

Title: B737-500 FLT CREW BOTH SET INCORRECT ALTIMETER SETTING WHEN CLIMBING THROUGH TRANSITION ALTITUDE.

Narrative: WE DEPARTED SEA WHERE THE ALTIMETER WAS UNUSUALLY LOW (28.83). NEITHER THE CAPT NOR I EVER RECALLED FLYING IN SUCH A LOW ALTIMETER SETTING. THIS LED TO US INCORRECTLY SETTING 28.92 AS WE CLBED THROUGH 18000 FT. BOTH OF US DID THE SAME THING AND WE DID NOT NOTICE THE MISTAKE UNTIL ZSE ASKED ABOUT OUR ALT WE WERE CLRED TO AND THEN IF WE WERE USING 29.92. WE EXCEEDED OUR CLRED TO ALT (FL310) BY 700 FT WHEN THE CAPT STARTED A CORRECTION. WE ASKED IF WE HAD CREATED ANY CONFLICTS AND ZSE SAID NO. IF I EVER SEE SUCH A LOW ALTIMETER AGAIN; I WILL BE VERY CAREFUL IN ANY ALTIMETER CHANGES; ESPECIALLY WHEN FLYING A CLASSIC ACFT.

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.