Narrative:

Climbing through 10000 ft, the first officer called for economy climb speed. I attempted to execute his request, but the speed line on the climb page went blank. We then noticed a significant difference between the captain's and first officer's airspeed indicators (approximately 50 KIAS) and altimeters (approximately 2000 ft). We contacted ATC and requested a block altitude while we sorted through the problem. We determined that the captain's instruments matched the standby instruments. Upon reaching cruise altitude according to the captain's instrument, we noted that the pressurization system indicated the correct cabin altitude and differential. We contacted dispatch and maintenance. We concluded that the first officer's instruments were incorrect and that we still had 2 independent sources of correct airspeed and altitude information. We also concurred that the flight could continue on to ord safely. There were no flags or warnings on any of the airspeed indicators or altimeters. All other navigation and attitude instruments were normal. I assumed the duties of PF, and the flight continued to ord without further incident. There was a great deal of dialogue between the first officer and myself. He asked a number of pertinent questions and helped insure that we covered all the bases. ATC was very supportive while we determined which instruments were correct. Dispatch and maintenance were also great resources.

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Original NASA ASRS Text

Title: B737-300 CREW HAD LARGE DIFFERENCES BTWN THE CAPT AND FO IAS AND ALTIMETER.

Narrative: CLBING THROUGH 10000 FT, THE FO CALLED FOR ECONOMY CLB SPD. I ATTEMPTED TO EXECUTE HIS REQUEST, BUT THE SPD LINE ON THE CLB PAGE WENT BLANK. WE THEN NOTICED A SIGNIFICANT DIFFERENCE BTWN THE CAPT'S AND FO'S AIRSPD INDICATORS (APPROX 50 KIAS) AND ALTIMETERS (APPROX 2000 FT). WE CONTACTED ATC AND REQUESTED A BLOCK ALT WHILE WE SORTED THROUGH THE PROB. WE DETERMINED THAT THE CAPT'S INSTS MATCHED THE STANDBY INSTS. UPON REACHING CRUISE ALT ACCORDING TO THE CAPT'S INST, WE NOTED THAT THE PRESSURIZATION SYS INDICATED THE CORRECT CABIN ALT AND DIFFERENTIAL. WE CONTACTED DISPATCH AND MAINT. WE CONCLUDED THAT THE FO'S INSTS WERE INCORRECT AND THAT WE STILL HAD 2 INDEPENDENT SOURCES OF CORRECT AIRSPD AND ALT INFO. WE ALSO CONCURRED THAT THE FLT COULD CONTINUE ON TO ORD SAFELY. THERE WERE NO FLAGS OR WARNINGS ON ANY OF THE AIRSPD INDICATORS OR ALTIMETERS. ALL OTHER NAV AND ATTITUDE INSTS WERE NORMAL. I ASSUMED THE DUTIES OF PF, AND THE FLT CONTINUED TO ORD WITHOUT FURTHER INCIDENT. THERE WAS A GREAT DEAL OF DIALOGUE BTWN THE FO AND MYSELF. HE ASKED A NUMBER OF PERTINENT QUESTIONS AND HELPED INSURE THAT WE COVERED ALL THE BASES. ATC WAS VERY SUPPORTIVE WHILE WE DETERMINED WHICH INSTS WERE CORRECT. DISPATCH AND MAINT WERE ALSO GREAT RESOURCES.

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.