Narrative:

After extended time at 17000 ft, first officer went to bathroom. As he was exiting the cockpit, center gave us a climb to FL280. Upon level at FL350 for 4 mins, center advised us that we were 400 ft high. The altimeter was set at 29.55. We corrected the error.

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Original NASA ASRS Text

Title: A FOKKER 100 ON CLBING FROM 17000 FT TO FL350 THE CTR ADVISED ACFT WAS AT FL354 DUE TO FAILURE TO SET ALTIMETER TO 29 PT 92.

Narrative: AFTER EXTENDED TIME AT 17000 FT, FO WENT TO BATHROOM. AS HE WAS EXITING THE COCKPIT, CTR GAVE US A CLB TO FL280. UPON LEVEL AT FL350 FOR 4 MINS, CTR ADVISED US THAT WE WERE 400 FT HIGH. THE ALTIMETER WAS SET AT 29.55. WE CORRECTED THE ERROR.

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.