A MISSET ALTIMETER ON AN MD90 CAUSES THE ACFT TO BE FLOWN 1000 FT LOW IN THE HOLDING PATTERN.

Narrative

ON THE JANESVILLE 4 ARR TO ORD; AFTER RECEIVING CLRNC TO FL180 TO ENTER HOLDING AT TEDDY AND PROGRAMMING THE FMS; AS THE PNF; I TURNED OVER ATC COM DUTIES TO THE FO WHILE I MADE THE REQUIRED RADIO CALLS TO COMPANY OPS AND GET UPDATED WX. THE FO GOT CLRNC TO DSND TO 16000 FT AND WAS GIVEN AN ALTIMETER SETTING WHICH HE STATED HE READ BACK AS 30.53. (ACTUAL SETTING WAS 29.53.) THE ACFT LEVELED AT 16000 FT ON THE FO ALTIMETER (15000 FT ACTUAL ALT) AS HE MADE A CALL TO ATC RPTING ENTERING HOLDING AT 16000 FT. THE CTLR QUESTIONED THE ALT AND AFTER SOME DISCUSSION BTWN ATC AND THE FO THE ALTIMETER SETTING ERROR WAS DISCOVERED. THE FO STARTED AN IMMEDIATE CLB AND RESET HIS ALTIMETER; SETTING OFF THE ALT WARNING WHICH GOT MY ATTN JUST AS ATC WAS CONFIRMING THAT WE SHOULD CLB BACK TO 16000 FT. IT IS; OF COURSE; ALWAYS PREFERABLE FOR THE PNF TO BACKUP THE PF; BUT IN A 2-MAN COCKPIT; THAT IS JUST NOT ALWAYS POSSIBLE. STILL; EXTRA DILIGENCE IS REQUIRED FROM BOTH PLTS WHEN ONE MUST DIVERT HIS ATTN TO NON FLYING DUTIES. THERE ALSO SEEMS TO BE DEVELOPING AMONG PLTS AND CTLRS A DECREASED ATTN TO ALTIMETER SETTINGS. PLTS SOMETIMES DO NOT RECEIVE AND OFTEN DO NOT READ BACK ALTIMETER SETTINGS AND ERRONEOUS READBACKS ARE OFTEN NOT CHALLENGED. WITH JET ACFT SPENDING VERY LITTLE LEVEL FLT TIME BELOW FL180 AND WITH MOST APCHS ENDING IN A VISUAL APCH; ALTIMETER SETTING ERRORS USUALLY DO NOT RESULT IN SIGNIFICANT OR DANGEROUS ALTDEVS. BUT THERE ARE TIMES WHEN ALTIMETER SETTING ERRORS ARE LARGE ENOUGH TO CAUSE SIGNIFICANT ALTDEVS AND STILL SEEM TO BE SETTINGS IN THE 'REASONABLE RANGE.'