ACR CREW FAILS TO ENGAGE PROPER MODE AFTER ALTIMETER RESET BELOW FL180.

Narrative

WHEN DSNDING BELOW FL180; MY ALTIMETER WAS SET TO THE PROPER BAROMETRIC PRESSURE; BUT DUE TO ADVANCED COCKPIT DESIGN; THE PUSH BUTTON WHICH CTLS THE ALTIMETER DISPLAY WAS INADVERTENTLY LEFT IN 'STD'. AS A RESULT; 29.92 WAS THE ACTIVE SETTING WHEN LEVELING AT 10000 FT. THIS RESULTED IN A LEVEL OFF 200-300 FT HIGH. THE SITUATION WAS RECOGNIZED WHEN THE BEFORE LNDG CHKLIST WAS COMPLETED. 2 FACTORS LED TO THIS PROBLEM. COCKPIT DESIGN WHICH REQUIRES CREW TO SET THE PROPER BAROMETRIC PRESSURE AND ALSO REQUIRES THAT A PUSH BUTTON BE SELECTED IN THE PROPER MODE. THE 2 MODES AVAILABLE ARE 'STD' WHICH IS USED AT AND ABOVE FL180 AND 'QNH' WHICH SETS THE ALTIMETER TO THE PRESSURE SET BY THE CREW. THE SECOND FACTOR IS THAT OUR PROC IS TO MAINTAIN A STERILE COCKPIT AND PERFORM THE BEFORE LNDG CHKLIST AT APPROX 10000 FT. THIS MEANS THAT THE CREW'S ATTN MAY BE DIVERTED BTWN FL180 AND 10000 FT. IN ADDITION; DELAYING THE CHKLIST MEANS THAT CHKING FOR PROPER MODES IS NOT ACCOMPLISHED UNTIL REACHING 10000 FT. AS A RESULT; I WILL START MAINTAINING A STERILE COCKPIT AND ACCOMPLISH THE CHKLIST AT FL180 INSTEAD OF 10000 FT. YOU CAN NEVER BE TOO EARLY!