ACFT EQUIP PROB. ACFT EQUIP DESIGN.

Narrative

WHILE FLYING AT FL310 USING THE ENG AND WING ANTI-ICE SYS; THE FLOW LIGHT ILLUMINATED AND THE CABIN BEGAN TO CLB AT 500-700 FPM. FOLLOWED PROC IN QUICK REF HANDBOOK BUT NO HELP. PWR WAS INCREASED BUT NO HELP. ENG AND WING ANTI-ICE HAD TO BE TURNED OFF TO MAINTAIN CABIN ALT. DURING RECURRENT TRAINING THIS SUBJECT CAME UP FROM THE EXPERIENCES OF OTHER MD-80 PLTS. THIS TRAINING HELPED ME HANDLE THIS SIT. I FEEL THAT AN OPS BULLETIN SHOULD BE ISSUED CONCERNING THIS PROB AND THE QUICK REF HANDBOOK SHOULD ALSO BE UPDATED FOR THIS PROC. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT THEY WERE IN AND OUT OF THE CLOUDS AND THEY HAD THE ANTI-ICE SYS ON AS A PRECAUTIONARY MEASURE WHEN THE 'FLOW LIGHT' CAME ON. THEY CONFIRMED THE CONDITION BY CHKING THE CABIN RATE OF CLB INDICATOR. THEY DECIDED TO DISCONTINUE ANTI-ICING AT THAT TIME. LATER AT AN INTERMEDIATE LEVELOFF ALT OF 15000 FT; THEY AGAIN PUT ON THE ANTI-ICING SYS AND EVEN AT HIGH THRUST SETTINGS (WITH SPD BRAKES EXTENDED) THE CABIN ALT BEGAN TO CLB FORCING THEM TO DISCONTINUE USING ANTI-ICE. THERE WAS AN ACR INSPECTOR IN THE JUMP SEAT AND HE AND THE FLC DISCUSSED THE SIT AS IT OCCURRED.