A COMMERCIAL FIXED WING ACFT IN CLB SWITCHED AIRFOIL DEICING TO ON AND GOT AIRFOIL DUCT FAILURE WARNING. DIVERTED DUE TO DOWNLINE WX.

Narrative

ON CLBOUT FROM LAS; WE PASSED THROUGH AN AREA OF SUSPECTED ICING. THE ICE DETECTION LIGHT ILLUMINATED. WE TURNED ON THE WING AND ENG ANTI-ICE. WE IMMEDIATELY GOT A R PNEUMATIC DUCT LEAK LIGHT ON THE OVERHEAD PNEUMATIC PANEL. THIS WAS ACCOMPANIED BY WARNING/CAUTION MESSAGES ON EICAS: R WING AND ENG ANTI-ICE ALONG WITH DUCT LEAK MESSAGE. THE ABNORMAL PROC WAS ACCOMPLISHED; AFTER THE BLEED AIR WAS REMOVED FROM THE R PNEUMATIC SYS; THE DUCT LEAK EXTINGUISHED. THE ABNORMAL PROC ISSUED THE DIRECTIVE TO AVOID KNOWN; FORECAST OR POSSIBLE ICING. WE ACCOMPLISHED AN ENRTE DIVERSION TO XYZ; AZ; RATHER THAN CONTINUE ON TO XYA TO AVOID ANY POSSIBLE ICING CONDITIONS. WE REQUESTED AN APCH TO RWY 26 IN XYZ TO OBTAIN THE LONGEST USABLE RWY SINCE WE WOULD BE MAKING A HVY OVERWT LNDG. BECAUSE OF ALL THE DISTRS CONCERNING THE ABNORMAL PROC AND DIVERT PROC; WE DID NOT NOTICE THAT RWY 26 WAS CUT BACK DUE TO CONSTRUCTION AND ONLY HAD 6000 FT AVAILABLE. OUR FIRST INDICATION THAT WE WERE NOT GETTING WHAT WE EXPECTED WAS WHEN WE COULDN'T BRING UP THE ILS RWY 26. THEN; VISUALLY; I WAS ABLE TO SEE THE CONSTRUCTION FOR RWY 26. THIS OVERSIGHT WAS NOT CRITICAL SINCE WE WERE VFR AND COULD SEE THE RWY; BUT IF WE HAD BEEN IFR AND DISCOVERED OUR OVERSIGHT AT 200 FT AGL; IT WOULD HAVE BEEN VERY SERIOUSLY. THE LESSON TO LEARN: IT IS ESPECIALLY IMPORTANT UNDER ABNORMAL PROCS TO REMEMBER TO ACCOMPLISH ALL THE NORMAL PROCS LIKE REVIEWING THE NOTAMS. AN UNEVENTFUL LNDG ON RWY 25R WAS ACCOMPLISHED. AT THE GATE; MAINT DISCOVERED THAT OUR PNEUMATIC R WING MANIFOLD DUCTING HAD A LEAK; WHICH WAS THE CAUSE OF OUR ABNORMAL INDICATIONS.