ACFT ENTERED AN AREA OF FCST MOD ICING. ICE DETECTION SYS HAD BEEN INTRMTLY INOP. THE ACFT ENTERED HOLDING IN ICING COND WHILE CKG FLT INSP EQUIP. EVIDENCE INDICATED CREW NOTED ICE ACCRETION, ACTIVATED SURFACE DE-ICE SYS, ICE BROKE LOOSE AND ENTERED ENG INTAKES. BOTH ENGS FLAMED OUT. DRG EMERG DESCENT CREW INIT RE-STARTS, BUT NEITHER ENG WOULD SUSTAIN PWR. CREW RQSTD VECTORS TO MORE DISTANT AIRPORT. BOTH PLTS WERE SEEN DRINKING PREV NIGHT. C/P HAD RECENTLY LOST DRIVERS LICENSE FOR DUI. CAPT HAD DECIDED TO RETIRE THAT DAY. C/P HAD WORKED IN FLT OPS 3 DAYS IN 8 WKS AND HAD LMTD TRNG IN FLT INSPECTION. BOTH PLTS HAD PERSONAL STRESSES WHICH MAY HAVE INFLUENCED PERFORMANCE. CAPT'S CONTAMINATED THORACIC BLOOD REVEALED 0.057% ALCOHOL. PUTRIFICATION WOULD ACCT FOR PART OF ALCOHOL LEVEL. C/P HAD TRACE ALCOHOL IN URINE ONLY. BOTH ENGS SHOWED COMPRESSOR FOD CONSISTENT WITH ICE INGESTION. NO OTHER ACFT SYS OR ENG MALFUNCTION FOUND.