What was found
WHILE AT 28K ALTITUDE, CREW TURNED PACKS ON HIGH (HEAT), AFTER 20MIN RT PACK FAILED INDICATION ILLUMINATED, CREW FOLLOWED QRH. ABOUT A MIN LATER WITH PACKS ON LOW SETTING, CREW STARTED GETTING SMOKE. CREW FOLLOWED QRH FOR SMOKE BUT SMOKE DIDN’T EVAC FAST ENOUGH. CREW DESCENDED TO 10K & EMERGENCY DECLARED BY ATC. BY THE TIME 10K WAS REACHED, SMOKE WAS CLEAR. WHILE ON APPROACH TO KMQY CREW RAN THE PACKS IN LOW & NORMAL WITHOUT INCIDENT. SMOKE WAS MINIMIZED BY SHUTTING OFF PACKS, RECIRC FANS, AND GASPER FANS. SMELL WAS DESCRIBED AS SIMILAR TO WHEN A HOUSES HEATER IS USED FOR THE FIRST TIME. PERFORMED OPS CHECK OF BOTH PACKS IAW MM 21-60-00, NO DISCREPANCIES NOTED. PERFORMED VISUAL INSPECTION OF BOTH PACKS WITH NO DISCREPANCIES NOTED. CONTINUED OPS IAW MEL 21-50-2.