What was found
IN CRUISE, PILOT NOTICED BURNING SMELL AND HAZE IN COCKPIT. HAZE WAS NOT VISIBLE IN CABIN. PILOT TURNED OFF PACK NR 2 AND SMELL AND HAZE DISSAPATED. NR 2 PACK PRESSURE PEGGED AT 5.0. MX RAN ENGINES AT SEVERAL POWER SETTINGS AND COULD NOT DUPLICATE. ENGINE BLEED AND A/C PACK OPERATION CHECKS GOOD. PERFORMED OPN 5088 AND NO TROUBLE WAS FOUND. PERFORMED A DUCT BURNOUT OPN 5089 AS PRECAUTIONARY. PNEUMATIC BLEED SYS AND A/C PACK SYS OPS CHECK GOOD.