Narrative:

Aircraft was deiced at cmh for frost on wings and fuselage after an overnight layover for an early morning departure. On takeoff and initial climb, there was a slight smell of glycol in cockpit and cabin. Smell disappeared at mid climb and cruise. At 35000 ft power was reduced to idle for descent into stl. Again a slight smell of glycol with a puff of smoke around flight engineer's panel. During descent, smell again disappeared, all cockpit indications were normal. At XA34 local time, just past petti intersection at 11000 ft, 250 KTS, clearance to 4000 ft was received. Power reduced to idle for descent. At this time, glycol smell returned and cockpit and cabin began to fill with smoke. I declared an emergency to stl approach, closed down left air conditioning pack, and applied power to all engines while on descent. We proceeded direct to stl airport at 290 KTS below 10000 ft and landed 7 mins later. Halfway to airport smoke and smell began to abate. Landing and taxi in was smoke and smell free. I believe aircraft was improperly deiced on ground at cmh in that glycol was sprayed into every opening. Glycol must have been pocketed in air conditioning units so that when deck angle lowered, and 13TH stage air came on at idle, and air cycle machine began to operate, aircraft began to fill with smoke. It takes only a small amount of glycol to produce smoke.

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Original NASA ASRS Text

Title: EMER DECLARED AS SMOKE FROM GLYCOL ENTERS COCKPIT AND CABIN.

Narrative: ACFT WAS DEICED AT CMH FOR FROST ON WINGS AND FUSELAGE AFTER AN OVERNIGHT LAYOVER FOR AN EARLY MORNING DEP. ON TKOF AND INITIAL CLB, THERE WAS A SLIGHT SMELL OF GLYCOL IN COCKPIT AND CABIN. SMELL DISAPPEARED AT MID CLB AND CRUISE. AT 35000 FT PWR WAS REDUCED TO IDLE FOR DSCNT INTO STL. AGAIN A SLIGHT SMELL OF GLYCOL WITH A PUFF OF SMOKE AROUND FE'S PANEL. DURING DSCNT, SMELL AGAIN DISAPPEARED, ALL COCKPIT INDICATIONS WERE NORMAL. AT XA34 LCL TIME, JUST PAST PETTI INTXN AT 11000 FT, 250 KTS, CLRNC TO 4000 FT WAS RECEIVED. PWR REDUCED TO IDLE FOR DSCNT. AT THIS TIME, GLYCOL SMELL RETURNED AND COCKPIT AND CABIN BEGAN TO FILL WITH SMOKE. I DECLARED AN EMER TO STL APCH, CLOSED DOWN L AIR CONDITIONING PACK, AND APPLIED PWR TO ALL ENGS WHILE ON DSCNT. WE PROCEEDED DIRECT TO STL ARPT AT 290 KTS BELOW 10000 FT AND LANDED 7 MINS LATER. HALFWAY TO ARPT SMOKE AND SMELL BEGAN TO ABATE. LNDG AND TAXI IN WAS SMOKE AND SMELL FREE. I BELIEVE ACFT WAS IMPROPERLY DEICED ON GND AT CMH IN THAT GLYCOL WAS SPRAYED INTO EVERY OPENING. GLYCOL MUST HAVE BEEN POCKETED IN AIR CONDITIONING UNITS SO THAT WHEN DECK ANGLE LOWERED, AND 13TH STAGE AIR CAME ON AT IDLE, AND AIR CYCLE MACHINE BEGAN TO OPERATE, ACFT BEGAN TO FILL WITH SMOKE. IT TAKES ONLY A SMALL AMOUNT OF GLYCOL TO PRODUCE SMOKE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.