Narrative:

Conditions at our time of departure were continuous moderate snow. Exterior and cockpit preflight preparations were normal as we waited for fueling and deicing operations to finish. We received our deicing briefing and had a normal pushback. All 3 engine starts were normal and we completed our 'before taxi' checklist. On taxi, the air-conditioning cooling doors were closed in accordance with taxi operations in snow and slush. All taxi and takeoff checklist items were completed. I performed a visual inspection of the wings and they proved to be free of snow and ice. Returning to my seat, the captain gave us a full takeoff briefing for his leg. We received our takeoff clearance and 'takeoff final items' checklist was completed. Acceleration and takeoff were normal. On initial climb out I noticed a rapid increase in the environmental duct temperature along with an increasing temperature in the #2 pack. I attempted to adjust the temperature controls but it had no effect. I informed the captain and he recommended to turn off pack #2 and I agreed. I referred to the communication to work the problem with the first officer. Quickly following, the #1 pack temperature began to show an overheat which could not be controled. I informed the captain and he stated that it needed to be turned off. I agreed. We informed ATC that we would not be able to pressurize and needed a leveloff. I continued to work through the communication with the first officer and it was determined that we would not be able to use the packs. We placed a phone patch to our company dispatch and they recommended a return to our departure airport. All communication procedures were completed and we informed our cabin crew and passenger of our return. We informed ATC we would be returning and that we required a short amount of time to dump fuel to help us make our landing weight. The fuel dumping procedure was completed by the checklist at which time we flew an ILS to a normal approach and landing. Upon return to the gate, a maintenance inspection revealed that the ram air cooling inlet had ingested snow and no cooling was available.

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Original NASA ASRS Text

Title: AN ACR B727-200 FLC HAS BOTH AIR-CONDITIONING PACKS OVERHEAT AFTER TKOF FROM AN ARPT IN MODERATE SNOW CONDITIONS.

Narrative: CONDITIONS AT OUR TIME OF DEP WERE CONTINUOUS MODERATE SNOW. EXTERIOR AND COCKPIT PREFLT PREPARATIONS WERE NORMAL AS WE WAITED FOR FUELING AND DEICING OPS TO FINISH. WE RECEIVED OUR DEICING BRIEFING AND HAD A NORMAL PUSHBACK. ALL 3 ENG STARTS WERE NORMAL AND WE COMPLETED OUR 'BEFORE TAXI' CHKLIST. ON TAXI, THE AIR-CONDITIONING COOLING DOORS WERE CLOSED IN ACCORDANCE WITH TAXI OPS IN SNOW AND SLUSH. ALL TAXI AND TKOF CHKLIST ITEMS WERE COMPLETED. I PERFORMED A VISUAL INSPECTION OF THE WINGS AND THEY PROVED TO BE FREE OF SNOW AND ICE. RETURNING TO MY SEAT, THE CAPT GAVE US A FULL TKOF BRIEFING FOR HIS LEG. WE RECEIVED OUR TKOF CLRNC AND 'TKOF FINAL ITEMS' CHKLIST WAS COMPLETED. ACCELERATION AND TKOF WERE NORMAL. ON INITIAL CLBOUT I NOTICED A RAPID INCREASE IN THE ENVIRONMENTAL DUCT TEMP ALONG WITH AN INCREASING TEMP IN THE #2 PACK. I ATTEMPTED TO ADJUST THE TEMP CTLS BUT IT HAD NO EFFECT. I INFORMED THE CAPT AND HE RECOMMENDED TO TURN OFF PACK #2 AND I AGREED. I REFERRED TO THE COM TO WORK THE PROB WITH THE FO. QUICKLY FOLLOWING, THE #1 PACK TEMP BEGAN TO SHOW AN OVERHEAT WHICH COULD NOT BE CTLED. I INFORMED THE CAPT AND HE STATED THAT IT NEEDED TO BE TURNED OFF. I AGREED. WE INFORMED ATC THAT WE WOULD NOT BE ABLE TO PRESSURIZE AND NEEDED A LEVELOFF. I CONTINUED TO WORK THROUGH THE COM WITH THE FO AND IT WAS DETERMINED THAT WE WOULD NOT BE ABLE TO USE THE PACKS. WE PLACED A PHONE PATCH TO OUR COMPANY DISPATCH AND THEY RECOMMENDED A RETURN TO OUR DEP ARPT. ALL COM PROCS WERE COMPLETED AND WE INFORMED OUR CABIN CREW AND PAX OF OUR RETURN. WE INFORMED ATC WE WOULD BE RETURNING AND THAT WE REQUIRED A SHORT AMOUNT OF TIME TO DUMP FUEL TO HELP US MAKE OUR LNDG WT. THE FUEL DUMPING PROC WAS COMPLETED BY THE CHKLIST AT WHICH TIME WE FLEW AN ILS TO A NORMAL APCH AND LNDG. UPON RETURN TO THE GATE, A MAINT INSPECTION REVEALED THAT THE RAM AIR COOLING INLET HAD INGESTED SNOW AND NO COOLING WAS AVAILABLE.

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.