A B737-300 left pack control failed in full cold causing the crew to become extremely cold. Door ope...

Attributes
ACN	651374
Time
Date	200503
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	msl single value : 35000
Aircraft 1
Controlling Facilities	artcc : zmp.artcc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 360 flight time total : 8800 flight time type : 3000
ASRS Report	651376
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 150 flight time total : 15000 flight time type : 2000
ASRS Report	651872
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : temp control
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Problem Areas	Environmental Factor Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

En route we had a problem with the left air mix valve. Every time we tried to command heat for the cockpit; the valve would go 1/2 way on the indicator and then we received a left duct overheat annunciation. This occurred in both 'automatic' and 'manual' functions of the temperature controller. Cockpit became very cold. In fact; ice was forming on the inside of the main windshield and both the captain and first officer heated side windows. I; in fact; was even towards the sun and still we were icing up. It got to the point that we were both freezing and shivering even though we put on our jackets and winter coats. The captain decided that to warm the cockpit; it would require the opening of the cockpit door. He instructed the flight attendants to put up the cart; and one stand guard at the cart and one stand guard at the cockpit door. We remained in this condition until landing; except the cart was stowed and a flight attendant was placed in the cockpit jumpseat to act as barrier. I can say that I have never been so cold before. It was hard to function in this condition. Opening the door helped and I believe it was the right thing to do.

Original NASA ASRS Text

Title: A B737-300 L PACK CTL FAILED IN FULL COLD CAUSING THE CREW TO BECOME EXTREMELY COLD. DOOR OPENED TO HEAT FLT STATION.

Narrative: ENRTE WE HAD A PROB WITH THE L AIR MIX VALVE. EVERY TIME WE TRIED TO COMMAND HEAT FOR THE COCKPIT; THE VALVE WOULD GO 1/2 WAY ON THE INDICATOR AND THEN WE RECEIVED A L DUCT OVERHEAT ANNUNCIATION. THIS OCCURRED IN BOTH 'AUTO' AND 'MANUAL' FUNCTIONS OF THE TEMP CONTROLLER. COCKPIT BECAME VERY COLD. IN FACT; ICE WAS FORMING ON THE INSIDE OF THE MAIN WINDSHIELD AND BOTH THE CAPT AND FO HEATED SIDE WINDOWS. I; IN FACT; WAS EVEN TOWARDS THE SUN AND STILL WE WERE ICING UP. IT GOT TO THE POINT THAT WE WERE BOTH FREEZING AND SHIVERING EVEN THOUGH WE PUT ON OUR JACKETS AND WINTER COATS. THE CAPT DECIDED THAT TO WARM THE COCKPIT; IT WOULD REQUIRE THE OPENING OF THE COCKPIT DOOR. HE INSTRUCTED THE FLT ATTENDANTS TO PUT UP THE CART; AND ONE STAND GUARD AT THE CART AND ONE STAND GUARD AT THE COCKPIT DOOR. WE REMAINED IN THIS CONDITION UNTIL LNDG; EXCEPT THE CART WAS STOWED AND A FLT ATTENDANT WAS PLACED IN THE COCKPIT JUMPSEAT TO ACT AS BARRIER. I CAN SAY THAT I HAVE NEVER BEEN SO COLD BEFORE. IT WAS HARD TO FUNCTION IN THIS CONDITION. OPENING THE DOOR HELPED AND I BELIEVE IT WAS THE RIGHT THING TO DO.

Data retrieved from NASA's ASRS site as of January 2009 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.

A B737-300 left pack control failed in full cold causing the crew to become extremely cold. Door opened to heat flight station.