B737-400 flight crew takeoff with pressurization controller in the manual position instead of automatic. During climb, the aircraft didn't pressurize and cabin altitude warning horn sounded.

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Attributes
ACN	569650
Time
Date	200212
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : zzz.vor
State Reference	US
Altitude	msl single value : 31500
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B737-400
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 60 flight time total : 10000 flight time type : 4000
ASRS Report	569650
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe non adherence : company policies non adherence : published procedure
Independent Detector	aircraft equipment : altitude alert aircraft equipment other aircraft equipment : cabin ah warning horn other flight crewa other flight crewb
Resolutory Action	flight crew : overcame equipment problem other
Supplementary
Problem Areas	Flight Crew Human Performance Maintenance Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

First officer did preflight at night. The pressurization controller had been in manual (AC or dc). It is supposed to be in 'automatic.' we took off from ZZZ, after deicing on the ground in ZZZ, the pressurization controller was still in 'manual.' at FL315, the cabin altitude warning horn sounded. Cabin altitude was at 10000 ft. The captain immediately turned the pressurization controller to 'automatic.' the cabin stabilized at 10000 ft, and then started descending to 6400 ft (for FL330). Pressurization was normal for rest of flight (approximately 7 hours). Notified maintenance. No maintenance required. Cabin altitude was at 10000 ft for approximately 1-2 mins. Contributing factors: controller is always left in 'automatic' by flight crew's. Maintenance, possibly turns pressurization to 'manual' to close outflow valve in cold WX. Dark cockpit (night) not familiar with pressurization controls. Discovery and corrective actions: cabin altitude warning horn (10000 ft). Turning pressurization controller to 'automatic.'

Original NASA ASRS Text

Title: B737-400 FLC TKOF WITH PRESSURIZATION CTLR IN THE MANUAL POS INSTEAD OF AUTO. DURING CLB, THE ACFT DIDN'T PRESSURIZE AND CABIN ALT WARNING HORN SOUNDED.

Narrative: FO DID PREFLT AT NIGHT. THE PRESSURIZATION CONTROLLER HAD BEEN IN MANUAL (AC OR DC). IT IS SUPPOSED TO BE IN 'AUTO.' WE TOOK OFF FROM ZZZ, AFTER DEICING ON THE GND IN ZZZ, THE PRESSURIZATION CONTROLLER WAS STILL IN 'MANUAL.' AT FL315, THE CABIN ALT WARNING HORN SOUNDED. CABIN ALT WAS AT 10000 FT. THE CAPT IMMEDIATELY TURNED THE PRESSURIZATION CONTROLLER TO 'AUTO.' THE CABIN STABILIZED AT 10000 FT, AND THEN STARTED DSNDING TO 6400 FT (FOR FL330). PRESSURIZATION WAS NORMAL FOR REST OF FLT (APPROX 7 HRS). NOTIFIED MAINT. NO MAINT REQUIRED. CABIN ALT WAS AT 10000 FT FOR APPROX 1-2 MINS. CONTRIBUTING FACTORS: CTLR IS ALWAYS LEFT IN 'AUTO' BY FLC'S. MAINT, POSSIBLY TURNS PRESSURIZATION TO 'MANUAL' TO CLOSE OUTFLOW VALVE IN COLD WX. DARK COCKPIT (NIGHT) NOT FAMILIAR WITH PRESSURIZATION CTLS. DISCOVERY AND CORRECTIVE ACTIONS: CABIN ALT WARNING HORN (10000 FT). TURNING PRESSURIZATION CTLR TO 'AUTO.'

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.