A B737-200 in climb at 14000 ft had cabin pressure warning horn and cabin pressure above 10000 ft wi...

Attributes
ACN	512861
Time
Date	200105
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : buf.vortac
State Reference	NY
Altitude	msl single value : 14000
Environment
Flight Conditions	IMC
Weather Elements	Rain
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc tower : rno.tower
Operator	common carrier : air carrier
Make Model Name	B737-200
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Route In Use	departure : on vectors
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : cfi pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 228 flight time total : 10095 flight time type : 528
ASRS Report	512861
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : cabin altitude indicator other flight crewa other flight crewb
Resolutory Action	flight crew : diverted to another airport flight crew : overcame equipment problem
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft Environmental Factor
Primary Problem	Flight Crew Human Performance

Narrative:

Started engine #2, configured the bleed air control panel for maximum heating and single engine taxi (right pack on, pneumatic isolation valve closed, left pack on). Taxied to runway 23 for departure and held in the holding area. Approaching wheels-up time, started #1 engine. After #1 engine started, I positioned the pneumatic isolation valve to 'automatic' and moved a pack switch (I believed I had moved the left pack switch to the 'on' position). Started on the delayed engine start checklist. Interrupted by a takeoff clearance from tower, I responded and continued with the delayed engine start checklist. We started to taxi into position for takeoff, read and performed the before takeoff checklist. Each time I reached the line on the delayed engine start and the before takeoff checklist concerning the air conditioning and pressure, I looked at the bleed air panel and was convinced I saw the left and right pack switches in the 'on' position. I, as the PF, performed a normal takeoff and climb out. When the cabin reached approximately 10000 ft, the cabin altitude horn sounded. The aircraft did not pressurize. We were slow to recognize this situation. The PNF began troubleshooting and found the pack switches in the 'off' position. Realizing the cabin was above 10000 ft, we immediately donned our masks. The PNF placed the pack switches to the 'on' position and I leveled the aircraft at approximately 14000 ft. The cabin started to pressurize but the cabin masks had already deployed. At this point, we decided to return to the buffalo airport. We made an uneventful return, approach and landing at buf.

Original NASA ASRS Text

Title: A B737-200 IN CLB AT 14000 FT HAD CABIN PRESSURE WARNING HORN AND CABIN PRESSURE ABOVE 10000 FT WITH CABIN MASKS DEPLOYED. CAUSED BY FAILURE TO SWITCH L AND R PACKS TO ON POS.

Narrative: STARTED ENG #2, CONFIGURED THE BLEED AIR CTL PANEL FOR MAX HEATING AND SINGLE ENG TAXI (R PACK ON, PNEUMATIC ISOLATION VALVE CLOSED, L PACK ON). TAXIED TO RWY 23 FOR DEP AND HELD IN THE HOLDING AREA. APCHING WHEELS-UP TIME, STARTED #1 ENG. AFTER #1 ENG STARTED, I POSITIONED THE PNEUMATIC ISOLATION VALVE TO 'AUTO' AND MOVED A PACK SWITCH (I BELIEVED I HAD MOVED THE L PACK SWITCH TO THE 'ON' POS). STARTED ON THE DELAYED ENG START CHKLIST. INTERRUPTED BY A TKOF CLRNC FROM TWR, I RESPONDED AND CONTINUED WITH THE DELAYED ENG START CHKLIST. WE STARTED TO TAXI INTO POS FOR TKOF, READ AND PERFORMED THE BEFORE TKOF CHKLIST. EACH TIME I REACHED THE LINE ON THE DELAYED ENG START AND THE BEFORE TKOF CHKLIST CONCERNING THE AIR CONDITIONING AND PRESSURE, I LOOKED AT THE BLEED AIR PANEL AND WAS CONVINCED I SAW THE L AND R PACK SWITCHES IN THE 'ON' POS. I, AS THE PF, PERFORMED A NORMAL TKOF AND CLBOUT. WHEN THE CABIN REACHED APPROX 10000 FT, THE CABIN ALT HORN SOUNDED. THE ACFT DID NOT PRESSURIZE. WE WERE SLOW TO RECOGNIZE THIS SIT. THE PNF BEGAN TROUBLESHOOTING AND FOUND THE PACK SWITCHES IN THE 'OFF' POS. REALIZING THE CABIN WAS ABOVE 10000 FT, WE IMMEDIATELY DONNED OUR MASKS. THE PNF PLACED THE PACK SWITCHES TO THE 'ON' POS AND I LEVELED THE ACFT AT APPROX 14000 FT. THE CABIN STARTED TO PRESSURIZE BUT THE CABIN MASKS HAD ALREADY DEPLOYED. AT THIS POINT, WE DECIDED TO RETURN TO THE BUFFALO ARPT. WE MADE AN UNEVENTFUL RETURN, APCH AND LNDG AT BUF.

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.

A B737-200 in climb at 14000 ft had cabin pressure warning horn and cabin pressure above 10000 ft with cabin masks deployed. Caused by failure to switch left and right packs to on position.