Cabin altitude warning horn alerts flight crew that cabin altitude is above 10000'.

Attributes
ACN	147796
Time
Date	199005
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : dsm
State Reference	IA
Altitude	msl bound lower : 35000 msl bound upper : 35000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 100 flight time total : 2500 flight time type : 350
ASRS Report	147796
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 17000 flight time type : 300
ASRS Report	146800
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While en route climbing to FL350, the cabin pressure relief open light came on. Checking the operating manual for correct procedure, I switched to standby and up on standby press. Controller to increase cabin altitude and decrease differential pressure. About this time a F/a entered the cockpit whining and complaining for about the fifth time that the in-flight video player wasn't working correctly, having to refund money for headsets, etc. She wanted a foreign air carrier mechanic, who was a passenger to try to fix it. The captain immediately refused to let that happen so I volunteered to go look at it. These distrs caused me to forget about cabin rate of climb. I switched on all hydraulic pumps before leaving F/east panel but forgot to zero the cabin rate of climb. The 'standby on' light was impossible to see because of bright surroundings. At 10000' cabin altitude the red light and horn came on. First officer and captain donned oxygen masks. I was entering cockpit just a the cabin altitude passed 10000'. At about 3000 FPM. I switched standby cabin pressure controller to 'down' and lowered cabin altitude back to normal 5500' for that cruising altitude. At the prevailing aircraft rate of climb, the cabin press relief valve should not have opened and the discrepancy was entered in the aircraft maintenance log. Moral and lessons learned. Don't ever, ever let F/as or other little distrs get in the way of more important business.

Original NASA ASRS Text

Title: CABIN ALT WARNING HORN ALERTS FLT CREW THAT CABIN ALT IS ABOVE 10000'.

Narrative: WHILE ENRTE CLBING TO FL350, THE CABIN PRESSURE RELIEF OPEN LIGHT CAME ON. CHKING THE OPERATING MANUAL FOR CORRECT PROC, I SWITCHED TO STANDBY AND UP ON STANDBY PRESS. CTLR TO INCREASE CABIN ALT AND DECREASE DIFFERENTIAL PRESSURE. ABOUT THIS TIME A F/A ENTERED THE COCKPIT WHINING AND COMPLAINING FOR ABOUT THE FIFTH TIME THAT THE INFLT VIDEO PLAYER WASN'T WORKING CORRECTLY, HAVING TO REFUND MONEY FOR HEADSETS, ETC. SHE WANTED A FOREIGN AIR CARRIER MECH, WHO WAS A PAX TO TRY TO FIX IT. THE CAPT IMMEDIATELY REFUSED TO LET THAT HAPPEN SO I VOLUNTEERED TO GO LOOK AT IT. THESE DISTRS CAUSED ME TO FORGET ABOUT CABIN RATE OF CLB. I SWITCHED ON ALL HYD PUMPS BEFORE LEAVING F/E PANEL BUT FORGOT TO ZERO THE CABIN RATE OF CLB. THE 'STANDBY ON' LIGHT WAS IMPOSSIBLE TO SEE BECAUSE OF BRIGHT SURROUNDINGS. AT 10000' CABIN ALT THE RED LIGHT AND HORN CAME ON. F/O AND CAPT DONNED OXYGEN MASKS. I WAS ENTERING COCKPIT JUST A THE CABIN ALT PASSED 10000'. AT ABOUT 3000 FPM. I SWITCHED STANDBY CABIN PRESSURE CTLR TO 'DOWN' AND LOWERED CABIN ALT BACK TO NORMAL 5500' FOR THAT CRUISING ALT. AT THE PREVAILING ACFT RATE OF CLB, THE CABIN PRESS RELIEF VALVE SHOULD NOT HAVE OPENED AND THE DISCREPANCY WAS ENTERED IN THE ACFT MAINT LOG. MORAL AND LESSONS LEARNED. DON'T EVER, EVER LET F/AS OR OTHER LITTLE DISTRS GET IN THE WAY OF MORE IMPORTANT BUSINESS.

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.