Partial loss of cabin pressure mandates a return land for air carrier medium large transport.

Attributes
ACN	263105
Time
Date	199402
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : djb
State Reference	OH
Altitude	msl bound lower : 22000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude cruise other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 140 flight time total : 7825 flight time type : 1520
ASRS Report	263105
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 6000 flight time type : 1800
ASRS Report	263329
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Shortly after level off, at FL310, we received a cabin altitude alert. The cabin altimeter indicated between 10000 and 11000 ft but was stable/not climbing. Manual operation of the cabin controller had no effect. Cleared to lower altitude, not until passing approximately FL220 did the cabin manual controller respond to our input. At FL200 with the cabin altitude within normal limits and both automatic and manual cabin altitude modes again responsive to input, we informed our dispatcher of the occurrence. After conferring with maintenance, the dispatcher requested that we discontinue the flight and return for maintenance.

Original NASA ASRS Text

Title: PARTIAL LOSS OF CABIN PRESSURE MANDATES A RETURN LAND FOR ACR MLG.

Narrative: SHORTLY AFTER LEVEL OFF, AT FL310, WE RECEIVED A CABIN ALT ALERT. THE CABIN ALTIMETER INDICATED BTWN 10000 AND 11000 FT BUT WAS STABLE/NOT CLBING. MANUAL OP OF THE CABIN CTLR HAD NO EFFECT. CLRED TO LOWER ALT, NOT UNTIL PASSING APPROX FL220 DID THE CABIN MANUAL CTLR RESPOND TO OUR INPUT. AT FL200 WITH THE CABIN ALT WITHIN NORMAL LIMITS AND BOTH AUTO AND MANUAL CABIN ALT MODES AGAIN RESPONSIVE TO INPUT, WE INFORMED OUR DISPATCHER OF THE OCCURRENCE. AFTER CONFERRING WITH MAINT, THE DISPATCHER REQUESTED THAT WE DISCONTINUE THE FLT AND RETURN FOR MAINT.

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.