Air carrier medium large transport lost pressurization control on climb out form mdw. Return and lan...

Attributes
ACN	159110
Time
Date	199009
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ord
State Reference	IL
Altitude	msl bound lower : 10000 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord tower : pit
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
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 : 240 flight time total : 12000 flight time type : 560
ASRS Report	159110
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : declared emergency none taken : unable
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

Flight mdw to lax. Climbing out of 10000' to FL230 annunciator (red) cabin altitude light illuminated. Cabin pressure was lost. Stopped climb and leveled at 10500'. Advised ord ATC while manually controling cabin pressurization. Returned to mdw. 12 passenger had ear pain or symptoms and treated by local paramedics. Automatic-pressurization primary controller failed in such a way that it did not xfer to secondary controller or illuminate (blue) controller malfunction or xfer advisory light. Most difficult task was the large # of communications while handling problem; controling aircraft; rerouting for return to mdw; descent, before landing and abnormal checklist; # of communications with F/a; advising passenger that situation was under control and returning to mdw; and advising company maintenance and operations. When an aircraft is experiencing an abnormal flight conditions, minimal frequency changes and communication to minimize distraction from maintaining aircraft control.

Original NASA ASRS Text

Title: ACR MLG LOST PRESSURIZATION CTL ON CLIMB OUT FORM MDW. RETURN AND LAND.

Narrative: FLT MDW TO LAX. CLBING OUT OF 10000' TO FL230 ANNUNCIATOR (RED) CABIN ALT LIGHT ILLUMINATED. CABIN PRESSURE WAS LOST. STOPPED CLB AND LEVELED AT 10500'. ADVISED ORD ATC WHILE MANUALLY CTLING CABIN PRESSURIZATION. RETURNED TO MDW. 12 PAX HAD EAR PAIN OR SYMPTOMS AND TREATED BY LCL PARAMEDICS. AUTO-PRESSURIZATION PRIMARY CTLR FAILED IN SUCH A WAY THAT IT DID NOT XFER TO SECONDARY CTLR OR ILLUMINATE (BLUE) CTLR MALFUNCTION OR XFER ADVISORY LIGHT. MOST DIFFICULT TASK WAS THE LARGE # OF COMS WHILE HANDLING PROB; CTLING ACFT; REROUTING FOR RETURN TO MDW; DSNT, BEFORE LNDG AND ABNORMAL CHKLIST; # OF COMS WITH F/A; ADVISING PAX THAT SITUATION WAS UNDER CTL AND RETURNING TO MDW; AND ADVISING COMPANY MAINT AND OPS. WHEN AN ACFT IS EXPERIENCING AN ABNORMAL FLT CONDITIONS, MINIMAL FREQ CHANGES AND COM TO MINIMIZE DISTR FROM MAINTAINING ACFT CTL.

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.

Air carrier medium large transport lost pressurization control on climb out form mdw. Return and land.