Medium large transport has pressurization flow light activate.

Attributes
ACN	309213
Time
Date	199506
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : phl
State Reference	PA
Altitude	msl bound lower : 20000 msl bound upper : 20000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc tracon : phl
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude descent other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 100 flight time total : 6000 flight time type : 200
ASRS Report	309213
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Climbing out of phl, at 20000 ft, pressurization flow light came on. Noticed cabin altitude at 9000 ft and climbing. Immediately requested descent to 10000 ft. Cabin reached 9500 ft maximum, then descend as we descended. Landed back in phl 2000 pounds above maximum landing weight of 128000 pounds.

Original NASA ASRS Text

Title: MLG HAS PRESSURIZATION FLOW LIGHT ACTIVATE.

Narrative: CLBING OUT OF PHL, AT 20000 FT, PRESSURIZATION FLOW LIGHT CAME ON. NOTICED CABIN ALT AT 9000 FT AND CLBING. IMMEDIATELY REQUESTED DSCNT TO 10000 FT. CABIN REACHED 9500 FT MAX, THEN DSND AS WE DSNDED. LANDED BACK IN PHL 2000 LBS ABOVE MAX LNDG WT OF 128000 LBS.

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.