B757-200 returns to departure airport when pressurization system fails on climbout.

Attributes
ACN	798866
Time
Date	200808
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 20000
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	798866
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	798861
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : declared emergency other
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

On initial climb out; there was no airflow in the cockpit. Air sucking from cockpit gasper vents. Cabin altitude indications normal. At last chkout of about 14000 ft; cabin altitude was still normal; but with same air flow problem. Out of about FL200; cabin altitude warning sounded and cabin altitude was about 10000 ft. Passenger oxygen masks were not deployed. Declared emergency and performed emergency descent and returned to ZZZ uneventfully with an overweight landing.

Original NASA ASRS Text

Title: B757-200 RETURNS TO DEP ARPT WHEN PRESSURIZATION SYSTEM FAILS ON CLIMBOUT.

Narrative: ON INITIAL CLBOUT; THERE WAS NO AIRFLOW IN THE COCKPIT. AIR SUCKING FROM COCKPIT GASPER VENTS. CABIN ALT INDICATIONS NORMAL. AT LAST CHKOUT OF ABOUT 14000 FT; CABIN ALT WAS STILL NORMAL; BUT WITH SAME AIR FLOW PROB. OUT OF ABOUT FL200; CABIN ALT WARNING SOUNDED AND CABIN ALT WAS ABOUT 10000 FT. PAX OXYGEN MASKS WERE NOT DEPLOYED. DECLARED EMER AND PERFORMED EMER DSCNT AND RETURNED TO ZZZ UNEVENTFULLY WITH AN OVERWT LNDG.

Data retrieved from NASA's ASRS site as of May 2009 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.