A B737-300 pressurization system failed at FL350 so an emergency was declared; a descent begun and t...

Narrative:

FL350 aircraft experienced gradual loss of cabin pressurization. Pilots donned masks after cabin altitude warning horn sounded and ran QRH checklist for loss pressurization. It was not a rapid depressurization; emergency descent into ZZZ. No problems with communication between pilots; flight attendants; or ATC. [We] declared an emergency. Cabin climbed to 15;000 ft as we passed fl 180. [We] made a slow emergency descent as we were descending into thunderstorms. Cabin depressurized at 1;000-1;500 FPM the entire time. Removed masks below 10;000 ft. [We] landed on the runway with thunderstorms near airport. [We] had a 16 KT tailwind on landing with shifting winds. Decided to land with tailwind; as I was concerned with 122 people onboard that someone may have needed medical attention. Paramedics met us at the gate and three people were examined; released; and no one was transported. Coordinated with dispatch and maintenance control and recorded the event in the logbook.

Original NASA ASRS Text

Title: A B737-300 pressurization system failed at FL350 so an emergency was declared; a descent begun and the QRH completed as they diverted to a nearby airport. The cabin and aircraft altitudes met at 15;000 FT.

Narrative: FL350 aircraft experienced gradual loss of cabin pressurization. Pilots donned masks after Cabin Altitude Warning horn sounded and ran QRH Checklist for Loss Pressurization. It was not a rapid depressurization; emergency descent into ZZZ. No problems with communication between pilots; flight attendants; or ATC. [We] declared an emergency. Cabin climbed to 15;000 FT as we passed FL 180. [We] made a slow emergency descent as we were descending into thunderstorms. Cabin depressurized at 1;000-1;500 FPM the entire time. Removed masks below 10;000 FT. [We] landed on the runway with thunderstorms near airport. [We] had a 16 KT tailwind on landing with shifting winds. Decided to land with tailwind; as I was concerned with 122 people onboard that someone may have needed medical attention. Paramedics met us at the gate and three people were examined; released; and no one was transported. Coordinated with Dispatch and Maintenance Control and recorded the event in the logbook.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1004952
Time
Date	201204
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Pressurization System
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 324 Flight Crew Type 10000
Person 2
Function	First Officer
Experience	Flight Crew Last 90 Days 146
Events
Anomaly	Aircraft Equipment Problem Critical

A B737-300 pressurization system failed at FL350 so an emergency was declared; a descent begun and the QRH completed as they diverted to a nearby airport. The cabin and aircraft altitudes met at 15;000 ft.