Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
Aircraft Equipment Problem Critical
Flight Crew Returned To Departure Airport; General Declared Emergency
Aircraft
Approximately 5 minutes after level off at FL330; an intermittent [cabin altitude] warning horn sounded. QRC items were accomplished; but unable to control cabin altitude in standby. Cabin altitude [was] at approximately 11;000 FT.Informed ATC of problem and requested descent to 10;000 FT and were told to stand by. We were able to see the mountain visually in the sunrise and on our terrain display well to the south; so we requested and were denied descent again.Since we could observe no traffic below us on TCAS we declared an emergency and commenced emergency descent to 10;000 FT. We regained control of the cabin after leveling at 10;000 FT in manual AC mode. Flight attendants notified and reported feeling light headed. We decided to return to our departure airport where we made a normal landing.
[Narrative #2 had no additional information.]
When ATC failed to clear them for their requested descent to 10;000 FT; the flight crew of a B737-400; unable to control their pressurization; declared an emergency and initiated their descent.