A B737 CREW; CLBING THROUGH 10000 FT; EXPERIENCED THE CAB ALT WARNING HORN. THE RESULT OF LEAVING THE PRESS SWITCH IN THE MANUAL POS.

Narrative

ON DEP FROM ABQ; A WARNING HORN BEGAN TO SOUND SHORTLY AFTER THE FLAPS WERE RAISED. AFTER PASSING 10000 FT I LOOKED UP AND GLANCED AT THE CAB TEMP AND PRESSURE. THE CLB RATE WAS HIGH; ABOUT 2000 FPM; AND CAB ALT WAS HIGH. I AM NOT SURE HOW HIGH; MAYBE 9000 FT. I WAS FLYING. I LOOKED AT THE PACK SWITCHES AND ENG BLEED SWITCHES. THEY WERE IN AUTO AND ON. I WAS GIVEN A VECTOR AND CONCENTRATED ON FLYING THE ACFT. I THOUGHT; IF THE ACFT IS DEPRESSURIZING; WHAT LIGHTS WILL COME ON? THE AUX OXYGEN SYS ON LIGHT. TOO LATE; THE LIGHT WAS ON. WE WERE AROUND 14500 FT. A DSCNT WAS BEGUN. I MADE A CALL TO THE PAX WITH MY OXYGEN MASK ON. AT THE END OF THE ANNOUNCEMENT; I NOTICED THE MIC SWITCH WAS STILL IN BOOM. WE WERE NOW TURNING BASE AND RUNNING CHECKLISTS. ON FINAL I FOUND THE PRESSURE SWITCH IN MANUAL. MY FLOW MUST HAVE BEEN INTERRUPTED DURING THE PRESSURE CHECK AND I DID NOT RETURN TO IT. I DID NOT EVEN CONSIDER THE PRESSURE SWITCH SINCE I 'CHECKED IT' DURING MY FLOW. THE LNDG WAS UNEVENTFUL. DURING AN UNUSUAL SIT; REGARDLESS OF WHAT YOU'RE SURE YOU CHECKED; CHECK IT AGAIN. WHEN INTERRUPTED DURING YOUR FLOW; START OVER FROM THE BEGINNING. WHEN ANY WARNING HORN COMES ON DURING DEP; LEVEL OFF IMMEDIATELY; IF ABLE; AND THEN DO THE TROUBLESHOOTING.