Narrative:

Second officer set aircraft land altitude window (pressurization) to 25' instead of the required 4025'. When aircraft fwd cargo door was opened by ground crew, aircraft depressurized and blow out the fwd cargo ceiling panels. The #2 engine was still running with APU not running (as per directive) while waiting for ground power to be connected. A mild muffled explosion was experienced as we depressurized. Flight land switch was placed to ground upon landing. Supplemental information from acn 160723. The second officer was new and not familiar with salt lake's higher filed elevation. Supplemental information from acn 161089. Our aircraft had a relatively short taxi to the gate. After clearing the runway, the flight/ground switch was placed in the ground position, which should have opened the outflow valve, and depressurized the aircraft, but for some reason it did not completely depressurize until the cargo door was opened. The blow-out panels in the cargo bay were blown out, but no injuries occurred. The outflow valve worked properly on preflight and after the incident maintenance checked it and said it works properly. Although it is not specifically required to check the cabin differential pressure after landing, good judgement would dictate that you should (and I did not do this).

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Original NASA ASRS Text

Title: IMPROPER PRESSURIZATION DEPRESSURIZATION PROC LEADS TO CABIN BAGGAGE COMPARTMENT BLOWOUT AT GATE IN SLC.

Narrative: S/O SET ACFT LAND ALT WINDOW (PRESSURIZATION) TO 25' INSTEAD OF THE REQUIRED 4025'. WHEN ACFT FWD CARGO DOOR WAS OPENED BY GND CREW, ACFT DEPRESSURIZED AND BLOW OUT THE FWD CARGO CEILING PANELS. THE #2 ENG WAS STILL RUNNING WITH APU NOT RUNNING (AS PER DIRECTIVE) WHILE WAITING FOR GND PWR TO BE CONNECTED. A MILD MUFFLED EXPLOSION WAS EXPERIENCED AS WE DEPRESSURIZED. FLT LAND SWITCH WAS PLACED TO GND UPON LNDG. SUPPLEMENTAL INFO FROM ACN 160723. THE S/O WAS NEW AND NOT FAMILIAR WITH SALT LAKE'S HIGHER FILED ELEVATION. SUPPLEMENTAL INFO FROM ACN 161089. OUR ACFT HAD A RELATIVELY SHORT TAXI TO THE GATE. AFTER CLRING THE RWY, THE FLT/GND SWITCH WAS PLACED IN THE GND POS, WHICH SHOULD HAVE OPENED THE OUTFLOW VALVE, AND DEPRESSURIZED THE ACFT, BUT FOR SOME REASON IT DID NOT COMPLETELY DEPRESSURIZE UNTIL THE CARGO DOOR WAS OPENED. THE BLOW-OUT PANELS IN THE CARGO BAY WERE BLOWN OUT, BUT NO INJURIES OCCURRED. THE OUTFLOW VALVE WORKED PROPERLY ON PREFLT AND AFTER THE INCIDENT MAINT CHKED IT AND SAID IT WORKS PROPERLY. ALTHOUGH IT IS NOT SPECIFICALLY REQUIRED TO CHK THE CABIN DIFFERENTIAL PRESSURE AFTER LNDG, GOOD JUDGEMENT WOULD DICTATE THAT YOU SHOULD (AND I DID NOT DO THIS).

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.