DC9 crew was required to make a rapid descent when the aircraft cabin began to climb unctlably. The ...

Attributes
ACN	404306
Time
Date	199805
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : phl
State Reference	PA
Altitude	msl bound lower : 13000 msl bound upper : 29000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise other descent other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 150 flight time total : 6000 flight time type : 700
ASRS Report	404306
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical altitude deviation : overshoot non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : declared emergency flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

En route from mke to phl, large areas of thunderstorms. We had to deviate considerably. Several mechanical discrepancies occurred in-flight in a relatively short time period. 1) ram air temperature/EPR gauge became inoperative. 2) #2 radio knob broke leaving us with only one. 3) windshear detection system failed. Then the cabin pressure started climbing slowly while in cruise (altitude approximately FL290). We completed memory items and some troubleshooting to no avail. We requested an immediate descent to a lower altitude. Due to traffic in the area, we were held up for 2-3 mins while the cabin was still climbing. ATC then cleared us to 13000 ft. We made an expeditious descent. During descent the cabin began to stabilize and eventually worked sufficiently. Upon descending through FL180, both crew members forgot to reset their altimeters to 29.62 putting us 300 ft low at 13000 ft. I don't believe any conflicts occurred. The reason for this omission was probably caused by the numerous distrs (mechanicals, WX, etc), primarily the cabin altitude problem. To prevent this from occurring again, I will concentrate on several things during any abnormality or emergency. 1) delegate tasks -- have one person focus on flying the airplane while the other troubleshoots, etc. State clearly who will be doing what, ie, 'you talk to ATC, I'll talk to the flight attendants.' 'you fly the airplane, I'll run the checklist.' 2) strict adherence to company procedures (altitude callouts, etc) during any abnormality.

Original NASA ASRS Text

Title: DC9 CREW WAS REQUIRED TO MAKE A RAPID DSCNT WHEN THE ACFT CABIN BEGAN TO CLB UNCTLABLY. THE CREW DID NOT MAKE THE APPROPRIATE ALTIMETER SETTING, AT THE TRANSITION ALT, WHILE MAKING THE DSCNT, RESULTING IN A LEVELOFF 300 FT LOW.

Narrative: ENRTE FROM MKE TO PHL, LARGE AREAS OF TSTMS. WE HAD TO DEVIATE CONSIDERABLY. SEVERAL MECHANICAL DISCREPANCIES OCCURRED INFLT IN A RELATIVELY SHORT TIME PERIOD. 1) RAM AIR TEMP/EPR GAUGE BECAME INOP. 2) #2 RADIO KNOB BROKE LEAVING US WITH ONLY ONE. 3) WINDSHEAR DETECTION SYS FAILED. THEN THE CABIN PRESSURE STARTED CLBING SLOWLY WHILE IN CRUISE (ALT APPROX FL290). WE COMPLETED MEMORY ITEMS AND SOME TROUBLESHOOTING TO NO AVAIL. WE REQUESTED AN IMMEDIATE DSCNT TO A LOWER ALT. DUE TO TFC IN THE AREA, WE WERE HELD UP FOR 2-3 MINS WHILE THE CABIN WAS STILL CLBING. ATC THEN CLRED US TO 13000 FT. WE MADE AN EXPEDITIOUS DSCNT. DURING DSCNT THE CABIN BEGAN TO STABILIZE AND EVENTUALLY WORKED SUFFICIENTLY. UPON DSNDING THROUGH FL180, BOTH CREW MEMBERS FORGOT TO RESET THEIR ALTIMETERS TO 29.62 PUTTING US 300 FT LOW AT 13000 FT. I DON'T BELIEVE ANY CONFLICTS OCCURRED. THE REASON FOR THIS OMISSION WAS PROBABLY CAUSED BY THE NUMEROUS DISTRS (MECHANICALS, WX, ETC), PRIMARILY THE CABIN ALT PROB. TO PREVENT THIS FROM OCCURRING AGAIN, I WILL CONCENTRATE ON SEVERAL THINGS DURING ANY ABNORMALITY OR EMER. 1) DELEGATE TASKS -- HAVE ONE PERSON FOCUS ON FLYING THE AIRPLANE WHILE THE OTHER TROUBLESHOOTS, ETC. STATE CLRLY WHO WILL BE DOING WHAT, IE, 'YOU TALK TO ATC, I'LL TALK TO THE FLT ATTENDANTS.' 'YOU FLY THE AIRPLANE, I'LL RUN THE CHKLIST.' 2) STRICT ADHERENCE TO COMPANY PROCS (ALT CALLOUTS, ETC) DURING ANY ABNORMALITY.

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.

DC9 crew was required to make a rapid descent when the aircraft cabin began to climb unctlably. The crew did not make the appropriate altimeter setting, at the transition altitude, while making the descent, resulting in a leveloff 300 ft low.