An MD88 on climb out incurred an altitude deviation while attempting to correct a pressurization mal...

Attributes
ACN	620755
Time
Date	200406
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dca.airport
State Reference	DC
Altitude	msl bound lower : 5000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pct.tracon
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 273 flight time total : 14660 flight time type : 7560
ASRS Report	620755
Person 2
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical altitude deviation : overshoot non adherence : far non adherence : published procedure non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : f/o altimeter other flight crewa other flight crewb
Resolutory Action	controller : issued advisory controller : issued new clearance flight crew : became reoriented flight crew : overcame equipment problem flight crew : overrode automation
Consequence	other other
Supplementary
Problem Areas	Flight Crew Human Performance Environmental Factor Aircraft
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

After takeoff from washington national, we noticed that the aircraft was not pressurizing. There were no lights or other warnings, only the pressure changes in our ears. I told first officer to engage the autoplt while I checked the pressurization system. Not able to determine what was wrong with the automatic-pressure system, I went to manual pressurization control, which takes most of my awareness initially. Departure asked about our altitude. We had leveled at 6000 ft. The clearance was for 5000 ft. There was no traffic conflicts so departure had us remain at 6000 ft. We know we had 5000 ft set before takeoff and think that the first officer bumped the altitude set knob, which is right next to the autoplt switch when he engaged the autoplt. Even though we had separated the duties between flying/communication and working on the pressurization problem, it was still very distracting because of the discomfort in our ears and not wanting the cabin pressure to climb anymore. As a result, neither one of us noticed that the altitude was incorrect.

Original NASA ASRS Text

Title: AN MD88 ON CLBOUT INCURRED AN ALTDEV WHILE ATTEMPTING TO CORRECT A PRESSURIZATION MALFUNCTION.

Narrative: AFTER TKOF FROM WASHINGTON NATIONAL, WE NOTICED THAT THE ACFT WAS NOT PRESSURIZING. THERE WERE NO LIGHTS OR OTHER WARNINGS, ONLY THE PRESSURE CHANGES IN OUR EARS. I TOLD FO TO ENGAGE THE AUTOPLT WHILE I CHKED THE PRESSURIZATION SYS. NOT ABLE TO DETERMINE WHAT WAS WRONG WITH THE AUTO-PRESSURE SYS, I WENT TO MANUAL PRESSURIZATION CTL, WHICH TAKES MOST OF MY AWARENESS INITIALLY. DEP ASKED ABOUT OUR ALT. WE HAD LEVELED AT 6000 FT. THE CLRNC WAS FOR 5000 FT. THERE WAS NO TFC CONFLICTS SO DEP HAD US REMAIN AT 6000 FT. WE KNOW WE HAD 5000 FT SET BEFORE TKOF AND THINK THAT THE FO BUMPED THE ALT SET KNOB, WHICH IS RIGHT NEXT TO THE AUTOPLT SWITCH WHEN HE ENGAGED THE AUTOPLT. EVEN THOUGH WE HAD SEPARATED THE DUTIES BTWN FLYING/COM AND WORKING ON THE PRESSURIZATION PROB, IT WAS STILL VERY DISTRACTING BECAUSE OF THE DISCOMFORT IN OUR EARS AND NOT WANTING THE CABIN PRESSURE TO CLB ANYMORE. AS A RESULT, NEITHER ONE OF US NOTICED THAT THE ALT WAS INCORRECT.

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.

An MD88 on climb out incurred an altitude deviation while attempting to correct a pressurization malfunction.