Altitude deviation. Overshoot in climb. Pressurization difficulties.

Attributes
ACN	142611
Time
Date	199004
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : msy
State Reference	LA
Altitude	msl bound lower : 25000 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 10000 flight time type : 5000
ASRS Report	142611
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : overcame equipment problem none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The aircraft was accepted in msy for the flight to mdw with a MEL item which rendered the automatic cabin pressure controller inoperative, during climb out, the first officer, who was controling the cabin pressurization manually, lost control of the cabin, and the master warning light illuminated signalling 'cabin altitude'. While I was regaining control of the cabin, ATC questioned our altitude expecting 25000', since the altitude alert was set for 27000' I indicated we were climbing to FL270. However, due to the pressurization abnormality, I had no recall of the altitude assignment or readback. The problem behind these events revolves around the aircraft operation west/O automatic pressurization. The workload in this 25 yr old, 2-MAN cockpit becomes unacceptably high, during climb and descent, with manual pressurization control.

Original NASA ASRS Text

Title: ALT DEVIATION. OVERSHOOT IN CLIMB. PRESSURIZATION DIFFICULTIES.

Narrative: THE ACFT WAS ACCEPTED IN MSY FOR THE FLT TO MDW WITH A MEL ITEM WHICH RENDERED THE AUTOMATIC CABIN PRESSURE CTLR INOP, DURING CLBOUT, THE F/O, WHO WAS CTLING THE CABIN PRESSURIZATION MANUALLY, LOST CTL OF THE CABIN, AND THE MASTER WARNING LIGHT ILLUMINATED SIGNALLING 'CABIN ALT'. WHILE I WAS REGAINING CTL OF THE CABIN, ATC QUESTIONED OUR ALT EXPECTING 25000', SINCE THE ALT ALERT WAS SET FOR 27000' I INDICATED WE WERE CLBING TO FL270. HOWEVER, DUE TO THE PRESSURIZATION ABNORMALITY, I HAD NO RECALL OF THE ALT ASSIGNMENT OR READBACK. THE PROB BEHIND THESE EVENTS REVOLVES AROUND THE ACFT OPERATION W/O AUTOMATIC PRESSURIZATION. THE WORKLOAD IN THIS 25 YR OLD, 2-MAN COCKPIT BECOMES UNACCEPTABLY HIGH, DURING CLB AND DSNT, WITH MANUAL PRESSURIZATION CTL.

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.