DC10 autoplt failed to capture altitude.

Attributes
ACN	434150
Time
Date	199904
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : trm.vortac
State Reference	CA
Altitude	msl single value : 20000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	DC-10 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : prado
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : commercial pilot : atp pilot : flight engineer pilot : multi engine pilot : instrument
Experience	flight time total : 6600
ASRS Report	434150
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance
Independent Detector	aircraft equipment : altitude alert other flight crewa
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We departed ont airport runway 8R, cleared to the memphis airport via the prado departure. Initial climb was uneventful, with the exception of difficulty in selecting and arming an interim altitude in the FMA. We had been cleared to FL200. We heard the alert horn sound as we approached our preselected altitude of FL200. At this time we were all busy performing various cockpit duties. I happened to look up at the forward panel and noted that the autoplt had failed to capture and hold FL200 and climbed above it. I immediately brought it to the other crew member's attention, who took immediate corrective action. The problem with the autoplt/FMA system was documented and maintenance action taken when we arrived in memphis. The initial difficulty we had in arming the preselected altitude should have triggered our awareness to the situation, and that we might encounter subsequent problems. More situational awareness needed to be present, and not taking for granted the operation of aircraft system.

Original NASA ASRS Text

Title: DC10 AUTOPLT FAILED TO CAPTURE ALT.

Narrative: WE DEPARTED ONT ARPT RWY 8R, CLRED TO THE MEMPHIS ARPT VIA THE PRADO DEP. INITIAL CLB WAS UNEVENTFUL, WITH THE EXCEPTION OF DIFFICULTY IN SELECTING AND ARMING AN INTERIM ALT IN THE FMA. WE HAD BEEN CLRED TO FL200. WE HEARD THE ALERT HORN SOUND AS WE APCHED OUR PRESELECTED ALT OF FL200. AT THIS TIME WE WERE ALL BUSY PERFORMING VARIOUS COCKPIT DUTIES. I HAPPENED TO LOOK UP AT THE FORWARD PANEL AND NOTED THAT THE AUTOPLT HAD FAILED TO CAPTURE AND HOLD FL200 AND CLBED ABOVE IT. I IMMEDIATELY BROUGHT IT TO THE OTHER CREW MEMBER'S ATTN, WHO TOOK IMMEDIATE CORRECTIVE ACTION. THE PROB WITH THE AUTOPLT/FMA SYS WAS DOCUMENTED AND MAINT ACTION TAKEN WHEN WE ARRIVED IN MEMPHIS. THE INITIAL DIFFICULTY WE HAD IN ARMING THE PRESELECTED ALT SHOULD HAVE TRIGGERED OUR AWARENESS TO THE SIT, AND THAT WE MIGHT ENCOUNTER SUBSEQUENT PROBS. MORE SITUATIONAL AWARENESS NEEDED TO BE PRESENT, AND NOT TAKING FOR GRANTED THE OP OF ACFT SYS.

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.