Altitude deviation altitude excursion overshot.

Attributes
ACN	204928
Time
Date	199203
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	msl bound lower : 5000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 60 flight time total : 4000 flight time type : 41
ASRS Report	204928
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 13000 flight time type : 450
ASRS Report	204942
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Preflight and the before starting engines checklist, power was accidentally removed from aircraft before APU generator came on line. This caused a 10 second (approximately) los of aircraft power which dumped most FMC and ACARS data which had been loaded. We then reloaded and rechked all FMC inputs, causing a 10 min departure delay. On taxi out we completed the remaining checklists, but failed to notice that the power loss had changed the takeoff altitude on the AFDS panel. The power loss changed our altitude on the AFDS panel from the previously set 5000 ft to 10000 ft. When doing checklist I called for the checklist item AFDS panel on the before takeoff checklist. The captain read off what was in AFDS windows V2 or 135/runway heading of 090/and altitude 10000 and everything seemed to register as correct, but part of my concentration was distraction by dumped ACARS data. I was attempting to reload, radio calls, clearing for taxiing aircraft on a very busy night. Shortly thereafter we were cleared for takeoff. I was flying the leg and I noticed the captain called departure about 4 times with no luck in getting through. When he finally got through I was flying through 6000 for 10000 when the controller asked what we were doing. The captain replied that 10000 was our cleared altitude. I feel that this problem was caused by the power loss which changed the altitude from 5000 to 10000 on the AFDS panel and distrs caused by the increased workload generated by reloading and rechking all FMC and ACARS data after departure time and during taxi out. Supplemental information from acn 204942. When doing AFDS panel check I called out altitude 10000 ft but this did not register as incorrect as I assumed copilot had reset new altitude. The error, in my opinion, was generated by the altitude shift from 5000 to 10000 caused by the electric power shift and our distraction caused by the increased workload and being unable to contact departure control immediately.

Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION OVERSHOT.

Narrative: PREFLT AND THE BEFORE STARTING ENGS CHKLIST, PWR WAS ACCIDENTALLY REMOVED FROM ACFT BEFORE APU GENERATOR CAME ON LINE. THIS CAUSED A 10 SECOND (APPROX) LOS OF ACFT PWR WHICH DUMPED MOST FMC AND ACARS DATA WHICH HAD BEEN LOADED. WE THEN RELOADED AND RECHKED ALL FMC INPUTS, CAUSING A 10 MIN DEP DELAY. ON TAXI OUT WE COMPLETED THE REMAINING CHKLISTS, BUT FAILED TO NOTICE THAT THE PWR LOSS HAD CHANGED THE TKOF ALT ON THE AFDS PANEL. THE PWR LOSS CHANGED OUR ALT ON THE AFDS PANEL FROM THE PREVIOUSLY SET 5000 FT TO 10000 FT. WHEN DOING CHKLIST I CALLED FOR THE CHKLIST ITEM AFDS PANEL ON THE BEFORE TKOF CHKLIST. THE CAPT READ OFF WHAT WAS IN AFDS WINDOWS V2 OR 135/RWY HDG OF 090/AND ALT 10000 AND EVERYTHING SEEMED TO REGISTER AS CORRECT, BUT PART OF MY CONCENTRATION WAS DISTR BY DUMPED ACARS DATA. I WAS ATTEMPTING TO RELOAD, RADIO CALLS, CLRING FOR TAXIING ACFT ON A VERY BUSY NIGHT. SHORTLY THEREAFTER WE WERE CLRED FOR TKOF. I WAS FLYING THE LEG AND I NOTICED THE CAPT CALLED DEP ABOUT 4 TIMES WITH NO LUCK IN GETTING THROUGH. WHEN HE FINALLY GOT THROUGH I WAS FLYING THROUGH 6000 FOR 10000 WHEN THE CTLR ASKED WHAT WE WERE DOING. THE CAPT REPLIED THAT 10000 WAS OUR CLRED ALT. I FEEL THAT THIS PROBLEM WAS CAUSED BY THE PWR LOSS WHICH CHANGED THE ALT FROM 5000 TO 10000 ON THE AFDS PANEL AND DISTRS CAUSED BY THE INCREASED WORKLOAD GENERATED BY RELOADING AND RECHKING ALL FMC AND ACARS DATA AFTER DEP TIME AND DURING TAXI OUT. SUPPLEMENTAL INFO FROM ACN 204942. WHEN DOING AFDS PANEL CHK I CALLED OUT ALT 10000 FT BUT THIS DID NOT REGISTER AS INCORRECT AS I ASSUMED COPLT HAD RESET NEW ALT. THE ERROR, IN MY OPINION, WAS GENERATED BY THE ALT SHIFT FROM 5000 TO 10000 CAUSED BY THE ELECTRIC PWR SHIFT AND OUR DISTR CAUSED BY THE INCREASED WORKLOAD AND BEING UNABLE TO CONTACT DEP CTL IMMEDIATELY.

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.