Altitude deviation.

Attributes
ACN	145011
Time
Date	199005
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zoa
State Reference	CA
Altitude	msl bound lower : 23000 msl bound upper : 24000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	common carrier : air carrier
Make Model Name	Medium Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 100 flight time total : 15000 flight time type : 7000
ASRS Report	145011
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : atp pilot : commercial
Experience	flight time last 90 days : 105 flight time total : 11000 flight time type : 4800
ASRS Report	145435
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation

Narrative:

We were given a climb to our cruise altitude (less than the altitude filed). We were busy in the departure sequence as our rate of climb was 4000-6000 FPM. Departing from a 6000' airport and climbing VFR to 12000--it was busy. We climbed to 24000', leveled off and got a call from ZOA asking us our flight level. We replied 24000' and he said our assigned altitude was 23000'. We then descended to FL230. I do not know whether we read the clearance back correctly or not, or whether we (the first officer) inadvertently set 24000' in the altitude control window. I do not now who's mistake it was. Center said to descend to FL230, and we did west/O delay. Note: the altitude alert window on this medium large transport is difficult to read in some lighting conditions and sensitive to the slightest inadvertent finger touch.

Original NASA ASRS Text

Title: ALT DEVIATION.

Narrative: WE WERE GIVEN A CLB TO OUR CRUISE ALT (LESS THAN THE ALT FILED). WE WERE BUSY IN THE DEP SEQUENCE AS OUR RATE OF CLB WAS 4000-6000 FPM. DEPARTING FROM A 6000' ARPT AND CLBING VFR TO 12000--IT WAS BUSY. WE CLBED TO 24000', LEVELED OFF AND GOT A CALL FROM ZOA ASKING US OUR FLT LEVEL. WE REPLIED 24000' AND HE SAID OUR ASSIGNED ALT WAS 23000'. WE THEN DSNDED TO FL230. I DO NOT KNOW WHETHER WE READ THE CLRNC BACK CORRECTLY OR NOT, OR WHETHER WE (THE F/O) INADVERTENTLY SET 24000' IN THE ALT CTL WINDOW. I DO NOT NOW WHO'S MISTAKE IT WAS. CENTER SAID TO DSND TO FL230, AND WE DID W/O DELAY. NOTE: THE ALT ALERT WINDOW ON THIS MLG IS DIFFICULT TO READ IN SOME LIGHTING CONDITIONS AND SENSITIVE TO THE SLIGHTEST INADVERTENT FINGER TOUCH.

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.