Air carrier crew descends below assigned altitude.

Attributes
ACN	147344
Time
Date	199006
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : lrp
State Reference	PA
Altitude	msl bound lower : 10000 msl bound upper : 11000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	descent other
Route In Use	enroute airway : zny
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 10950 flight time type : 3500
ASRS Report	147344
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
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	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was given a clearance to cross 10 west of lancaster VOR at 11000'. I believe I read back 1100' to ATC, but inadvertently dialed in 10000' on the altitude alerter. The first officer who was flying descended to 1000'. We only discovered our error when we checked in with the next controller. (I might add the first officer checked in as I was calling company and copying the ATIS--have we heard this before?) the controller told us the clearance was 11000' not 10000'. The controller told us to maintain 10000' at that point. I'm filling this report out in the interests of safety, and to add to your data bank. I made a mistake and am confessing. I don't think I will be violated. The controller said nothing about calling him or a violation being filed. I will pay more attention to what my mouth is saying, and what my hand is doing!!

Original NASA ASRS Text

Title: ACR CREW DESCENDS BELOW ASSIGNED ALT.

Narrative: I WAS GIVEN A CLRNC TO CROSS 10 W OF LANCASTER VOR AT 11000'. I BELIEVE I READ BACK 1100' TO ATC, BUT INADVERTENTLY DIALED IN 10000' ON THE ALT ALERTER. THE F/O WHO WAS FLYING DSNDED TO 1000'. WE ONLY DISCOVERED OUR ERROR WHEN WE CHKED IN WITH THE NEXT CTLR. (I MIGHT ADD THE F/O CHKED IN AS I WAS CALLING COMPANY AND COPYING THE ATIS--HAVE WE HEARD THIS BEFORE?) THE CTLR TOLD US THE CLRNC WAS 11000' NOT 10000'. THE CTLR TOLD US TO MAINTAIN 10000' AT THAT POINT. I'M FILLING THIS RPT OUT IN THE INTERESTS OF SAFETY, AND TO ADD TO YOUR DATA BANK. I MADE A MISTAKE AND AM CONFESSING. I DON'T THINK I WILL BE VIOLATED. THE CTLR SAID NOTHING ABOUT CALLING HIM OR A VIOLATION BEING FILED. I WILL PAY MORE ATTN TO WHAT MY MOUTH IS SAYING, AND WHAT MY HAND IS DOING!!

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.