Altitude deviation on descent.

Attributes
ACN	298250
Time
Date	199503
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : rbv airport : ewr
State Reference	NJ
Altitude	msl bound lower : 10000 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-200
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	arrival other arrival star : star enroute airway : zdc
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : cfi pilot : commercial
Experience	flight time last 90 days : 200 flight time total : 9000 flight time type : 2400
ASRS Report	298250
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 210 flight time total : 12000 flight time type : 8000
ASRS Report	298249
Events
Anomaly	altitude deviation : overshoot altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : became reoriented other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

ATC gave us clearance to cross holey at 11000 ft. I dialed 11000 ft in the altitude alert. The captain was reaching down and accidentally knocked the altitude alert to 10000 ft, and I didn't catch it. The autoplt leveled the aircraft off at 10000 ft, and we immediately caught the deviation climbing back to 11000 ft. Factors: end of A3 day trip, and we flew 5 legs that day. Callback conversation with reporter revealed the following information: the reporter flies the B-737-100 and -200 for a major united states air carrier. The first officer had never flown with this captain before, but this had no bearing on the incident. The first officer inserted 11000 ft in the altitude alert and the captain admits that he accidentally moved it to 10000 ft. The first officer did not see any need to rechk the alert as it had been set properly earlier. The first officer believes that the only way to prevent this would be to watch the other pilot's every move, all of the time, an impossible task.

Original NASA ASRS Text

Title: ALTDEV ON DSCNT.

Narrative: ATC GAVE US CLRNC TO CROSS HOLEY AT 11000 FT. I DIALED 11000 FT IN THE ALT ALERT. THE CAPT WAS REACHING DOWN AND ACCIDENTALLY KNOCKED THE ALT ALERT TO 10000 FT, AND I DIDN'T CATCH IT. THE AUTOPLT LEVELED THE ACFT OFF AT 10000 FT, AND WE IMMEDIATELY CAUGHT THE DEV CLBING BACK TO 11000 FT. FACTORS: END OF A3 DAY TRIP, AND WE FLEW 5 LEGS THAT DAY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR FLIES THE B-737-100 AND -200 FOR A MAJOR UNITED STATES ACR. THE FO HAD NEVER FLOWN WITH THIS CAPT BEFORE, BUT THIS HAD NO BEARING ON THE INCIDENT. THE FO INSERTED 11000 FT IN THE ALT ALERT AND THE CAPT ADMITS THAT HE ACCIDENTALLY MOVED IT TO 10000 FT. THE FO DID NOT SEE ANY NEED TO RECHK THE ALERT AS IT HAD BEEN SET PROPERLY EARLIER. THE FO BELIEVES THAT THE ONLY WAY TO PREVENT THIS WOULD BE TO WATCH THE OTHER PLT'S EVERY MOVE, ALL OF THE TIME, AN IMPOSSIBLE TASK.

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.