An A320 crew descending into bwi, overshot assigned altitude.

Attributes
ACN	521300
Time
Date	200108
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bwi.airport
State Reference	MD
Altitude	msl bound lower : 11500 msl bound upper : 12000
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	tracon : bwi.tracon
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : vacating altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain
Qualification	pilot : atp
Experience	flight time type : 7
ASRS Report	521300
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : overrode automation flight crew : returned to assigned altitude
Consequence	other
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During descent into bwi, we were cleared to 11000 ft. Descending through 12500 ft with a 2000 FPM descent rate, approach revised altitude to maintain 12000 ft. PNF set altitude in FCU, PF pointed and repeated altitude per SOP, but we got a mode reversion to vertical speed still in a descent below 12000 ft. PNF pushed takeoff button and reestablished a climb by about 11500 ft. We advised ATC and did not observe any conflicting traffic. Factors that contributed to this area: the screens (pfd nd and FCU) are difficult to see in bright conditions. The SOP's for who sets the altitude in the FCU doesn't allow quick responses to last min ATC altitude requests. The FCU altitude can change with a less than accurate 'pull.' our SOP's require considerable hand crossing at times on the FCU, sometimes obscuring the information. In this case, we discovered the problem immediately but were not able to stop at the assigned altitude because we just didn't have enough time.

Original NASA ASRS Text

Title: AN A320 CREW DSNDING INTO BWI, OVERSHOT ASSIGNED ALT.

Narrative: DURING DSCNT INTO BWI, WE WERE CLRED TO 11000 FT. DSNDING THROUGH 12500 FT WITH A 2000 FPM DSCNT RATE, APCH REVISED ALT TO MAINTAIN 12000 FT. PNF SET ALT IN FCU, PF POINTED AND REPEATED ALT PER SOP, BUT WE GOT A MODE REVERSION TO VERT SPD STILL IN A DSCNT BELOW 12000 FT. PNF PUSHED TKOF BUTTON AND REESTABLISHED A CLB BY ABOUT 11500 FT. WE ADVISED ATC AND DID NOT OBSERVE ANY CONFLICTING TFC. FACTORS THAT CONTRIBUTED TO THIS AREA: THE SCREENS (PFD ND AND FCU) ARE DIFFICULT TO SEE IN BRIGHT CONDITIONS. THE SOP'S FOR WHO SETS THE ALT IN THE FCU DOESN'T ALLOW QUICK RESPONSES TO LAST MIN ATC ALT REQUESTS. THE FCU ALT CAN CHANGE WITH A LESS THAN ACCURATE 'PULL.' OUR SOP'S REQUIRE CONSIDERABLE HAND XING AT TIMES ON THE FCU, SOMETIMES OBSCURING THE INFO. IN THIS CASE, WE DISCOVERED THE PROB IMMEDIATELY BUT WERE NOT ABLE TO STOP AT THE ASSIGNED ALT BECAUSE WE JUST DIDN'T HAVE ENOUGH TIME.

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.