An A319 crew, descending into lga, overshot their assigned altitude.

Attributes
ACN	538123
Time
Date	200202
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : ign.vor
State Reference	NY
Altitude	msl bound lower : 15850 msl bound upper : 16250
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw.artcc tower : pbi.tower
Operator	common carrier : air carrier
Make Model Name	A319
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 160 flight time total : 18000 flight time type : 800
ASRS Report	538123
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	altitude deviation : overshoot inflight encounter : weather inflight encounter other non adherence : company policies non adherence : clearance
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance Weather
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was first officer of a flight en route bos-lga at 16000 ft MSL. We had been given multiple altimeter changes as we progressed towards a vigorous low pressure system and, as a result, our indicated altitude was 15850 ft MSL. In order to correct back to our assigned altitude I selected 200 FPM vertical speed for a gentle correction. Immediately thereafter I pointed out to the captain that the ILS identifier did not agree with the approach we had briefed and he proceeded to get the new ATIS, while I prepared for the new approach briefing. 2 mins elapsed when the altitude alerter sounded because we had, for some reason, climbed through our selected/assigned altitude of 16000 ft to 16250 ft. I pushed the leveloff knob and selected a vertical speed to take us back down to 16000 ft. Shortly thereafter ZBW assigned us the customary 14000 ft as we were getting close to the destination. No mention was made of our excursion to 16250 ft and traffic was noted in our area on TCASII. I have no idea why the aircraft failed to level off at the selected altitude. I do not recall looking for the blue 'altitude' capture armed indication when I selected the climb. Preparing for the new approach while climbing was certainly not a good idea and, I will be monitoring climbs/dscnts more closely in the future.

Original NASA ASRS Text

Title: AN A319 CREW, DSNDING INTO LGA, OVERSHOT THEIR ASSIGNED ALT.

Narrative: I WAS FO OF A FLT ENRTE BOS-LGA AT 16000 FT MSL. WE HAD BEEN GIVEN MULTIPLE ALTIMETER CHANGES AS WE PROGRESSED TOWARDS A VIGOROUS LOW PRESSURE SYS AND, AS A RESULT, OUR INDICATED ALT WAS 15850 FT MSL. IN ORDER TO CORRECT BACK TO OUR ASSIGNED ALT I SELECTED 200 FPM VERT SPD FOR A GENTLE CORRECTION. IMMEDIATELY THEREAFTER I POINTED OUT TO THE CAPT THAT THE ILS IDENTIFIER DID NOT AGREE WITH THE APCH WE HAD BRIEFED AND HE PROCEEDED TO GET THE NEW ATIS, WHILE I PREPARED FOR THE NEW APCH BRIEFING. 2 MINS ELAPSED WHEN THE ALT ALERTER SOUNDED BECAUSE WE HAD, FOR SOME REASON, CLBED THROUGH OUR SELECTED/ASSIGNED ALT OF 16000 FT TO 16250 FT. I PUSHED THE LEVELOFF KNOB AND SELECTED A VERT SPD TO TAKE US BACK DOWN TO 16000 FT. SHORTLY THEREAFTER ZBW ASSIGNED US THE CUSTOMARY 14000 FT AS WE WERE GETTING CLOSE TO THE DEST. NO MENTION WAS MADE OF OUR EXCURSION TO 16250 FT AND TFC WAS NOTED IN OUR AREA ON TCASII. I HAVE NO IDEA WHY THE ACFT FAILED TO LEVEL OFF AT THE SELECTED ALT. I DO NOT RECALL LOOKING FOR THE BLUE 'ALT' CAPTURE ARMED INDICATION WHEN I SELECTED THE CLB. PREPARING FOR THE NEW APCH WHILE CLBING WAS CERTAINLY NOT A GOOD IDEA AND, I WILL BE MONITORING CLBS/DSCNTS MORE CLOSELY IN THE FUTURE.

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.