Altitude overshoot over dkk VOR.

Attributes
ACN	496020
Time
Date	200012
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : dkk.vor
State Reference	NY
Altitude	msl bound lower : 10000 msl bound upper : 10700
Environment
Flight Conditions	IMC
Weather Elements	Windshear Ice Snow Thunderstorm
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc tower : tnca.tower
Operator	common carrier : air carrier
Make Model Name	B737-400
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : atp pilot : commercial pilot : cfi pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 18000 flight time type : 12000
ASRS Report	496020
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	altitude deviation : overshoot inflight encounter : weather inflight encounter : turbulence non adherence : clearance
Independent Detector	other controllerb
Resolutory Action	controller : issued new clearance
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Our flight was cleared to cross dunkirk VOR (dkk) at 11000 ft, 250 KTS. First officer PF placed 11000 ft in altitude window and captain (me) PNF pointed and verified 11000 ft. WX at buf was IFR with low ceilings, low visibility, snow, very strong surface winds, moderate icing, and turbulence in clouds. We were still on top in the clear. We began the descent for 11000 ft, briefed the approach, ran preliminary landing checklist, and made a PA to passenger. We set flight attitude down for upcoming turbulence in descent. With all items completed, felt this would be a good opportunity to quickly use the lavatory before entering the clouds and turbulence. Upon return to flight deck, noticed 10000 ft in altitude window. First officer (PF) descending through 10800 ft for 10000 ft. I asked first officer 'did they give us 10000 ft?' response 'yes, 10000 ft.' I asked again, 'did ATC give you 10000 ft?' response 'yes, 10000 ft.' now passing through 10500 ft and leveling before further descent, ATC asked us 'what was your assigned altitude?' based on seeing and confirming 10000 ft with first officer, replied '10000 ft.' ATC replied 'I'll get you clearance to 10000 ft.' (at time no traffic observed on TCASII, 20N mi scale and below.) ATC said 'maintain 10000 ft.' I asked ATC 'any problem sir?' response 'no, not yet,' and they handed me off to buf approach. Upon landing buf, I called ZOB and spoke with a manager who spoke with the controller. Said 'don't worry, there is no problem, sir.' thanked him. I don't know how 10000 ft was selected into the altitude window while I was out of flight deck. I know I saw and verified 11000 ft before I left. My first officer was fairly new -- just over 1 yr. Possibly could have bumped knob with his hand or was busy making FMC entries or second-guessed thinking it was 10000 ft. I don't know. Either way, same story. Always verify and if not sure, simply ask ATC. But based on seeing and verifying with first officer 'did they give us 10000 ft?'' twice and answer was yes, I believed they gave him 10000 ft.

Original NASA ASRS Text

Title: ALT OVERSHOOT OVER DKK VOR.

Narrative: OUR FLT WAS CLRED TO CROSS DUNKIRK VOR (DKK) AT 11000 FT, 250 KTS. FO PF PLACED 11000 FT IN ALT WINDOW AND CAPT (ME) PNF POINTED AND VERIFIED 11000 FT. WX AT BUF WAS IFR WITH LOW CEILINGS, LOW VISIBILITY, SNOW, VERY STRONG SURFACE WINDS, MODERATE ICING, AND TURB IN CLOUDS. WE WERE STILL ON TOP IN THE CLR. WE BEGAN THE DSCNT FOR 11000 FT, BRIEFED THE APCH, RAN PRELIMINARY LNDG CHKLIST, AND MADE A PA TO PAX. WE SET FLT ATTITUDE DOWN FOR UPCOMING TURB IN DSCNT. WITH ALL ITEMS COMPLETED, FELT THIS WOULD BE A GOOD OPPORTUNITY TO QUICKLY USE THE LAVATORY BEFORE ENTERING THE CLOUDS AND TURB. UPON RETURN TO FLT DECK, NOTICED 10000 FT IN ALT WINDOW. FO (PF) DSNDING THROUGH 10800 FT FOR 10000 FT. I ASKED FO 'DID THEY GIVE US 10000 FT?' RESPONSE 'YES, 10000 FT.' I ASKED AGAIN, 'DID ATC GIVE YOU 10000 FT?' RESPONSE 'YES, 10000 FT.' NOW PASSING THROUGH 10500 FT AND LEVELING BEFORE FURTHER DSCNT, ATC ASKED US 'WHAT WAS YOUR ASSIGNED ALT?' BASED ON SEEING AND CONFIRMING 10000 FT WITH FO, REPLIED '10000 FT.' ATC REPLIED 'I'LL GET YOU CLRNC TO 10000 FT.' (AT TIME NO TFC OBSERVED ON TCASII, 20N MI SCALE AND BELOW.) ATC SAID 'MAINTAIN 10000 FT.' I ASKED ATC 'ANY PROB SIR?' RESPONSE 'NO, NOT YET,' AND THEY HANDED ME OFF TO BUF APCH. UPON LNDG BUF, I CALLED ZOB AND SPOKE WITH A MGR WHO SPOKE WITH THE CTLR. SAID 'DON'T WORRY, THERE IS NO PROB, SIR.' THANKED HIM. I DON'T KNOW HOW 10000 FT WAS SELECTED INTO THE ALT WINDOW WHILE I WAS OUT OF FLT DECK. I KNOW I SAW AND VERIFIED 11000 FT BEFORE I LEFT. MY FO WAS FAIRLY NEW -- JUST OVER 1 YR. POSSIBLY COULD HAVE BUMPED KNOB WITH HIS HAND OR WAS BUSY MAKING FMC ENTRIES OR SECOND-GUESSED THINKING IT WAS 10000 FT. I DON'T KNOW. EITHER WAY, SAME STORY. ALWAYS VERIFY AND IF NOT SURE, SIMPLY ASK ATC. BUT BASED ON SEEING AND VERIFYING WITH FO 'DID THEY GIVE US 10000 FT?'' TWICE AND ANSWER WAS YES, I BELIEVED THEY GAVE HIM 10000 FT.

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.