Air carrier climbs above assigned altitude, turns off transponder.

Attributes
ACN	224117
Time
Date	199210
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : las
State Reference	NV
Altitude	msl bound lower : 33000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla tower : hpn
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : flight engineer
Experience	flight time last 90 days : 160 flight time total : 16000 flight time type : 4000
ASRS Report	224117
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Leveling off at FL330 on airway to las en route to slc, I called 1000 ft to level off and the captain acknowledged. I observed him leveling at our assigned FL330 and pushing what I thought was the altitude hold button. Looking away at some other item, the so said, weren't we to level at FL330, and the captain said he thought he hit altitude hold but we were at FL333 and slowly climbing, which we corrected immediately as ATC called us and asked our altitude which we said was FL330 and turned off the transponder and stated we were resetting it as we were at FL330 then. The problem was probably due to the captain hitting the heading select switch right next to the altitude hold switch on the older autoplt on the large transport. Short of a design or newer autoplt change, the only fix would be increased crew awareness at all level offs.

Original NASA ASRS Text

Title: ACR CLBS ABOVE ASSIGNED ALT, TURNS OFF TRANSPONDER.

Narrative: LEVELING OFF AT FL330 ON AIRWAY TO LAS ENRTE TO SLC, I CALLED 1000 FT TO LEVEL OFF AND THE CAPT ACKNOWLEDGED. I OBSERVED HIM LEVELING AT OUR ASSIGNED FL330 AND PUSHING WHAT I THOUGHT WAS THE ALT HOLD BUTTON. LOOKING AWAY AT SOME OTHER ITEM, THE SO SAID, WEREN'T WE TO LEVEL AT FL330, AND THE CAPT SAID HE THOUGHT HE HIT ALT HOLD BUT WE WERE AT FL333 AND SLOWLY CLBING, WHICH WE CORRECTED IMMEDIATELY AS ATC CALLED US AND ASKED OUR ALT WHICH WE SAID WAS FL330 AND TURNED OFF THE TRANSPONDER AND STATED WE WERE RESETTING IT AS WE WERE AT FL330 THEN. THE PROBLEM WAS PROBABLY DUE TO THE CAPT HITTING THE HDG SELECT SWITCH RIGHT NEXT TO THE ALT HOLD SWITCH ON THE OLDER AUTOPLT ON THE LGT. SHORT OF A DESIGN OR NEWER AUTOPLT CHANGE, THE ONLY FIX WOULD BE INCREASED CREW AWARENESS AT ALL LEVEL OFFS.

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.