Altitude deviation excursion from assigned not caught immediately by ARTCC radar controller.

Attributes
ACN	204886
Time
Date	199203
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : cyn
State Reference	NJ
Altitude	msl bound lower : 17000 msl bound upper : 17600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : cfi pilot : commercial pilot : atp
Experience	flight time last 90 days : 79 flight time total : 10000 flight time type : 3500
ASRS Report	204886
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 60 flight time total : 8000 flight time type : 3000
ASRS Report	206052
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	faa : reviewed incident with flight crew Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Flying on a 180 degree heading at 17000 ft to intercept cyn 046 degree radial to cyn ATC reclred us direct to cyn and climb to FL240. Captain readback clearance (PNF). I (first officer flying) proceeded to turn right direct cyn and climbing to 240. At 17600 controller questioned our altitude, he thought we were still assigned 17000 ft (also received TCASII traffic alert). I immediately reversed vertical direction to descend to 17000 ft. Controller later indicated that it was an error on his part. Flight proceeded safely to pbi. Supplemental information from acn 206052. Level 17K on a vector of 180 degrees heading rogered back a clearance to proceed direct cyn and climb to FL240. I responded to departure that we repeated our instructions to climb and proceed to cyn with our call sign included. Initially departure stated we had not done so and would review the tape. Shortly later, he confirmed we had rogered back the clearance with our call sign.

Original NASA ASRS Text

Title: ALTDEV EXCURSION FROM ASSIGNED NOT CAUGHT IMMEDIATELY BY ARTCC RADAR CTLR.

Narrative: FLYING ON A 180 DEG HDG AT 17000 FT TO INTERCEPT CYN 046 DEG RADIAL TO CYN ATC RECLRED US DIRECT TO CYN AND CLB TO FL240. CAPT READBACK CLRNC (PNF). I (FO FLYING) PROCEEDED TO TURN R DIRECT CYN AND CLBING TO 240. AT 17600 CTLR QUESTIONED OUR ALT, HE THOUGHT WE WERE STILL ASSIGNED 17000 FT (ALSO RECEIVED TCASII TFC ALERT). I IMMEDIATELY REVERSED VERT DIRECTION TO DSND TO 17000 FT. CTLR LATER INDICATED THAT IT WAS AN ERROR ON HIS PART. FLT PROCEEDED SAFELY TO PBI. SUPPLEMENTAL INFO FROM ACN 206052. LEVEL 17K ON A VECTOR OF 180 DEGS HDG ROGERED BACK A CLRNC TO PROCEED DIRECT CYN AND CLB TO FL240. I RESPONDED TO DEP THAT WE REPEATED OUR INSTRUCTIONS TO CLB AND PROCEED TO CYN WITH OUR CALL SIGN INCLUDED. INITIALLY DEP STATED WE HAD NOT DONE SO AND WOULD REVIEW THE TAPE. SHORTLY LATER, HE CONFIRMED WE HAD ROGERED BACK THE CLRNC WITH OUR CALL SIGN.

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.