An air carrier flight crew departing lga in an MD88 reports conflicting climb instructions from ATC.

Attributes
ACN	483820
Time
Date	200009
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : lga.vor
State Reference	NY
Altitude	msl bound lower : 12000 msl bound upper : 12800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90.tracon tower : ito.tower
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	climbout : intermediate altitude climbout : vacating altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer pilot : multi engine
Experience	flight time last 90 days : 240 flight time total : 5045 flight time type : 2075
ASRS Report	483820
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer pilot : multi engine
Experience	flight time last 90 days : 250 flight time total : 11500 flight time type : 1300
ASRS Report	483821
Events
Anomaly	other anomaly other
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : returned to original clearance
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

Departed lga runway 31 and vectored through a 270 degree right turn during climb. We were on a 230 degree heading and level at 12000 ft when new york departure gave us 'fly heading 250 degrees, climb to 16000 ft.' passing about 12700 ft, they said 'maintain 12000 ft.' we acknowledged and began descent to 12000 ft. The captain and I were certain we had heard 16000 ft and mentioned that to the controller. He did not disagree and simply told us to maintain 12000 ft. Supplemental information from acn 483821: I mentioned to the controller that we had heard and acknowledged 16000 ft. He said just to maintain 12000 ft. Both the first officer and myself were certain of the clearance to 16000 ft and were exercising extra diligence since the controller's xmissions were weak at the beginning of every transmission.

Original NASA ASRS Text

Title: AN ACR FLC DEPARTING LGA IN AN MD88 RPTS CONFLICTING CLB INSTRUCTIONS FROM ATC.

Narrative: DEPARTED LGA RWY 31 AND VECTORED THROUGH A 270 DEG R TURN DURING CLB. WE WERE ON A 230 DEG HDG AND LEVEL AT 12000 FT WHEN NEW YORK DEP GAVE US 'FLY HDG 250 DEGS, CLB TO 16000 FT.' PASSING ABOUT 12700 FT, THEY SAID 'MAINTAIN 12000 FT.' WE ACKNOWLEDGED AND BEGAN DSCNT TO 12000 FT. THE CAPT AND I WERE CERTAIN WE HAD HEARD 16000 FT AND MENTIONED THAT TO THE CTLR. HE DID NOT DISAGREE AND SIMPLY TOLD US TO MAINTAIN 12000 FT. SUPPLEMENTAL INFO FROM ACN 483821: I MENTIONED TO THE CTLR THAT WE HAD HEARD AND ACKNOWLEDGED 16000 FT. HE SAID JUST TO MAINTAIN 12000 FT. BOTH THE FO AND MYSELF WERE CERTAIN OF THE CLRNC TO 16000 FT AND WERE EXERCISING EXTRA DILIGENCE SINCE THE CTLR'S XMISSIONS WERE WEAK AT THE BEGINNING OF EVERY XMISSION.

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.