Pilots misunderstood altitude clearance issued by ATC.

Attributes
ACN	544682
Time
Date	200204
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : pae.airport
State Reference	WA
Altitude	agl single value : 0 msl bound lower : 2000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : pae.tower tower : tpa.tower
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	climbout : initial climbout : intermediate altitude climbout : takeoff ground : takeoff roll ground : position and hold
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : multi engine pilot : atp
Experience	flight time last 90 days : 75 flight time total : 13000 flight time type : 1900
ASRS Report	544682
Person 2
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : far non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance controller : issued advisory flight crew : returned to assigned altitude
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:

Advised to maintain 3000 ft on departure from pae clearance delivery. Short taxi to runway when tower advised to maintain 3000 ft and turn right to 210 degrees when leaving 2000 ft. Asked the first officer to verify clearance as it was garbled, and clarify whether we wre cleared for takeoff. Tower controller from our vantage point stated to turn right to 210 degrees after leaving 2000 ft and maintain 3000 ft. The first officer did not clearly understand second issuance of altitude, as multiple instructions were issued fairly rapidly. On departure, we maintained 3000 ft and were advised by departure that we were to maintain 2000 ft. The tower and center were called to verify when our clearance changed to 2000 ft. They advised when we were given traffic information on takeoff the new altitude was given. It is apparent that the clearance was not clearly understood by both pilots. When rapid and multiple instructions are given by ATC at takeoff, all ambiguity must be verified. It would help if TA's and actual clrncs are separate xmissions when workload is high in the automated cockpit.

Original NASA ASRS Text

Title: PLTS MISUNDERSTOOD ALT CLRNC ISSUED BY ATC.

Narrative: ADVISED TO MAINTAIN 3000 FT ON DEP FROM PAE CLRNC DELIVERY. SHORT TAXI TO RWY WHEN TWR ADVISED TO MAINTAIN 3000 FT AND TURN R TO 210 DEGS WHEN LEAVING 2000 FT. ASKED THE FO TO VERIFY CLRNC AS IT WAS GARBLED, AND CLARIFY WHETHER WE WRE CLRED FOR TKOF. TWR CTLR FROM OUR VANTAGE POINT STATED TO TURN R TO 210 DEGS AFTER LEAVING 2000 FT AND MAINTAIN 3000 FT. THE FO DID NOT CLRLY UNDERSTAND SECOND ISSUANCE OF ALT, AS MULTIPLE INSTRUCTIONS WERE ISSUED FAIRLY RAPIDLY. ON DEP, WE MAINTAINED 3000 FT AND WERE ADVISED BY DEP THAT WE WERE TO MAINTAIN 2000 FT. THE TWR AND CTR WERE CALLED TO VERIFY WHEN OUR CLRNC CHANGED TO 2000 FT. THEY ADVISED WHEN WE WERE GIVEN TFC INFO ON TKOF THE NEW ALT WAS GIVEN. IT IS APPARENT THAT THE CLRNC WAS NOT CLRLY UNDERSTOOD BY BOTH PLTS. WHEN RAPID AND MULTIPLE INSTRUCTIONS ARE GIVEN BY ATC AT TKOF, ALL AMBIGUITY MUST BE VERIFIED. IT WOULD HELP IF TA'S AND ACTUAL CLRNCS ARE SEPARATE XMISSIONS WHEN WORKLOAD IS HIGH IN THE AUTOMATED COCKPIT.

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.