Cessna 500 altitude misunderstanding with controller 1000 ft deviation near myf.

Attributes
ACN	454370
Time
Date	199911
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : myf.airport
State Reference	CA
Altitude	msl single value : 2800
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sct.tracon
Operator	common carrier : air carrier
Make Model Name	Citation I
Operating Under FAR Part	Part 91
Flight Phase	descent : approach descent : intermediate altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp pilot : multi engine
Experience	flight time last 90 days : 75 flight time total : 8000 flight time type : 3000
ASRS Report	454370
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp pilot : multi engine
Experience	flight time last 90 days : 80 flight time total : 7500 flight time type : 2900
ASRS Report	454371
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far non adherence other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : returned to assigned altitude none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

As PNF, I was handling the communications. The controller was extremely busy and there were occasions when people were stepping on each other. The controller assigned us what we heard as 2800 ft and with urgency in his voice told us to expedite the descent. As is our SOP, I entered 2800 ft on the altitude alerter and the captain repeated the altitude vocally. We went to flight idle and used speed brakes for the descent. When we were level at 2800 ft the controller informed us we had been cleared to 3800 ft. Replied that we had heard and I had read back 2800 ft.

Original NASA ASRS Text

Title: CESSNA 500 ALT MISUNDERSTANDING WITH CTLR 1000 FT DEV NEAR MYF.

Narrative: AS PNF, I WAS HANDLING THE COMS. THE CTLR WAS EXTREMELY BUSY AND THERE WERE OCCASIONS WHEN PEOPLE WERE STEPPING ON EACH OTHER. THE CTLR ASSIGNED US WHAT WE HEARD AS 2800 FT AND WITH URGENCY IN HIS VOICE TOLD US TO EXPEDITE THE DSCNT. AS IS OUR SOP, I ENTERED 2800 FT ON THE ALT ALERTER AND THE CAPT REPEATED THE ALT VOCALLY. WE WENT TO FLT IDLE AND USED SPD BRAKES FOR THE DSCNT. WHEN WE WERE LEVEL AT 2800 FT THE CTLR INFORMED US WE HAD BEEN CLRED TO 3800 FT. REPLIED THAT WE HAD HEARD AND I HAD READ BACK 2800 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.