A C550 flight crew descends below 6000 ft without permission while on a vector for a visual approach...

Attributes
ACN	349100
Time
Date	199609
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : vny
State Reference	CA
Altitude	msl bound lower : 4000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bur
Operator	common carrier : air taxi
Make Model Name	Citation II S2/Bravo
Operating Under FAR Part	Part 91
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 11870 flight time type : 4800
ASRS Report	349100
Person 2
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were ferrying the aircraft from sna to vny, setting up for a flight later that day. The captain was the PNF and the first officer was the PF. We were being radar vectored at 6000 ft. The controller said to expect the ILS runway 16R at vny, maintain 6000 ft. During this time I was getting the ATIS, reviewing the approach chart, setting up and briefing for the approach, and trying to contact the FBO at vny. The first officer said there is the airport at 1 O'clock. I told ATC that we had the airport. He said to expect the visual approach to runway 16R and maintain 6000 ft. I went back to requesting services with the FBO. My first awareness that something was wrong was when the controller said not to descend below 4000 ft. I said to the first officer we have not been cleared for the visual. He said he thought the controller said cleared for the visual. Shortly thereafter we were cleared for the visual. Looking back, I should not have devoted so much time to nonessential tasks. Also, I felt very comfortable with the first officer's flight skills. That led me into a false sense of security.

Original NASA ASRS Text

Title: A C550 FLC DSNDS BELOW 6000 FT WITHOUT PERMISSION WHILE ON A VECTOR FOR A VISUAL APCH.

Narrative: WE WERE FERRYING THE ACFT FROM SNA TO VNY, SETTING UP FOR A FLT LATER THAT DAY. THE CAPT WAS THE PNF AND THE FO WAS THE PF. WE WERE BEING RADAR VECTORED AT 6000 FT. THE CTLR SAID TO EXPECT THE ILS RWY 16R AT VNY, MAINTAIN 6000 FT. DURING THIS TIME I WAS GETTING THE ATIS, REVIEWING THE APCH CHART, SETTING UP AND BRIEFING FOR THE APCH, AND TRYING TO CONTACT THE FBO AT VNY. THE FO SAID THERE IS THE ARPT AT 1 O'CLOCK. I TOLD ATC THAT WE HAD THE ARPT. HE SAID TO EXPECT THE VISUAL APCH TO RWY 16R AND MAINTAIN 6000 FT. I WENT BACK TO REQUESTING SVCS WITH THE FBO. MY FIRST AWARENESS THAT SOMETHING WAS WRONG WAS WHEN THE CTLR SAID NOT TO DSND BELOW 4000 FT. I SAID TO THE FO WE HAVE NOT BEEN CLRED FOR THE VISUAL. HE SAID HE THOUGHT THE CTLR SAID CLRED FOR THE VISUAL. SHORTLY THEREAFTER WE WERE CLRED FOR THE VISUAL. LOOKING BACK, I SHOULD NOT HAVE DEVOTED SO MUCH TIME TO NONESSENTIAL TASKS. ALSO, I FELT VERY COMFORTABLE WITH THE FO'S FLT SKILLS. THAT LED ME INTO A FALSE SENSE OF SECURITY.

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.