An A320 flight crew performing an air carrier's FMS transition starts a descent before being cleared...

Attributes
ACN	382019
Time
Date	199709
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : brv airport : iad
State Reference	VA
Altitude	msl bound lower : 7000 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : iad tower : den
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 12000 flight time type : 210
ASRS Report	382019
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	non adherence : published procedure non adherence : clearance non adherence : far other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Over brooke VOR, landing at iad, given clearance to proceed via or cleared for barin FMS transition. We understood the clearance to 'descend on' the FMS transition and reported out of 10000 ft. At approximately 8000 ft, controller stated he did not want us to descend and stopped us at 7000 ft. There was no conflict with other aircraft. The barin FMS transition 'plate' does not give any expect altitudes. All altitudes appear to be firm altitude restrs. There is a 'tiny' note at the bottom that does say do not descend unless cleared. This note needs to be more noticeable. We called dulles approach control on phone after landing. They said there have been numerous misunderstandings about when to descend on this procedure. Said they were in the process of changing the way they issue this clearance.

Original NASA ASRS Text

Title: AN A320 FLC PERFORMING AN ACR'S FMS TRANSITION STARTS A DSCNT BEFORE BEING CLRED.

Narrative: OVER BROOKE VOR, LNDG AT IAD, GIVEN CLRNC TO PROCEED VIA OR CLRED FOR BARIN FMS TRANSITION. WE UNDERSTOOD THE CLRNC TO 'DSND ON' THE FMS TRANSITION AND RPTED OUT OF 10000 FT. AT APPROX 8000 FT, CTLR STATED HE DID NOT WANT US TO DSND AND STOPPED US AT 7000 FT. THERE WAS NO CONFLICT WITH OTHER ACFT. THE BARIN FMS TRANSITION 'PLATE' DOES NOT GIVE ANY EXPECT ALTS. ALL ALTS APPEAR TO BE FIRM ALT RESTRS. THERE IS A 'TINY' NOTE AT THE BOTTOM THAT DOES SAY DO NOT DSND UNLESS CLRED. THIS NOTE NEEDS TO BE MORE NOTICEABLE. WE CALLED DULLES APCH CTL ON PHONE AFTER LNDG. THEY SAID THERE HAVE BEEN NUMEROUS MISUNDERSTANDINGS ABOUT WHEN TO DSND ON THIS PROC. SAID THEY WERE IN THE PROCESS OF CHANGING THE WAY THEY ISSUE THIS CLRNC.

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.