Pilot deviation. Descended without clearance.

Attributes
ACN	292840
Time
Date	199501
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : pdx
State Reference	OR
Altitude	msl bound lower : 8000 msl bound upper : 2500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : pdx artcc : zmp
Operator	other
Make Model Name	Gates Learjet Corp Undifferentiated or Other Model
Operating Under FAR Part	Part 135
Flight Phase	descent : approach descent other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 15500 flight time type : 5000
ASRS Report	292840
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : atp
Experience	flight time last 90 days : 120 flight time total : 15000 flight time type : 1000
ASRS Report	292941
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were in a lear jet (aircraft X) making a VFR approach to pdk airport on an instrument flight plan at 8000 ft MSL. We called airport in sight with ATIS information. We thought the approach controller told us we were cleared for the visual approach right traffic for runway 2R. We started a descent to pattern altitude 2500 ft MSL. When we were out of 3800 ft MSL, the controller asked us what altitude we were assigned. We advised him we thought we were cleared for the visual approach. He then informed us that he had said to expect a visual approach right traffic for runway 2R, so now to maintain 3000 ft MSL, which we did. My copilot and myself did not hear the word 'expect' and that is the reason we descended out of 8000 ft MSL.

Original NASA ASRS Text

Title: PLTDEV. DSNDED WITHOUT CLRNC.

Narrative: WE WERE IN A LEAR JET (ACFT X) MAKING A VFR APCH TO PDK ARPT ON AN INST FLT PLAN AT 8000 FT MSL. WE CALLED ARPT IN SIGHT WITH ATIS INFO. WE THOUGHT THE APCH CTLR TOLD US WE WERE CLRED FOR THE VISUAL APCH R TFC FOR RWY 2R. WE STARTED A DSCNT TO PATTERN ALT 2500 FT MSL. WHEN WE WERE OUT OF 3800 FT MSL, THE CTLR ASKED US WHAT ALT WE WERE ASSIGNED. WE ADVISED HIM WE THOUGHT WE WERE CLRED FOR THE VISUAL APCH. HE THEN INFORMED US THAT HE HAD SAID TO EXPECT A VISUAL APCH R TFC FOR RWY 2R, SO NOW TO MAINTAIN 3000 FT MSL, WHICH WE DID. MY COPLT AND MYSELF DID NOT HEAR THE WORD 'EXPECT' AND THAT IS THE REASON WE DSNDED OUT OF 8000 FT MSL.

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.