Commuter levels at 5000 ft but questioned by approach as they indicate 4500 ft.

Attributes
ACN	317690
Time
Date	199510
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : iad
State Reference	VA
Altitude	msl bound lower : 4500 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : iad tower : mfd
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp pilot : instrument
Experience	flight time last 90 days : 230 flight time total : 4700 flight time type : 3000
ASRS Report	317690
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot
Independent Detector	other controllera
Resolutory Action	other other
Consequence	Other
Supplementary
Air Traffic Incident	Pilot Deviation

Narrative:

We descended to 5000 ft as assigned by wash dulles approach control. The controller asked us what our altitude was and my first officer told him that we were level at 5000 ft. He then said that he showed us out of 4500 ft and asked us again what our altitude was. My first officer again told him that we were level at 5000 ft. He did not say anything else about it and we never asked. I am writing this report just to document what had taken place.

Original NASA ASRS Text

Title: COMMUTER LEVELS AT 5000 FT BUT QUESTIONED BY APCH AS THEY INDICATE 4500 FT.

Narrative: WE DSNDED TO 5000 FT AS ASSIGNED BY WASH DULLES APCH CTL. THE CTLR ASKED US WHAT OUR ALT WAS AND MY FO TOLD HIM THAT WE WERE LEVEL AT 5000 FT. HE THEN SAID THAT HE SHOWED US OUT OF 4500 FT AND ASKED US AGAIN WHAT OUR ALT WAS. MY FO AGAIN TOLD HIM THAT WE WERE LEVEL AT 5000 FT. HE DID NOT SAY ANYTHING ELSE ABOUT IT AND WE NEVER ASKED. I AM WRITING THIS RPT JUST TO DOCUMENT WHAT HAD TAKEN PLACE.

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.