Captain reported mishearing the clearance altitude during departure from iad.

Attributes
ACN	515890
Time
Date	200106
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : iad.airport
State Reference	VA
Altitude	msl bound lower : 3000 msl bound upper : 3800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : iah.tower
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : n/s
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 8300 flight time type : 800
ASRS Report	515890
Events
Anomaly	altitude deviation : overshoot non adherence : far non adherence : company policies non adherence : clearance
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Other pilot set altitude as 5000 ft for climb. We had waited 2.5 hours for takeoff because of bad WX in new york area. Much of the time was in aircraft, on ramp, with passenger. On climb out, as we passed 3800 ft MSL, departure asked our altitude clearance. We said 5000 ft. She said it should have been 3000 ft and cleared us to 5000 ft. During the confusion and changes on the ramp, we misinterped the 3000 ft as a 5000 ft clearance.

Original NASA ASRS Text

Title: CAPT RPTED MISHEARING THE CLRNC ALT DURING DEP FROM IAD.

Narrative: OTHER PLT SET ALT AS 5000 FT FOR CLB. WE HAD WAITED 2.5 HRS FOR TKOF BECAUSE OF BAD WX IN NEW YORK AREA. MUCH OF THE TIME WAS IN ACFT, ON RAMP, WITH PAX. ON CLBOUT, AS WE PASSED 3800 FT MSL, DEP ASKED OUR ALT CLRNC. WE SAID 5000 FT. SHE SAID IT SHOULD HAVE BEEN 3000 FT AND CLRED US TO 5000 FT. DURING THE CONFUSION AND CHANGES ON THE RAMP, WE MISINTERPED THE 3000 FT AS A 5000 FT 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.