IFR BE200 departed cou without ATC release after tower closure.

Attributes
ACN	607194
Time
Date	200401
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : cou.airport
State Reference	MO
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : sgf.tracon
Operator	general aviation : corporate
Make Model Name	Super King Air 200 HDC
Operating Under FAR Part	Part 91
Flight Phase	climbout : takeoff ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 90 flight time total : 2800 flight time type : 500
ASRS Report	607194
Person 2
Function	observation : observer
Events
Anomaly	non adherence : clearance non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We departed cou airport after the tower had already closed. Before departure, we contacted cou FSS for current WX and local airport advisories (the WX was VFR and there was no other reported traffic). We then contacted mizzou approach for an IFR clearance on the ground. After receiving a clearance, we taxied out for departure, ran through our checklists, announced our intentions on CTAF and departed. When we contacted mizzou departure, we were told we were not released for departure and that this has happened many times with different aircraft at cou airport. When we received our clearance, we thought we were released because we don't remember being told to hold for release. This was an obvious miscom between us and the controller. The WX was VFR so there was no conflict with other aircraft. Had the WX been IFR, there is no doubt in my mind that we would have confirmed our release before departing as we always do. We should follow that practice in VFR conditions as well. Even though we both thought we had been released, it never hurts to doublechk, even in VFR.

Original NASA ASRS Text

Title: IFR BE200 DEPARTED COU WITHOUT ATC RELEASE AFTER TWR CLOSURE.

Narrative: WE DEPARTED COU ARPT AFTER THE TWR HAD ALREADY CLOSED. BEFORE DEP, WE CONTACTED COU FSS FOR CURRENT WX AND LCL ARPT ADVISORIES (THE WX WAS VFR AND THERE WAS NO OTHER RPTED TFC). WE THEN CONTACTED MIZZOU APCH FOR AN IFR CLRNC ON THE GND. AFTER RECEIVING A CLRNC, WE TAXIED OUT FOR DEP, RAN THROUGH OUR CHKLISTS, ANNOUNCED OUR INTENTIONS ON CTAF AND DEPARTED. WHEN WE CONTACTED MIZZOU DEP, WE WERE TOLD WE WERE NOT RELEASED FOR DEP AND THAT THIS HAS HAPPENED MANY TIMES WITH DIFFERENT ACFT AT COU ARPT. WHEN WE RECEIVED OUR CLRNC, WE THOUGHT WE WERE RELEASED BECAUSE WE DON'T REMEMBER BEING TOLD TO HOLD FOR RELEASE. THIS WAS AN OBVIOUS MISCOM BTWN US AND THE CTLR. THE WX WAS VFR SO THERE WAS NO CONFLICT WITH OTHER ACFT. HAD THE WX BEEN IFR, THERE IS NO DOUBT IN MY MIND THAT WE WOULD HAVE CONFIRMED OUR RELEASE BEFORE DEPARTING AS WE ALWAYS DO. WE SHOULD FOLLOW THAT PRACTICE IN VFR CONDITIONS AS WELL. EVEN THOUGH WE BOTH THOUGHT WE HAD BEEN RELEASED, IT NEVER HURTS TO DOUBLECHK, EVEN IN VFR.

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.