Aircraft departure from mcn received confusing departure clearance from tower controller; ie 'depart...

Attributes
ACN	769644
Time
Date	200801
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mcn.airport
State Reference	GA
Altitude	agl single value : 0
Environment
Flight Conditions	IMC
Weather Elements	Fog
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Qualification	pilot : flight engineer pilot : cfi pilot : atp pilot : multi engine
Experience	flight time last 90 days : 150 flight time total : 28400 flight time type : 20000
ASRS Report	769644
Person 2
Affiliation	other
Function	controller : local
Events
Anomaly	non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	Airport ATC Human Performance Environmental Factor
Primary Problem	Ambiguous

Narrative:

Tower opens at XB00; I taxied out as XA55 to end of runway 23. Visibility was about 1/16; but being part 91 I was legal to depart IFR. I asked tower when they opened for clearance to ZZZ. Tower read me the IFR clearance; and when I said I was ready for takeoff they said that I was cleared to 'depart at your own risk.' I asked if that meant I was cleared for takeoff. Response was that they could not clear me for takeoff because they could not see the runway (I had never heard of such requirement) and because they did not have a runway check yet. (I would have thought this should have been done before tower opened; and there were several IFR departures before tower opened; given clearance by atl approach control. Apparently no runway check had been done for those departures. At macon; these checks are done by the fire department usually.) I assumed this meant that I was cleared to enter the class D and proceed as the IFR clearance allowed me to do. Once again I was told; 'depart at your own risk.' I took off; reported cloud tops; switched to departure control and proceeded. In 50 yrs of flying I had never heard such a restr on takeoff clearance.

Original NASA ASRS Text

Title: ACFT DEP FROM MCN RECEIVED CONFUSING DEP CLRNC FROM TWR CTLR; IE 'DEPART AT YOU OWN RISK;' IMMEDIATELY AFTER TWR OPENING.

Narrative: TWR OPENS AT XB00; I TAXIED OUT AS XA55 TO END OF RWY 23. VISIBILITY WAS ABOUT 1/16; BUT BEING PART 91 I WAS LEGAL TO DEPART IFR. I ASKED TWR WHEN THEY OPENED FOR CLRNC TO ZZZ. TWR READ ME THE IFR CLRNC; AND WHEN I SAID I WAS READY FOR TKOF THEY SAID THAT I WAS CLRED TO 'DEPART AT YOUR OWN RISK.' I ASKED IF THAT MEANT I WAS CLRED FOR TKOF. RESPONSE WAS THAT THEY COULD NOT CLR ME FOR TKOF BECAUSE THEY COULD NOT SEE THE RWY (I HAD NEVER HEARD OF SUCH REQUIREMENT) AND BECAUSE THEY DID NOT HAVE A RWY CHK YET. (I WOULD HAVE THOUGHT THIS SHOULD HAVE BEEN DONE BEFORE TWR OPENED; AND THERE WERE SEVERAL IFR DEPS BEFORE TWR OPENED; GIVEN CLRNC BY ATL APCH CTL. APPARENTLY NO RWY CHK HAD BEEN DONE FOR THOSE DEPS. AT MACON; THESE CHKS ARE DONE BY THE FIRE DEPT USUALLY.) I ASSUMED THIS MEANT THAT I WAS CLRED TO ENTER THE CLASS D AND PROCEED AS THE IFR CLRNC ALLOWED ME TO DO. ONCE AGAIN I WAS TOLD; 'DEPART AT YOUR OWN RISK.' I TOOK OFF; RPTED CLOUD TOPS; SWITCHED TO DEP CTL AND PROCEEDED. IN 50 YRS OF FLYING I HAD NEVER HEARD SUCH A RESTR ON TKOF CLRNC.

Data retrieved from NASA's ASRS site as of May 2009 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.

Aircraft departure from mcn received confusing departure clearance from tower controller; ie 'depart at you own risk;' immediately after tower opening.