Small aircraft pilot taxies without clearance believing tower closed.

Attributes
ACN	276090
Time
Date	199406
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ipt
State Reference	PA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 40 flight time total : 630 flight time type : 10
ASRS Report	276090
Person 2
Affiliation	government : faa
Function	controller : ground
Qualification	controller : non radar
Events
Anomaly	non adherence : published procedure non adherence : far
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I have flown out of williamsport, PA, several times before, at early hours just before the tower opens. I was always under the assumption that the tower opened at XY00 local time. Someone even told me it was XY00 when I inquired. I started the airplane in time to hear a commuter's repeated calls for an IFR clearance, which led me to believe the tower was closed. So , I began to taxi and announced I was crossing runway 12/30 on CTAF. It was then that the tower controller stopped me and told me that the tower opened at XX30 local time. I taxied without a clearance and almost had a runway incursion. Callback conversation with reporter revealed the following information: reporter was called as he is a CFI and there was concern that he was not using or teaching the use of airport facilities directory. He acknowledged that he knew of an used the airport facilities directory but had asked the FSS personnel when the tower opened and was told XY00 am. He also asked the line person if the tower opened at XY00 and the response was 'as far as I know.' well, the line person is obviously not the person to ask. Reporter now knows he must check for himself.

Original NASA ASRS Text

Title: SMA PLT TAXIES WITHOUT CLRNC BELIEVING TWR CLOSED.

Narrative: I HAVE FLOWN OUT OF WILLIAMSPORT, PA, SEVERAL TIMES BEFORE, AT EARLY HRS JUST BEFORE THE TWR OPENS. I WAS ALWAYS UNDER THE ASSUMPTION THAT THE TWR OPENED AT XY00 LCL TIME. SOMEONE EVEN TOLD ME IT WAS XY00 WHEN I INQUIRED. I STARTED THE AIRPLANE IN TIME TO HEAR A COMMUTER'S REPEATED CALLS FOR AN IFR CLRNC, WHICH LED ME TO BELIEVE THE TWR WAS CLOSED. SO , I BEGAN TO TAXI AND ANNOUNCED I WAS XING RWY 12/30 ON CTAF. IT WAS THEN THAT THE TWR CTLR STOPPED ME AND TOLD ME THAT THE TWR OPENED AT XX30 LCL TIME. I TAXIED WITHOUT A CLRNC AND ALMOST HAD A RWY INCURSION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR WAS CALLED AS HE IS A CFI AND THERE WAS CONCERN THAT HE WAS NOT USING OR TEACHING THE USE OF ARPT FACILITIES DIRECTORY. HE ACKNOWLEDGED THAT HE KNEW OF AN USED THE ARPT FACILITIES DIRECTORY BUT HAD ASKED THE FSS PERSONNEL WHEN THE TWR OPENED AND WAS TOLD XY00 AM. HE ALSO ASKED THE LINE PERSON IF THE TWR OPENED AT XY00 AND THE RESPONSE WAS 'AS FAR AS I KNOW.' WELL, THE LINE PERSON IS OBVIOUSLY NOT THE PERSON TO ASK. RPTR NOW KNOWS HE MUST CHK FOR HIMSELF.

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.