B737 crew took off with no tower clearance. The crew thought the tower was closed.

Attributes
ACN	622376
Time
Date	200312
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : gpt.airport
State Reference	MS
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tower : tpa.tower
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : taxi ground : takeoff roll ground : pushback
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 148 flight time total : 6400 flight time type : 2750
ASRS Report	622376
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 159 flight time total : 19000 flight time type : 4300
ASRS Report	622377
Events
Anomaly	incursion : runway non adherence : published procedure non adherence : far
Independent Detector	other controllera
Resolutory Action	controller : issued advisory none taken : anomaly accepted
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Company
Air Traffic Incident	Pilot Deviation

Narrative:

Preflight checks in progress, we picked up IFR clearance on 120.4. Controller gave 'cleared as filed, maintain 2000 ft.' preflight checks completed and cabin secured for push. We called 120.4 for push and start. No reply. After repeated attempts we tried (123.7) with same results. Attempts on communication #2 were the same -- no reply. We knew the radio worked because we had just talked on the company frequency. Captain noticed 10-7 page showed no tower operations from XA00. We figure that explains the silence from ground/tower calls. We then reverted to uncontrolled airport procedures. Pushback was on our own (facing the tower). We could southeast that there was someone in the tower, but figured they were just setting up to open at XB00. After starting and disconnecting, clearing ground crew away, I called over CTAF, 'air carrier X taxiing from airline ramp to runway 14.' all normal checks complete and ready for takeoff, I announced over CTAF, 'air carrier taking active runway 14 for departure to the west.' no reply was ever heard from an ATC facility or any other traffic in area. Captain performed normal takeoff. Passing about 1200 ft MSL we tried one more call on 123.7 before calling ZHU on 127.65. This time, controller answered and informed us we took off without a clearance. We explained reasons for our actions, no reply from controller, and left it at that.

Original NASA ASRS Text

Title: B737 CREW TOOK OFF WITH NO TWR CLRNC. THE CREW THOUGHT THE TWR WAS CLOSED.

Narrative: PREFLT CHKS IN PROGRESS, WE PICKED UP IFR CLRNC ON 120.4. CTLR GAVE 'CLRED AS FILED, MAINTAIN 2000 FT.' PREFLT CHKS COMPLETED AND CABIN SECURED FOR PUSH. WE CALLED 120.4 FOR PUSH AND START. NO REPLY. AFTER REPEATED ATTEMPTS WE TRIED (123.7) WITH SAME RESULTS. ATTEMPTS ON COM #2 WERE THE SAME -- NO REPLY. WE KNEW THE RADIO WORKED BECAUSE WE HAD JUST TALKED ON THE COMPANY FREQ. CAPT NOTICED 10-7 PAGE SHOWED NO TWR OPS FROM XA00. WE FIGURE THAT EXPLAINS THE SILENCE FROM GND/TWR CALLS. WE THEN REVERTED TO UNCTLED ARPT PROCS. PUSHBACK WAS ON OUR OWN (FACING THE TWR). WE COULD SE THAT THERE WAS SOMEONE IN THE TWR, BUT FIGURED THEY WERE JUST SETTING UP TO OPEN AT XB00. AFTER STARTING AND DISCONNECTING, CLRING GND CREW AWAY, I CALLED OVER CTAF, 'ACR X TAXIING FROM AIRLINE RAMP TO RWY 14.' ALL NORMAL CHKS COMPLETE AND READY FOR TKOF, I ANNOUNCED OVER CTAF, 'ACR TAKING ACTIVE RWY 14 FOR DEP TO THE W.' NO REPLY WAS EVER HEARD FROM AN ATC FACILITY OR ANY OTHER TFC IN AREA. CAPT PERFORMED NORMAL TKOF. PASSING ABOUT 1200 FT MSL WE TRIED ONE MORE CALL ON 123.7 BEFORE CALLING ZHU ON 127.65. THIS TIME, CTLR ANSWERED AND INFORMED US WE TOOK OFF WITHOUT A CLRNC. WE EXPLAINED REASONS FOR OUR ACTIONS, NO REPLY FROM CTLR, AND LEFT IT AT THAT.

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.