Narrative:

I was assigned to work local control/ground control combined position, which is not uncommon at our control tower when traffic volume is light. An airport vehicle was out on runway 36 with a crew pulling weeds. The runway was not officially closed. Runway 31 was the advertised active runway. There were patches of ground fog obscuring portions of the airport surface although we were VFR. At some point, a fog bank came over the northern end of runway 36 and covered the vehicle and ground crew. Cpr X called for taxi and I took him to runway 36 thinking that it would expedite traffic and keep him away from operations on runway 31. When cpr X called ready on tower frequency, I cleared him for takeoff on runway 36. I first became aware of the operational error when the pilot asked me if I was aware that a truck was on the runway. Here are what I believe were the contributing factors: I failed to include a thorough scan of my notepad with my scan of the runway. The men working on the runway only had a radio in the truck. They could not respond to hearing me taxi the aircraft, nor to my clearing him for takeoff. I had gotten used to seeing the vehicle out the window and did not take special note that it might disappear in the fog. Unusual operations and requests from pilots operating on runway 31 diverted my attention from other operations on the field. Sunlight, falling on our blinking airport operations light, washed out the light and didn't catch my eye. Supplemental information from acn 222950: I was PIC of cpr X. We received clearance to taxi to runway 36. After completing our pre-takeoff checklists, we were cleared by the tower to 'taxi into position and hold.' we held in position for about 1 1/2 mins due to traffic on runway 31. The tower cleared us for takeoff and I began a normal takeoff. After rotating the aircraft and raising the gear, both the copilot and I saw a truck on the runway. I estimate we passed over top of the truck by 50 to 100 ft. The WX was clear and, although there was some patchy ground fog, it was not a factor in this incident. The slope of the runway and the truck's location made it difficult, if not impossible, to see the vehicle until rotation. The truck's location precluded a problem as a normal takeoff would pass well above this point. We received no indication of any obstruction on or near the runway. Our taxi and takeoff clrncs were normal.

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Original NASA ASRS Text

Title: CPR X TKOF ON OCCUPIED RWY HAD LTSS FROM VEHICLE ON RWY. SYS ERROR.

Narrative: I WAS ASSIGNED TO WORK LCL CTL/GND CTL COMBINED POS, WHICH IS NOT UNCOMMON AT OUR CTL TWR WHEN TFC VOLUME IS LIGHT. AN ARPT VEHICLE WAS OUT ON RWY 36 WITH A CREW PULLING WEEDS. THE RWY WAS NOT OFFICIALLY CLOSED. RWY 31 WAS THE ADVERTISED ACTIVE RWY. THERE WERE PATCHES OF GND FOG OBSCURING PORTIONS OF THE ARPT SURFACE ALTHOUGH WE WERE VFR. AT SOME POINT, A FOG BANK CAME OVER THE NORTHERN END OF RWY 36 AND COVERED THE VEHICLE AND GND CREW. CPR X CALLED FOR TAXI AND I TOOK HIM TO RWY 36 THINKING THAT IT WOULD EXPEDITE TFC AND KEEP HIM AWAY FROM OPS ON RWY 31. WHEN CPR X CALLED READY ON TWR FREQ, I CLRED HIM FOR TKOF ON RWY 36. I FIRST BECAME AWARE OF THE OPERROR WHEN THE PLT ASKED ME IF I WAS AWARE THAT A TRUCK WAS ON THE RWY. HERE ARE WHAT I BELIEVE WERE THE CONTRIBUTING FACTORS: I FAILED TO INCLUDE A THOROUGH SCAN OF MY NOTEPAD WITH MY SCAN OF THE RWY. THE MEN WORKING ON THE RWY ONLY HAD A RADIO IN THE TRUCK. THEY COULD NOT RESPOND TO HEARING ME TAXI THE ACFT, NOR TO MY CLRING HIM FOR TKOF. I HAD GOTTEN USED TO SEEING THE VEHICLE OUT THE WINDOW AND DID NOT TAKE SPECIAL NOTE THAT IT MIGHT DISAPPEAR IN THE FOG. UNUSUAL OPS AND REQUESTS FROM PLTS OPERATING ON RWY 31 DIVERTED MY ATTN FROM OTHER OPS ON THE FIELD. SUNLIGHT, FALLING ON OUR BLINKING ARPT OPS LIGHT, WASHED OUT THE LIGHT AND DIDN'T CATCH MY EYE. SUPPLEMENTAL INFO FROM ACN 222950: I WAS PIC OF CPR X. WE RECEIVED CLRNC TO TAXI TO RWY 36. AFTER COMPLETING OUR PRE-TKOF CHKLISTS, WE WERE CLRED BY THE TWR TO 'TAXI INTO POS AND HOLD.' WE HELD IN POS FOR ABOUT 1 1/2 MINS DUE TO TFC ON RWY 31. THE TWR CLRED US FOR TKOF AND I BEGAN A NORMAL TKOF. AFTER ROTATING THE ACFT AND RAISING THE GEAR, BOTH THE COPLT AND I SAW A TRUCK ON THE RWY. I ESTIMATE WE PASSED OVER TOP OF THE TRUCK BY 50 TO 100 FT. THE WX WAS CLR AND, ALTHOUGH THERE WAS SOME PATCHY GND FOG, IT WAS NOT A FACTOR IN THIS INCIDENT. THE SLOPE OF THE RWY AND THE TRUCK'S LOCATION MADE IT DIFFICULT, IF NOT IMPOSSIBLE, TO SEE THE VEHICLE UNTIL ROTATION. THE TRUCK'S LOCATION PRECLUDED A PROB AS A NORMAL TKOF WOULD PASS WELL ABOVE THIS POINT. WE RECEIVED NO INDICATION OF ANY OBSTRUCTION ON OR NEAR THE RWY. OUR TAXI AND TKOF CLRNCS WERE NORMAL.

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.