Narrative:

A cessna was on short final; in the traffic pattern; when an airport vehicle asked to proceed onto runway 27R for a paint inspection. After the aircraft landed I cautioned the airport vehicle about the aircraft and told him to proceed onto runway 27R. I observed the airport vehicle proceed onto; and drives down the runway; east-to-west while the cessna started his departure roll. At about the same time a BE36; who had been doing touch and goes on runway 33; requested to land full stop on 27R for fuel. By the time the cessna was on crosswind; the BE36 was departing runway 33 and I told him to follow the cessna. I then observed the airport vehicle nearing the end of the runway and I; unwisely; assumed he would clear. I cleared the cessna for a short approach and the option and then cleared the BE36 to follow the traffic and cleared to land. I then observed the airport vehicle make a 180 and proceed back west-to-east on the runway; something he did not request or advise me of. By this time the cessna was on close in right base and I was about to send him around but it appeared the airport vehicle was heading towards taxiway P to clear the runway. It appeared to me that the airport vehicle was clear of the runway when the cessna crossed the landing threshold. Later in a phone discussion with the airport vehicle; he indicated he was stopping to take a picture; again something he did not advise of at the time of the inspection; when he observed the cessna and it appeared the cessna was on the runway at the same time as he was. He immediately cleared at taxiway P and a few seconds later observed the cessna pass by him on the upwind. A contributing factor was the fact that a maintenance person was in the tower cab trying to coordinate repair of the wind equipment; using their cell phone to talk to a co-worker at the sensors; adding to the noise level of the cab. Recommendation; I should not have assumed the airport vehicle was going to clear the runway. Furthermore there was no traffic for runway 27L and I could have easily put one or both cessna's on that runway but I didn't. At the same time the airport vehicle needs to be more forthcoming on what he really needs to do on the runway. If he's going to need to stop or turn around and take longer than a standard runway inspection then he needs to advise us.

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Original NASA ASRS Text

Title: OAK Controller described a near loss of separation event between an airport vehicle and a Cessna in the pattern resulting unclear communications between the Tower and the airport vehicle.

Narrative: A Cessna was on short final; in the traffic pattern; when an airport vehicle asked to proceed onto Runway 27R for a paint inspection. After the aircraft landed I cautioned the airport vehicle about the aircraft and told him to proceed onto Runway 27R. I observed the airport vehicle proceed onto; and drives down the runway; east-to-west while the Cessna started his departure roll. At about the same time a BE36; who had been doing touch and goes on Runway 33; requested to land full stop on 27R for fuel. By the time the Cessna was on crosswind; the BE36 was departing Runway 33 and I told him to follow the Cessna. I then observed the airport vehicle nearing the end of the runway and I; unwisely; assumed he would clear. I cleared the Cessna for a short approach and the option and then cleared the BE36 to follow the traffic and cleared to land. I then observed the airport vehicle make a 180 and proceed back west-to-east on the runway; something he did not request or advise me of. By this time the Cessna was on close in right base and I was about to send him around but it appeared the airport vehicle was heading towards Taxiway P to clear the runway. It appeared to me that the airport vehicle was clear of the runway when the Cessna crossed the landing threshold. Later in a phone discussion with the airport vehicle; he indicated he was stopping to take a picture; again something he did not advise of at the time of the inspection; when he observed the Cessna and it appeared the Cessna was on the runway at the same time as he was. He immediately cleared at Taxiway P and a few seconds later observed the Cessna pass by him on the upwind. A contributing factor was the fact that a Maintenance person was in the Tower Cab trying to coordinate repair of the wind equipment; using their cell phone to talk to a co-worker at the sensors; adding to the noise level of the cab. Recommendation; I should not have assumed the airport vehicle was going to clear the runway. Furthermore there was no traffic for Runway 27L and I could have easily put one or both Cessna's on that runway but I didn't. At the same time the airport vehicle needs to be more forthcoming on what he really needs to do on the runway. If he's going to need to stop or turn around and take longer than a standard runway inspection then he needs to advise us.

Data retrieved from NASA's ASRS site as of April 2012 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.