M-20 R Ovation
Air Traffic Control Fully Certified
Communication Breakdown
ATC Issue All Types; Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Vehicle
General None Reported / Taken
Human Factors; Procedure
Mowers requested to go from area of F1 on Taxiway Foxtrot to cut around the lights of Runway 22L. Runway 4R was open and active runway but east of midfield our local vehicles always call the runway number as to which side they are on. I told the mower to proceed as requested and remain clear of all runways which she read back correctly. A Mooney called ready to depart VFR off Runway 4R and during clearance for takeoff I advised him of mowers on the right side near Taxiway Foxtrot. After the aircraft started his roll; I looked at the mowers and noticed the lead mower crossing Runway 4R at Foxtrot. I broadcast for the mower to stop and got no response; the second mower was in the safety area but not yet on the runway surface. The second mower stopped. I did not think that the departing aircraft could stop but told him about the mowers crossing. The aircraft went between the mowers and after climbout told me that he heard what I said and could not stop or he thought he would hit the mower. After questioning the mowers I told them that they were told to remain clear of all runways and she said she understood that but they were told the runway was closed. I informed her that the runway was not closed and verified that they would be remaining where they were and were not to cross any more runways. I then asked another mower who had been out in the same area if he had been advised that the runway was closed. He responded that there had been a runway closure [once a week] for a while and they had on their sheet indicated that 4R/22L was indeed closed today. I re-verified with him that the runway was not closed and to remain clear. I then checked the NOTAMs to see if maybe the closure was missed and there was no NOTAM listed for any runway closure today. Better communication between airport operators and the Tower about closures.
BTR Controller described an unauthorized runway entry by mowers due to confusion regarding runway closure status.