Date: 201407
Local time of day: 1801-2400
Location: BIL.Airport, MT
Light: Dusk
Aircraft: Small Transport; Low Wing; 2 Turboprop Eng
Operator: Air Taxi
Operating under: Part 121
Flight plan: VFR
Mission: Passenger
Flight phase: Landing
Airspace: Class C BIL
ATC / advisory: Tower BIL
Second aircraft: Medium Transport; Low Wing; 2 Turbojet Eng
Reporter organization: Government
Reporter function: Supervisor / CIC
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Distraction; Situational Awareness; Confusion
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance
Contributing factors: Company Policy; Airport; Procedure
Primary problem: Procedure

Narrative: The airport had issued a NOTAM and closed the main runway (28R/10L) to GA aircraft [for 2 hours] for asphalt repair and mowing.  During the closure the secondary runways were available and being used.  The asphalt repair had been completed and the airport vehicles escorting the repair crew exited the runway and reported clear of the runway.  Following their exit; the only remaining vehicles operating were the two mowers working in the runway safety area.  The Controller (CPC) working the Local Control (LC) position offered the main runway to the next arrival; Aircraft X; knowing that the repair crew was off the main runway and the second arrival; Aircraft Y would require the use of the main runway.  As Aircraft X was turning base to final; the mower asked if they should clear the runway safety area.  The CPC on LC questioned the need for the mower to move because Aircraft X is not an air carrier operator.  The mower operators stated they were not allowed to work in the safety area without ATC permission.  They also stated they were not comfortable being in the safety area with the arrival on short final and moved to the south outside of the safety area.  The mowers remained clear of the safety area while Aircraft X and Aircraft Y landed and Aircraft Z departed.  Following the last operation I took over at the LC position and asked the mower operators if they wanted the runway to remain closed for the remaining 25 minutes or if they would prefer a clearance in and out of the runway safety area.  They requested that the runway continue to be closed to finish mowing.  The main runway was not used for the remaining time of the NOTAM and all other traffic used the secondary runways.  The runway was re-opened when the mowing was complete. The first recommendation would be to correct the wording for the issued NOTAM.  The intention for the NOTAM was to make the runway available only to Aircraft Y; a scheduled air carrier arrival.  However; the NOTAM stated the runway was closed to GA aircraft.  This gave the appearance to both air taxi and air carrier operators that the runway would still be available for their use.  This created confusion between the airport; controllers; and pilots. The second recommendation would be for the airport to change its policy and operate in a manner consistent with CERT ALERT NO. 03-07 issued 11/12/03 and with FAAO 7110.65 3-1-5 and 3-1-6.  The current policy is for the airport to receive ATC approval to enter and operate within the runway safety area only when no operations are present on the runway.  This creates several issues with the CPC working the LC position.  It requires the controller to provide a movement area type clearance in a non-movement area where it is not needed.  The controller then has to continuously monitor this operation in the non-movement area to provide timely exiting instructions for a runway operation.  This creates additional and unnecessary work load and multiple transmissions for the controller.  The responsibility to monitor the Tower position and operate in the non-movement portion of the runway safety area belongs to the operator not the controller working the LC position.  ATC is only required to provide access to the non-movement runway safety areas and provide advisories and traffic information.  Done correctly this will reduce the transmissions and workload for these operations and allow the controller to focus on higher priority items while working LC.




Synopsis: BIL FLM describes situation where controllers were unsure if they should move mowers that were operating close to the runway.