Date: 201502
Local time of day: 1801-2400
Location: BFI.Airport, WA
Aircraft: Small Aircraft
Flight plan: VFR
Flight phase: Takeoff / Launch
ATC / advisory: Tower BFI
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Distraction
Second reporter function: Flight Data / Clearance Delivery; Ground
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Detector: Person Flight Crew
When detected: Taxi
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Human Factors; Procedure
Primary problem: Procedure

Narrative: I was working Local West and Local East combined. Ground Control/Flight Data was combined with CIC. Local Assist was staffed. Traffic levels were very low. City vehicle called from B10 (south end of RWY 13R) to proceed north on the runway for a routine inspection. I cleared city vehicle to proceed north on RWY 13R. I then returned to a conversation with Flight Data controller referencing an interesting aircraft at an FBO ramp.Sometime later; I estimate 1 minute; Aircraft X called ready for a (west) departure from RWY 13R full length. I did a cursory scan of 13R; as I usually do; then cleared him for takeoff. A few moments later Aircraft X said 'Tower there's a vehicle on the runway!' I scanned and observed Aircraft X in position; but not moving and city vehicle northbound; almost to B3 (approximately 3;000 feet from Aircraft X). I immediately instructed city vehicle to exit the runway at B3; which he was already rapidly doing. I immediately informed the CIC of the error then re-scanned RWY 13R and again cleared Aircraft X for takeoff. At which point Aircraft X departed without further incident. During this incident Aircraft X had never started a takeoff roll. After the aircraft departed I realized that I had never activated the RID (Runway Incursion Device) for RWY 13R. Our policy clearly states to do so. I don't have any recommendations per say. But I do know that from now on I will always use the RID when I have a vehicle on the runway. Additionally I will use our 'high chair'; which allows scanning the middle portion of the runaway. It is very difficult to do so in the lower; more comfortable chairs that we usually use. During my 1st scan of the runway I was unable to see the middle portion or the runway due to tower cab equipment. This is a hot spot if you sit low. And a very poor practice to fall into; just sitting back; not standing to check the blind spot; which I estimate is exactly where city vehicle was when I cleared Aircraft X.


Second narrative: I was working at the Flight Data/Clearance Delivery/Ground Control function at the Flight Data position. I observed city vehicle enter RWY 13R; from B10 and proceed northbound. Next I heard Local West (LCW) say something that caused me to scan the runway for city vehicle. I observed city vehicle exiting runway 13R at B3 and Aircraft X that appeared to be in position and hold at A1. LCW told me that he had cleared Aircraft X for take-off and with city vehicle on the runway (I don't recall the exact words). He also said he did not use the RID (Runway Incursion Device). After city vehicle exited runway 13R; LCW cleared Aircraft X for takeoff. Only after city vehicle was off the runway and Aircraft X was re-cleared for takeoff did Aircraft X begin his takeoff roll.Before the incident we had been discussing an aircraft at a FBO. Traffic was light and I briefly; looked away and did not observe city vehicle; between mid-runway and B3. I did not notice that LCW had not activated the RID for the runway inspection. I did not hear LCW clear Aircraft X for takeoff. I will make it a personal goal to ensure the RID is activated; whenever I am aware of a vehicle on the runway; no matter what position I am working. I will also strive to limit my non-essential conversation; whenever vehicles are on an open runway.


Synopsis: BFI controllers described a runway incursion involving a departing cleared for takeoff small aircraft and a vehicle that was already approved to be on the runway. The Controller did not use the RID (Runway Incursion Device) when he allowed the vehicle onto the runway. Pilot advised Tower of traffic on runway; Controller removed the vehicle off the runway and the aircraft departed.