Date: 201904
Local time of day: 1201-1800
Location: BJC.Airport, CO
Flight conditions: VMC
Aircraft: Small Aircraft; High Wing; 1 Eng; Fixed Gear
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Personal
Flight phase: Landing
Airspace: Class D BJC
ATC / advisory: Tower BJC
Second aircraft: Small Aircraft; High Wing; 1 Eng; Fixed Gear
Reporter organization: Government
Reporter function: Supervisor / CIC
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Distraction
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Critical
Detector: Person Air Traffic Control; Person Flight Crew
When detected: Taxi
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: I was working CIC (Controller in Charge) and traffic was picking up; with multiple aircraft in the local pattern. I remember I just asked Local Control if they wanted to split off Local 2; and was getting the position ready in anticipation of making the split. Suddenly; I heard Local Control exclaim that they didn't have spacing on the runway; and saw a Cessna touching down with traffic taxiing on the runway ahead; approaching an intersection near midfield. I heard Local Control tell Aircraft Y to expedite to exit; and I thought I also heard the aircraft touching down (Aircraft X) say they were making a stop due to the traffic ahead. Aircraft Y exited without incident; and Aircraft X continued their pattern work after. Local Control recovered the position; and we then split the locals as soon as possible. It was a fast paced environment in the cab at the time; and I think Local Control and myself (as CIC) may have simply overlooked the traffic situation when the first aircraft did not keep their roll speed up; or exit as soon as expected for their full stop. Volume and complexity in the VFR tower environment can spike at a moment's notice. When the staffing is available and workload dictates; it makes good sense to have Local Controls split to balance the workload and provide better oversight of surface operations. A human can only track so many aircraft and scan so many surfaces in a set amount of time; and splitting the locals allows us to accomplish this in a better; safer way. Having the second Local Control open can help us catch sooner if runway spacing will not be sufficient; so we can issue a go around or runway exiting instructions more promptly. It can be a balancing act at times to try to combine and split positions in a timely manner as traffic dictates. I feel like the Watch Supervisor or CIC should try their best to coordinate with Local Control on how they are doing; and what they desire to do (split or stay combined). It can be important for controllers to work positions combined at times to maintain proficiency on their own. However; there are also times when Local Control may not realize they are starting to get overwhelmed with complexity and volume; and it may be necessary for watch supervision to become more assertive and simply direct Local Control to split the position; before they 'lose the picture.' We have to trust each other in the tower cab and realize that suggesting (or directing) someone to split positions should not be viewed as a reflection on a person's abilities; but it is to ensure we utilize our resources as best we can; in order to provide the safest; most efficient service possible to all users of the NAS.




Synopsis: BJC Tower Controller in Charge reported Local Control allowed an aircraft to land with a previous arriving aircraft still on the runway.