Date: 201405
Local time of day: 1801-2400
Location: BJC.Airport, CO
Aircraft: Small Aircraft; High Wing; 1 Eng; Fixed Gear
Operator: Personal
Operating under: Part 91
Flight phase: Initial Approach
Airspace: Class D BJC
ATC / advisory: Tower BJC
Second aircraft: Small Transport; Low Wing; 2 Recip Eng
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Confusion; Distraction; Situational Awareness; Troubleshooting; Workload
Anomaly: ATC Issue All Types; Airspace Violation All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Air Traffic Control Separated Traffic
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

Narrative: After resolving a tight opposite direction squeeze play; I breathed a sigh of relief and observed a VFR target approximately 5 miles northwest of the airport; indicating altitude 065. I heard a clicking or static in my ear like a pilot trying to transmit and made a call in the blind to see if an aircraft was on frequency inbound from the north or northwest. Meantime; I had cleared Aircraft Y for takeoff and had approved a northbound turn; potentially putting them in conflict with the unidentified inbound. Realizing this; I instructed Aircraft Y to fly runway heading and called the traffic. Finally; Aircraft X checked in; claiming they were 8 miles out - but in reality 3 miles out; having entered D airspace without clearance (I believe the full call sign might be Aircraft X; based at a nearby flight school to the north). I instructed her to enter a right downwind. I then observed the aircraft appeared to be heading right for the upwind traffic and firmly instructed the pilot to turn left and fly the downwind; also issuing a traffic advisory to her. Aircraft X appeared to be flying a very low; tight pattern as they turned downwind and I became curious if the pilot was familiar with the local airport or pattern (there was also virga in the vicinity of the airport; and they might have had difficulty seeing the airport or fighting downdrafts). As Aircraft X became established on downwind; I approved Aircraft Y to proceed on course. Based on the pilot's maneuvers; poor radio procedures; and bad readbacks; I decided the best course of action was to focus on Aircraft X and get her on the ground ASAP. To accomplish this; I had Aircraft Z (VFR practice approach) execute their missed approach turn earlier than usual to ensure they did not become a factor with Aircraft X. After landing; I instructed the pilot to make the turn on G Taxiway and contact Ground Control. I reminded the pilot a call sign was required for many readbacks; and heard her acknowledge (but also without a call sign again). I began to back taxi the next departure onto Runway 29L and then heard Ground Control make a request. Ground Control asked me to tell Aircraft X to stop and contact Ground Control; and I observed that it appeared she taxied on G without a clearance; crossing the hold bars for closed Runway 29R. I instructed the pilot to 'stop and contact Ground'; and I heard an acknowledgment. As the aircraft taxied in; I could overhear Ground Control also encountering difficulties getting the pilot to understand the route and read it back correctly.While safety was not imminently affected (Aircraft X and Aircraft Y passed well clear of each other); it appeared the pilot on the radios was not well prepared for flying in controlled airspace. While she exhibited some familiarity with procedures at times (such as providing an ATIS code); she entered the airspace without a clearance and did not seem to understand that ATC needs correct readbacks with a call sign. Though I try to be as accommodating as possible with student pilots who may be nervous on the radios; I am not convinced that this pilot was properly prepared to fly solo in controlled airspace (or if the instructor was on board; they should have intervened!) In hindsight; I was glad I made the call early on to keep the other aircraft (Aircraft Y and Aircraft Z) well clear of the inbound aircraft due to the communication difficulties.




Synopsis: Local Controller describes situation where a new pilot causes problems flying into the airport and then taxiing to the ramp.