Date: 201510
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Personal
Flight phase: Taxi
ATC / advisory: Tower ZZZ
Second aircraft: Regional Jet 200 ER/LR (CRJ200)
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Confusion; Communication Breakdown; Time Pressure
Second reporter function: Single Pilot
Anomaly: ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Detector: Person Flight Crew; Person Air Traffic Control
When detected: In-flight
Result: Flight Crew Took Evasive Action; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: Aircraft X was a VFR PA-28 inbound. Requested full stop taxi back; VFR departure. Aircraft was instructed to hold short of RWY 23 for landing traffic. A jet was cleared to land Runway 23. Aircraft X was given a VFR departure clearance to maintain VFR at or below 3;500 feet and the departure frequency. WITHOUT takeoff clearance [the aircraft] entered the active runway 23 and started takeoff roll while the jet was on short final. The jet was instructed to go around.A reiteration of hold short instructions to [the aircraft] may have helped to avoid this situation; but the aircraft had already read back hold short instructions once. The pilot of Aircraft X may have mistaken the VFR departure clearance for a takeoff clearance.


Second narrative: While I was holding short of runway 23; tower gave me my clearance to proceed on course to ZZZ; maintain VFR below 3;500 feet could be raised after departure; which I misinterpreted as a takeoff clearance; and the frequency for departure clearance. I switched to departure frequency as I turned onto the runway. Departure asked what altitude I was leaving. I told them I was still on the ground; and they told me to call tower. I replied that tower had given me my clearance and that I had called them at the wrong time. I looked over and saw the incoming plane; but since I thought I had the takeoff clearance I continued with takeoff. I went full throttle and took off while the other plane went over me; I saw it ahead of me as I was climbing. The other plane went around. Departure told me to proceed on course and asked me what altitude I wanted. I told them 4;500 feet and they gave me clearance to climb that high and told me to write down a phone number when I could. I proceeded on course; while climbing I was asked if I was ready for the number. I asked for another minute; climbed a bit more; then asked for and wrote down the phone number given to me. When I called after landing; the man on the phone explained the differences in clearances; then told me that tower was trying to tell me to stop; but I had already switched to departure. He also mentioned that according to the radar there were about 200 feet of distance between me and the local [jet] when he went around.


Synopsis: A Tower Controller instructed a PA28 pilot to hold short for landing traffic then issued departure instructions. The PA28 Pilot thought the departure instructions included takeoff clearance; switch frequencies and began the takeoff roll. ATC issued the landing jet go-around instructions over the PA28.