PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Air Traffic Control Fully Certified
Air Traffic Control Non Radar 5
Situational Awareness; Confusion; Communication Breakdown; Time Pressure
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Flight Crew Took Evasive Action; Flight Crew Executed Go Around / Missed Approach
Human Factors; Procedure
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.
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.
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.