Medium Transport; Low Wing; 2 Turbojet Eng
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 75; Flight Crew Total 10200; Flight Crew Type 200
Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Air Traffic Control Provided Assistance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Human Factors; Procedure
The tower and ground facility were extremely congested. While holding short of the runway; next in line to depart; tower began to issue a new departure clearance to our aircraft. As soon as the new clearance was being transmitted the frequency was 'stepped over' by other aircraft. As the SIC (Second in Command) I was handling the communication from the aircraft and advised ATC I had only copied part of the clearance in the meantime the PIC (Pilot in Command) had taxied the aircraft forward partially onto the runway. I advised the PIC I had not received a takeoff clearance; we stopped the aircraft; clarified with ATC that we were not cleared for takeoff. We advised ATC of our position partially on the runway; and they issued a clearance to cross the runway and turn around. Shortly thereafter we departed and the rest of the flight was without incident.
Air Taxi First Officer; the pilot monitoring; reported Captain inadvertently taxied over hold short line without clearance at VNY airport.