EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Situational Awareness
Conflict Ground Conflict; Critical; Ground Incursion Runway
Flight Crew Rejected Takeoff
Aircraft; Human Factors
Rejected takeoff. We saw the [transport aircraft] tail [not clear of the runway] and [the Captain] commanded the RTO. [Transport aircraft] tail not clear of runway despite commands to clear by ATC. The takeoff was rejected. We let brakes cool to 'green' range on MFD; taxied back for another takeoff. No further issues.
EMB-145 First Officer reported rejecting the takeoff when they realized another transport aircraft had not cleared the runway.