Small Transport
Communication Breakdown
Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR; Ground Incursion Runway
Flight Crew Took Evasive Action; Flight Crew Executed Go Around / Missed Approach
Human Factors; Airspace Structure
During heavy traffic with inbound and outbound traffic Aircraft X was on short final. Aircraft Y was in line with several other aircraft for a [Runway] 28 departure. Aircraft X was calling position inbound for [Runway] 28. When Aircraft Y was number one in line to depart; the aircraft advanced on to the Runway 28 without any radio traffic and departed. This caused Aircraft X to go missed to avoid a collision. Aircraft Y never responded to any radio traffic.
Event happened at Yampa Valley Colorado. Contributing factors were a weather pause for both incoming and outgoing traffic. As we were trying to take off Denver Center was trying to sequence arrivals and departures. The aircraft in front of us was cleared to take off by Denver Center. We were asked if we could take off and be airborne within 90 seconds due to an inbound aircraft. We had an aircraft in sight and believed that to be the aircraft which we were cleared in front of. Contributing factor was Pilot in command was on ATC frequency but not on CTAF frequency. First officer was on both frequencies; but VFR aircraft was not transmitting position in pattern. As we took the runway and began our takeoff roll; chatter on the CTAF frequency alerted us to the traffic conflict. First Officer began giving vectors to Pilot Flying to avoid possible conflict. Due to being on takeoff roll we did not have visual on conflict aircraft. After getting airborne and getting in a safe flight configuration we took a slight left turn to displace ourselves from the TCAS information. We did not receive an RA likely because we were too low.Situational Awareness of Pilot Flying was increased dramatically once on both frequencies. Both pilots were under the impression clearance to depart was given with the aircraft we had in view to be the called traffic.
Pilot and ground employee reported that an aircraft did not communicate their intentions on CTAF; taxied onto the runway and departed in front of an inbound aircraft causing that aircraft to go-around.