Date: 202012
Local time of day: 0001-0600
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch; Taxi
Airspace: Class G ZZZ1
ATC / advisory: CTAF ZZZ
Second aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Situational Awareness; Communication Breakdown
Anomaly: Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Aircraft
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors; Aircraft
Primary problem: Aircraft

Narrative: Everything during the preflight; engine start; and taxi out went normal. During the taxi out our clearance was picked up with a 5 minute void time. We had calm winds and [Runway] XX is the calm wind runway so we had briefed and planned for a [Runway] XX departure. There was work on the taxiway so it was going to require a back taxi to the end of [Runway] XX at an uncontrolled field. Coming out of the ramp we informed over the CTAF what our intentions were and taxied and held short of the runway. While holding short of the runway with some traffic in the pattern for [Runway] XX and a plane inbound on the GPS [Runway] XY doing a practice approach we realized we wouldn't get out in the 5 minutes. I put Center back in on Comm 1 and had my Captain on Comm 2 monitoring the CTAF. I asked Center for an extension explaining why we need it and they gave us another 10 minutes before the void time. I put the CTAF back on one and asked the Captain if I missed any important calls and he said no. We watched the plan in the pattern land [Runway] XX and I informed over the CTAF that we would hold short of the runway until the guy on GPS approach went missed and that we would then be back taxiing for full length takeoff on [Runway] XX. No one over the CTAF says anything else. We complete all checklists and are ready to go. After the GPS approach guy goes missed I inform over the CTAF that we are taking the runway and back taxiing on [Runway] XX. No one says anything. I looked right towards the [Runway] XX end and final and cleared that direction and the captain looked left towards the [Runway] XY end and final and cleared that direction. We then began our back taxi. During the back taxi I informed again over the CTAF that we were still back taxiing for a [Runway] XX departure. Nothing was said over the CTAF. We get to the end and line up for a full length departure. I inform over the CTAF that we are taking off [Runway] XX with a right turn out on the SID for a north departure. We wait a few seconds and nothing on the CTAF. We then began our takeoff roll with nothing out of the ordinary through 110ish kts. The runway was kinda of rounded and approaching V1 and cresting the rounded part of the runway I noticed something moving to the right of the runway. I said 'what's that?' Looked back down and it was V1 call out. At this time we realize it's an airplane that took off Runway XY and is making a left turn to our right. He was already a few hundred feet off the runway centerline and we were passed V1 so we continued with a normal departure sequence. During the departure we heard someone on the ground asking over the CTAF if the other plane had a radio. No response. It was asked a couple times with no response. We were asked by the person on the ground if we saw the plane. I was PM (Pilot Monitoring) so I responded with a yes and we asked for a radio check and were told that our radio was working. The other airplane finally responded saying he made at least 3 takeoff calls. The guys on the ground said that no calls were made from the other aircraft. He insisted again that he made the takeoff calls. Another plane flying just past the field who was on the CTAF also informed that he heard no takeoff calls from the other departing plane. We made a final call informing which direction our departure was and through what altitude we were climbing. Switched over to Center and had a standard flight the rest of the way. The cause was GA plane with a possible broken radio and or what seems to be more likely a wrong frequency tuned in was the biggest problem. If we had heard another plane wanting to takeoff in the opposite direction we would have never even started the back taxi let alone the takeoff. I'm not really sure what can be done about planes with no radios; broken radios; or wrong frequency's. We did everything to our power correctly and we were in no hurry with the extended void and were taking our time. Maybe operating even slower we could haveavoided being around the runway at the same time as this other plane. Hard to pin point something when everyone who was on frequency knew our intentions and what we were doing.




Synopsis: CRJ-200 First Officer reported an airborne conflict during takeoff with non-reporting aircraft opposite direction takeoff.