Date: 201908
Local time of day: 1201-1800
Location: TUL.Airport, OK
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class E TUL
ATC / advisory: TRACON TUL
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Confusion; Situational Awareness
Second reporter function: First Officer; Pilot Flying
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Contributing factors: Airspace Structure; Human Factors; Procedure
Primary problem: Procedure

Narrative: During preflight; the First Officer received the enroute clearance over the radio while I listened in. Our filed route was BARNS; IBAKE; ZZZZZ2 Arrival. Clearance Delivery did not mention that this was a reroute of any kind. It sounded exactly as Dispatch had filed for us. During climbout ATC assigned us direct BARNS as we fully expected. After a frequency change ATC asked if we were proceeding to BARNS and then spelled it phonetically 'Yankee; Alpha; Romeo; November; Sierra.' I responded 'Negative; Negative; we are proceeding direct BARNS: Bravo; Alpha; Romeo.....' We were then instructed to proceed direct YARNS; but then asked what our heading would be to IBAKE. I had to type in YARNS into the FMS; confirm; execute; confirm the aircraft turning right to this fix and then type in IBAKE to get the heading to display to that fix. Once I gave them the heading to IBAKE; ATC then cleared us direct IBAKE which was now a left turn. Off we went. I have to say; I don't blame Clearance Delivery or ATC for this confusion. It is beyond belief that the FAA would have two fixes so close together with only the first letter different between the two names 'BARNS' versus 'YARNS.' It is tailor made for completely unnecessary confusion in a noisy cockpit at 300 knots. We filed for BARNS yet it appears that Clearance Delivery and ATC were actually saying YARNS. FAA has two fixes in fairly close proximity to each other that are easily misunderstood as the other because only the first letter differentiates between them. FAA needs to change the name of one of these fixes.


Second narrative: We were filed route TUL BARNS IBAKE ZZZZZ2. At the gate in TUL we called for PDC. The Controller read us a clearance route YARNS IBAKE. Since the fixes of BARNS and YARNS sound similar we didn't catch the difference. The controller never stated there was a reroute or an amendment to the route. During the climb we were cleared to what we thought was BARNS. A few seconds later ATC questioned our heading. We said direct BARNS. ATC informed us direct YARNS and spelled it out. We promptly corrected our course and continued the flight as normal. This event occurred because of very similar sounding fixes in a close geographical area. This is also a route we have never flown out of TUL and were not familiar. Also the controller reading us the pre-departure clearance never told us of a reroute or an amended route. Having two fixes that sound familiar in a close geographic area can be easily confused. I suggest renaming one of the fixes. Also have ATC clearly state any amendments or reroutes to filed routes.


Synopsis: Air carrier flight crew reported a track heading deviation during departure from TUL due to confusion between similar sounding fix names BARNS and YARNS.