Date: 201603
Local time of day: 0601-1200
Location: MSP.Airport, MN
Light: Daylight
Aircraft: Medium Large Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZMP
ATC / advisory: Center ZMP
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Troubleshooting; Situational Awareness; Human-Machine Interface; Confusion; Distraction
Second reporter function: Captain; Pilot Not Flying
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
Contributing factors: Procedure; Human Factors
Primary problem: Human Factors

Narrative: The flight event started as a quick turn. We received the clearance 'As filed.' The Captain inserted the flight plan into the FMS. What he inserted was Zmbro6 ODI - KG72k - KG72M... I verified the route and agreed it was correct. I used the total distance to destination and time to cross check ourselves and everything was within regular limits. During our climb out shortly after ATC asked if we were deviating as there was weather. He replied negative that we are flying as filed. He then pulled out the release and read it to ATC with route page on the FMS pulled up as to verify what I was reading. As he was doing this we saw why we were being asked and realized the Fix entered KG72k was really filed as KG78K. He informed the controller that we had it now entered in the FMS and could accept direct which he then cleared us for and we continued on our way.We've all entered incorrect fixes before; but never in 5 years of flying commercially have I seen a fix one number off of another that was less than 20-30 degrees off and within about 10 miles of each other. This was an honest mistake on our part but if these fixes aren't changed to be less similar from each other in sure this will happen again. KG72K and KG78K should be hundreds or thousands of miles apart; not practically on the same airway as each other.


Second narrative: I would like to start off by saying that I have never seen nor used these type of fixes. Also I have never received any memos nor training in regards to their existence. To be truthful I've asked several other pilots about them and unless they've flown this route also they have no idea of their existence. That being said completely realize this is by no means an excuse to improper loading of the FMS. But it does tell you that I was not familiar and my frame of mind when I loaded the fixes. As you can plainly see from the details of what transpired during our flight the difference between what I loaded to what was actually filed is surprisingly close. Also to my surprise they are not what you would consider geographically located far apart from each other at all. Normally if a fix is misspelled in loading or even misloaded into the FMS it is very obvious. There will be a change in route direction and or usually a large change in total mileage of the flight. This was not the case with the error I made. We followed SOPs by briefing the FO with our flight plan in the FMS as we each reviewed the release. However I would have to guess our eyes were playing tricks on us as it wasn't that dissimilar from what should have been loaded. Even after discussing it with my FO we were amazed as we looked right at it and because of its likeness the mistake wasn't caught.


Synopsis: EMB-170 flight crew reported of two fixes that were similar in name and closer than they liked; causing a heading issue with ATC. Captain reported that he had never been trained in this type of fix naming and did not know what to look for to crosscheck it.