EMB ERJ 145 ER/LR
Human-Machine Interface
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance; Flight Crew Became Reoriented
Company Policy; Human Factors; Procedure
While programming the FMS prior to departure; my Captain allowed me to input the routing for practice as I was very new and only on my second trip off IOE. My Captain watched as I input the flight plan to verify I was doing it correctly and to cross check it himself. However; I made a mistake and input a waypoint incorrectly. Along the routing there were two way points identified by a series of letters followed by numbers. For instance; KG1483 followed by KG1494. I believe it was the second waypoint that I entered incorrectly by simply inputting an incorrect number. I can not remember exactly what it was but it was something like KG1464 instead of KG1494. The incorrectly input waypoint did exist and did not alter the course very much so it appeared during the preflight routine; to be correct; and the mistake went undetected by both me and the Captain. In cruise when we reached the error in the flight plan the aircraft began tracking to the incorrect point. The course to the incorrect point was not much different than our normal course so the mistake went unnoticed. Very shortly after ATC caught the deviation and asked what point we were tacking to. We read told them the series of letters and numbers we were tracking to and they read back the correct waypoint which again differed by only one number I believe. After the clarification they subsequently cleared us to some point even further ahead on our flight plan. The threat was that we had an error in our FMS that neither of us were aware of and that neither of us were likely to detect without a very close examination of the routing on the flight plan; as the mistake was not obvious at a glance. The error was my incorrect input of the point into the FMS. Our undesired state that resulted was a small yet still undesired track of an incorrect course which ATC was not anticipating. In the future I must be more diligent and careful when inputting the flight plan; especially when way-points are very easy to overlook because they are just a series of letters and numbers. I'm not sure if the company could do anything better to avoid this problem in the future; maybe just put out a notice telling pilots to be careful of making the same mistake I did.
EMB145 First Officer reports errors made entering a flight plan composed of fixes designated by two letters and four numbers for each fix. Some of the numbers become transposed or entered in error resulting in a track deviation.