A B737 crew reported that they manually entered and verified an alphanumeric flight plan routing after it did not automatically load. Because of a quick turn around; a transposition error in a waypoint entry was not seen and an enroute track deviation resulted.
Synopsis
A B737 crew reported that they manually entered and verified an alphanumeric flight plan routing after it did not automatically load. Because of a quick turn around; a transposition error in a waypoint entry was not seen and an enroute track deviation resulted.
Narrative
Aircraft deviated from ATC route by flying toward incorrect waypoint that was entered in error. FMS did not autoload and was manually loaded by First Officer. I read back both the route and legs from the FMS while the First Officer compared to the flight plan. After passing an enroute waypoint correctly; the aircraft flew to the next waypoint in the FMS: KDXYU. Approximately 10 minutes later; Center asked us to verify we were going to KDYXU. The active waypoint was KDXYU and upon looking at the flight plan; the error was obvious. Controller stated we could go to either waypoint and we elected to go to the correct waypoint: KDYXU. No traffic conflicts were mentioned and the rest of the flight was uneventful. We didn't have a lot of time between flights and this also involved an aircraft change. Human error was introduced when the FMS didn't autoload and was not caught during route/leg verification. Dyslexia is live and well! More attention to detail was/is needed during the route/leg verification especially when the alpha/numeric waypoints are used.
Second reporter narrative
We had just come in late and had to enter an already boarded aircraft. The route; which normally automatically uploads; did not upload.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.