An Air Carrier flight crew entered an incorrect route in the FMS and failed to discover it prior to a track deviation.
Synopsis
An Air Carrier flight crew entered an incorrect route in the FMS and failed to discover it prior to a track deviation.
Narrative
The whole event started out by the fact that I programmed the FMC wrong while in cockpit preparation phase of the flight. Instead of putting ABCCBD01 in the route page; I put ABCCDB01. This programmed the FMC to SNA instead of SAN. Both routes have the same departure procedure of the BOACH2. Both pilots briefed what they were supposed to brief and went through the correct procedures on the ground. However; it was missed and it shouldn't have. The routes were very similar and we did not go through the entire route. We only looked at the first few fixes instead of the whole route. This made us turn in flight to HEC instead of TNP. I made a typing error on the FMC and some how; both of us missed the mistake by not looking at the entire route. They looked so alike that I did not catch it. I believe I made this mistake because I was fatigued. I had not received much sleep the night before because of being rerouted. I was waiting for 5 hours in another airport before even starting my day. This was the only way for Scheduling to catch me up with my original pairing. I knew I was tired; but at the time I did not think I was unable to perform my duties. I felt I made this simple mistake because of that. I should have called in fatigued but the pressure of the operation and time frame of the last round trip being so short prevented me from doing so. I felt tired but did not think that fatigue was hindering my job. In this case it was a big factor in making the mistake in programming the FMC.
Second reporter narrative
This sequence of events falls under the 'that will never happen to me' category; but it did! ... This was the last day of a three-day pairing and I was flying with the third First Officer assigned to the pairing. ... The only answer is that we need to slow down and pay attention to every detail and follow the guidance spelled out so well in the FOM. During times of operational pressure we must remind ourselves to actually slow down and remember that SAFETY is our greatest concern.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.