EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Aircraft; Human Factors
Flight operated as a normal scheduled flight. Since ORD has no RNAV departure procedures; all departure fixes must be entered into the FMS manually. We were filed and cleared via the ORD 8 departure EARND ELANR EMMLY ETAME. I typed in all of the fixes and then verified that they were all there by looking at the compressed flight plan page. The FO crossfilled from my FMS and then verified that all way points were entered. Flight departed normally and was climbing out on autopilot coupled to the FMS. Just south of EARND intersection; Center asked if we were flying to ETAME. We looked at the FMS and that was exactly what we were doing. Unnoticed by either of us; the FMS had dropped the waypoints of ELANR and EMMLY. We told Center what we had discovered and the controller recleared us direct to the point where we were actually going to. This controller did not seem surprised that points had dropped out and sadly; neither am I. The Universal FMS routinely drops data. Most times I catch it. This time I didn't.   As we all know; aircraft being off course can cause serious problems. I suspect that by the time everything was sorted out that our flight was over 8 miles east of where it should have been. Thankfully it was VFR and it appears to me that this has happened so many times that ATC possibly provides additional lateral separation. On this day; there was nobody around us. The purpose of autopilot coupled to FMS guidance is to reduce human navigational errors. When all standardized procedures are followed to trap data entry problems prior to ever leaving the ground and then there is still a lateral deviation; the focus must be placed on the automation. I am absolutely amazed that the Administrator still allows the Universal FMS to operate in the National Airspace System. It was outdated and obsolete over 20 years ago! Yet it is still in our aircraft. I have lost count of the number of times this unit has taken me on a wild goose chase and I have caught it. Each time that I have caught it; I tell the controllers that the FMS has done it again and I need a heading until I can get something in place to navigate by. These very controllers are neither surprised nor unwilling to give me what I need. Mister Administrator; there are other options available to bring the level of safety that air travel demands. These options however; cost more than the leaders in the airline world want to spend.
EMB-145LR Captain reported a track deviation because his Universal FMS dropped some points out of the route. Reporter stated this is a common occurrence.