Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 100; Flight Crew Total 10000; Flight Crew Type 1200
Communication Breakdown; Human-Machine Interface
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Provided Assistance; Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem; Flight Crew Returned To Clearance; Flight Crew Requested ATC Assistance / Clarification
Airspace Structure; Human Factors; Procedure
[We were] initially given [our] departure PDC on ground. This is a SID for 26L/R only. Was re-cleared on ground to 19R [and depart via the SID] transition then AF. Upon reaching 19R; was told taxi across 19R and hold short 19L. Immediately reloaded departure runway and SID in FMS. Since the departure was already loaded; reloading the same SID with a different runway dropped off the transition and did not prompt the specific departure transition. We verified initial SID waypoints and were cleared for immediate takeoff. We experienced many altitude changes upon climb out and were given a heading off the SID for traffic. We were then given [a departure fix] with no specific rejoin the SID instruction. Since FMS dropped off the SID transition during the last minute runway change; we flew [ZZZ VOR] and missed the [two] transitional fixes. Center asked where we were going just after and we stated Flight planned route to [ZZZ VOR]. He noted direct [ZZZ VOR]. We then realized the FMS had dropped off [a fix and ZZZ VOR]. No traffic or airspace incursions were noted.
A Gulfstream Captain reported that reloading the FMC after a runway change; using the same SID; some of the waypoints dropped out.