Flight Crew Commercial
Workload; Distraction; Training / Qualification; Communication Breakdown
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Other / Unknown
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Environment - Non Weather Related; Human Factors
[It] was my first day back on the job after taking the [previous] month off due to the birth of my first child; so it had been a while since I'd been in the flight deck.  I really hadn't thought about flying much at all for the entire month due to the focus on having a new baby around.  My Captain was fresh off IOE (I think the trip may have been his first since IOE); and we had a jumpseater who was in training about to begin OE who was there to observe.  The jumpseater had been asking a lot of questions during both the flight out; and this flight back.  I found it a little distracting; but as a former ground instructor I have the attitude that if I can help someone learn I'd like to.  I probably should have called for sterile cockpit a couple of times though when discussion was too much. We took off of Runway XXL; and if I remember correctly I think we were on runway heading for the initial climb.  Shortly thereafter; we were assigned a turn to a 090 heading; and when able; direct an arrival intersection.  When I first armed NAV mode and it captured; the aircraft started to turn left.  The jumpseater said he thought we were supposed to turn right to 090; then direct the intersection; so we asked ATC and they said; 'Yes; turn right to 090 then direct the intersection when able.'  I was glad in this case that the jumpseater spoke up as it was appropriate.  I put the aircraft back into HDG mode and made sure it made the turn to 090 by going to the right.  However; with all the further discussion going on between the three of us; I became distracted and apparently did not arm NAV mode for the FMS to capture the route direct to the intersection; and the Captain and jumpseater did not notice either.  After an unknown time (probably a minute but I'm not sure); ATC asked if we were direct the intersection; and we realized and admitted the mistake to the Controller.  She gave us a new HDG; then direct again; and we correctly got on the new assigned course.  The Controller did not seem upset and to my knowledge there were no traffic or any other issues as a result.  I believe the event happened due to the combination of my being out of work for several weeks; the Captain being new to the airplane; and all of the disjointed discussion between the three of us during the event.
A CRJ-200 First Officer reported a track deviation after he failed to select an MCP heading and engage the NAV mode because of distractions from a new hire jumpseat pilot and a just completed IOE Captain.