Date: 201306
Local time of day: 1801-2400
Location: YSSY.Airport, FO
Weather elements / visibility: Rain; Thunderstorm
Aircraft: Widebody Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Takeoff / Launch
ATC / advisory: Tower YSSY
Aircraft component: FMS/FMC
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Communication Breakdown; Confusion; Situational Awareness
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Contributing factors: Procedure; Human Factors; Aircraft
Primary problem: Aircraft

Narrative: Shortly before clearance onto the active; we were given a 'turn to' heading on departure. That was set into the FCP. Unfortunately the turn began in the wrong direction when selected after takeoff. An immediate correction was made. Physical preparation for departure began in the chocks with the discussion of which SID was anticipated for the leg. The two similar departures call for tracking segments with attention paid to dual runway operations and warnings and cautions for parallel runway traffic. That's all fine. While still not 100% certain of the exact point at which the error was introduced; I suspect it may have been selecting 'NAV' early in the preparation for departure. I've noticed a trend on the line to make the 'NAV' selection well before the 'below the line' portion of the Before Takeoff Checklist. In recent history; I've experienced two occasions where I've been surprised at events after coupling the flight controls to the autopilot; this occasion; and another time when the updated instructions from Tower for departure heading was made by the pilot not flying. In the present case; the checklist was run and departure instructions reviewed. We caught the error in a timely manner corrected to the directed heading.


Second narrative: SYD 4 departure says 'track 155' off of 16R; so we were planning on using NAV for the departure. On the clearance for takeoff; Tower gave us a 170 heading after takeoff. While I was doing below the line of the Before Takeoff Checklist; the Captain dialed in 170 in the heading bug. At 500 FT after takeoff; the Captain selected auto flight; prof; and pulled the heading bug; the plane started turning left (it was supposed to be a right turn to 170). He immediately disconnected the autopilot; and turned right to 170. Tower didn't say anything; but Departure asked if we were heading 170; and at that point we were. Threats were expectation bias; we had briefed and loaded the FMS for a 155 track; we didn't expect the 170 heading; and didn't check the way the plane would turn. We also had moderate to heavy rain; causing a max power takeoff (wet runway on ATIS); which might have added to our loss of situational awareness.


Synopsis: Air carrier flight crew departed on YSSY SYD 4 departure with an ATC assigned heading; but the Captain engaged the autopilot with NAV active on the SYD 4 and turned the wrong direction before catching the error and correcting it.