A320
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Distraction
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Environment - Non Weather Related; Procedure; Human Factors
I am a new hire on IOE and was paired with a company check airman. I as the FO was the PF doing the takeoff and departure from LAX. Prior to pushback we briefed; and were demonstrating a flap auto retraction; while climbing out of LAX on the ORCKA1 Departure. We were climbing on heading 251 climbing to DOCKR. We were asked by ATC to begin a southern turn. As the PNF and since I was hand flying; the Captain selected the heading and rolled it in the southern direction 15 degrees. I was head down; hand flying the aircraft and following the command bars as instructed by the Captain; so as to get the full benefit of the flap auto retraction exercise. At that time we experienced moderate bumps that I believe to have been wake turbulence from previously departed B757. This caused the Captain's iPad mount to come loose and fall. The Captain worked to reinstall the iPad; and find the departure procedure in order to identity the correct heading. At about the time the Captain was able to verify the correct heading; ATC advised us we had turned too far south and gave us a new heading. We complied and had no further issues. The FMS was verified and correct prior to takeoff. We discussed and briefed prior to push back the change in heading at DOCKR was 15 degrees. We speculate that ATC may have asked to begin our turn after the FMS was commanding our new heading of 236. So that when a southerly HDG was selected; we essentially were turning in addition to the correct HDG change. I the FO and PF was hand flying the airplane.I was focused on hand flying directly where the flight directors commanded; NAV had been captured and anticipating our auto flap retraction demonstration. I should have changed several things. First even though the headings were clear on the SID I should have written both initial headings on my paperwork. This is normally my practice with EO procedures and complex departures. I need to do this for all departures. The directions from the Controller were nonspecific. We were told to begin our southerly turn. If we were told to turn to a specific heading or if I would have asked to verify the heading he wanted there would have been no issue. Also in order to reduce my workload in that situation I should have engaged the autopilot as to have reduced my overall workload and widen the situational awareness of my scan.
A320 First Officer reported a wake turbulence encounter with a B757 contributed to a track deviation departing LAX.