Date: 201509
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Night
Aircraft: Skyhawk 172/Cutlass 172
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Initial Approach
ATC / advisory: TRACON ZZZ; Tower ZZZ
Reporter organization: Personal
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Human-Machine Interface; Situational Awareness
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Human Factors; Chart Or Publication
Primary problem: Human Factors

Narrative: After completing training at another airfield; myself and another instrument rated pilot proceeded towards ZZZ; having coordinated with Approach to conduct a couple of practice instrument approaches. Although I (pilot flying) had current paper approach plates in the aircraft; I opted not to use them as my safety pilot/SIC maintains a subscription to one of the electronic flight publications; and had all the approach plates available on his iPad. Additionally; he also subscribes to a service that provides increased situational awareness functionality including depiction of the aircraft (GPS position) superimposed on the approach plate. Since I am relatively unfamiliar with the newer electronic format (iPad in lieu of classic paper charts); the safety pilot offered to navigate the software and set navigational frequencies on the aircraft radios while I focused on the flying the approach; maintaining my instrument scan; and handling all voice communications and related setup. I accepted this offer and we agreed to distribute the workload in this manner. Our first practice approach was an ILS to Runway 18L. We both heard and confirmed Approach's acknowledgement that this would be radar vectors to ILS 18L; and I began flying the approach as directed (vectors); by now wearing a view limiting device. My safety pilot had earlier brought up the correct plate and entered/verified the navigational frequencies.  We both confirmed the frequencies; and that the correct plate was displayed. We also conducted an approach briefing and completed appropriate checklist actions. As expected; I was given a series of vectors aligning us for intercept of the final approach course. During this time; my safety pilot misunderstood one of the ATC radio calls; and believed we had been switched over to 18R. He remembers verbalizing 'sounds like 18R now' or simply '18R' at least once; and proceeded to switch to the 18R plate on his iPad. I missed his statement(s) and he failed to question why I therefore did not acknowledge. He also switched localizer frequencies on the nav/com radio; and although I did notice him adjusting the radio; I assumed that the adjustment was justified and correct; and did not question his actions. Once we were in range and could receive the Morse code identifier for the localizer; I took the action to verify we were on the right frequency by comparing the Morse code identifier to that depicted on the displayed approach plate (not realizing the iPad was now showing 18R; and my safety pilot not realizing that I was unaware he had updated the display). We both confirmed that the Morse code ID matched; again; each failing to realize that we were not on the same page (literally).As we continued on our final vector; I began intercepting the localizer for 18R (believing it was 18L) and everything cross checked and looked as it should from my perspective (sole reference to instruments). At the same time; everything appeared to be correct from my safety pilot's visual perspective since he believed we had been switched to 18R. Approach asked us to confirm we were established inbound; I acknowledged; and they handed us off to Tower. Immediately following check in; the Tower Controller asked me to confirm I was established inbound ILS 18L. This time I removed the hood; immediately realized we were intercepting the localizer for 18R in error; and replied 'Negative! Looks like we were tracking the wrong localizer' or something to that effect. Tower instructed us to turn left heading 090; climb and maintain 3;000; which I acknowledged and began to execute.We went on to conduct additional approaches with no further issues. Upon completion of our flight my safety pilot and I conducted a thorough after-action review and critical assessment of our errant first approach. I believe the primary cause of this incident was inadequate crew coordination:Regarding the electronic media; it took merely a tap of the screen to switch approach plates; which went completely unnoticed by me. I'm sure I would have noticed the SIC switching from one paper approach plate to another. Additionally; once on the final intercept heading; the safety pilot 'zoomed in' on the intercept point to show the intercept with increased precision.  This effectively omitted all other information on the chart and the 'big picture' view which may have helped me to recognize earlier that we were not in the correct position during intercept.




Synopsis: C172 Pilot In Command (PIC) flying a practice ILS approach to the left parallel runway missed the fact the Second In Command (SIC) misunderstood an ATC call as clearance to switch to the ILS for the right runway. SIC switched NAV to the right runway ILS without PIC being aware of the change until ATC advised of the course deviation from the left runway. Lack of crew coordination and electronic charts were cited as contributing to the incident.