Date: 201505
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Aircraft: A320
Operator: Air Carrier
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
Aircraft component: GPWS
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Human factors: Human-Machine Interface; Situational Awareness
Second reporter function: First Officer; Pilot Flying
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft; Human Factors
Primary problem: Ambiguous

Narrative: At cruise- ECAM GPWS fault..went to FOM...allowance of Circuit Breaker (CB) pull in flight..28 VDC and 115 VAC...searched on panel 121VU ..located breakers below adiru. N6/N7. Both had corresponding 28 vdc/115 ac...never noticed right above same breakers p6/p7...upon pulling n6/n7...aircraft entered alt mode/ direct law after gear extension..contacted disp/ Maintenance Control tried to reinstate systems to original status..all breakers reset but not normal law...went through landing dist/ vref proc/ thrust issues for landing preparation ..destination not acceptable  due to landing distance...diverted.


Second narrative: Prior to top of descent I; the First Officer; was flying pilot with autopilot engaged. Ecam 'Nav GPWS fault' displayed. Followed QRH which has an air reset procedure. I remained flying pilot while the Captain searched the Circuit Breaker (COB) panel behind my head for the appropriate CB's. The Captain located the CB's after some time spent searching. He then asked me to verify the CB's before he did the reset. I turned in my seat as much as possible and craned my neck to see behind me and saw the GPWS label on the CB panel near where the Captains hand was and told him it was verified. The Captain then pulled the two CB's just below the correct breakers. Immediately; the First Officers PFD and MFD screens blanked out; the autopilot; autothrust; and flight directors disengaged and the aircraft reverted to alternate law.At that time my focus reverted to hand flying the aircraft via the Captains instruments which were functional except for the flight director. I flew the aircraft for the next few minutes until the Captain returned to his seat at which point he took the controls and I became the pilot monitoring. We now had additional ECAM messages which I tried to sort through while monitoring ATC. The Captain was communicating on comm 2 with the company to try and rectify the situation. At this point ATC started our descent and the workload increased significantly. I was giving hand signals to the Captain for speed and altitude assignments while the Captain was communicating with Maintenance Control and the company on comm 2 while also hand flying the aircraft.The decision was made to divert for the longer runways and the reduced flap setting that the checklist called for. We made the decision to [notify ATC of our situation] in order to reduce the workload on us that was increasing by trying to meet all the restrictions on the arrival while hand flying and working the problem. ATC gave us a heading and altitude for our diversion.The Captain briefed the flight attendants and passengers and we shot an uneventful visual approach. Captain asked me to control the thrust levers and speed on the final approach while he focused on smoothly hand flying in alternate and later direct law when the flight controls can be awkward and overly sensitive. The Captain resumed control of the thrust levers on short final. Uneventful landing.


Synopsis: A320 flight crew experiences an EGPWS fault prior to descent and checks manual for a circuit breaker pull and reset; which is allowed. Upon pulling and resetting N6/N7 on the 121VU panel the aircraft goes into alternate law and the crew diverts to a longer runway. Directly above N6/N7 are circuit breakers P6/P7 for the ADIRU's.