Date: 202112
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: IMC
Light: Night
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: Fuselage Bulkhead
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Situational Awareness; Fatigue; Communication Breakdown; Troubleshooting
Second reporter function: Pilot Not Flying; Captain
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate
Result: General Release Refused / Aircraft Not Accepted
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Aircraft

Narrative: I was assigned to fly the freighter ZZZ-ZZZ1. Upon arrival in operations I was notified that the plane wouldn't likely be to the cargo parking area until around XA00; even though we had a XB55 departure time scheduled. When I met the Captain I relayed what I had heard about the arrival time and he offered the idea to taxi the plane from the maintenance hangar to cargo parking. When we arrived at the hanger we were notified it was there because it had previously been involved with a fire in the ground power receptacle area. Reviewing the logbook also indicated the aircraft had been involved with a fire and had multiple repairs done because of the fire; including damage to a pressure vessel seal.I performed a personal assessment of the threats for a roughly 3 hour 45 minute flight to ZZZ1 that we were facing. -Airplane just out of maintenance with no functional check flight.-night flight.-poor weather currently and in the forecast for ZZZ.-poor weather along the route to ZZZ1.-unknown runway conditions along route.-possibly no ARFF (Airport Rescue and Fire Fighting) along the route.-still need reposition from hangar to cargo.-still needed to be loaded with cargo.-needed lots of de-ice.-both pilots only getting more fatigued.-best case scenario; we would depart around XA30 after showing at XC55.I expressed my concerns to the Captain and said I'm of the opinion that the airplane should have a functional check flight prior to it operating again. Also; the fear of if we have a problem; we have almost zero divert options. Captain then called flight operations to consult the concerns and they indicated that the fire was suspected to be caused from the ground power cart cable and indicated that after consulting with Maintenance; it seems safe to proceed with the flight. Reviewing the verbiage of the FOM; it states that a functional check flight is required after major work is performed and Flight Operations or Maintenance can request the flight. We jointly decided that the repairs done should warrant a functional check flight.It was then that the Captain communicated flight operations that we are opting to decline the airplane.


Second narrative: I was assigned Aircraft X. After tracking down the aircraft at the maintenance hangar I was made aware that the aircraft was down being worked on due to an electrical fire on Date. Upon completing my pre-flight review of the logbook and having a discussion with my FO (First Officer); we both had concerns that the aircraft required a FCF (Functional Check Flight) flight prior to return to revenue service. FOM states that 'FCFs are required after certain heavy checks or major work on an aircraft.' There were over 10 pages in the maintenance logbook detailing various defects and resolutions associated with the electrical fire. In my judgment; what I was seeing in the logbook and what I had been made aware of by our mechanics constituted 'major work;' and as such I believe a FCF was required. Also; while conducting my pre-flight review of the logbook; I turned on the APU and once the required time had passed; I turned the packs on and smelled an acrid; burned electrical smell.I placed a call to the flight operations to express my concerns and inquire about whether a FCF flight was required. I specifically stated that flying from ZZZ-ZZZ1 during the middle of the night; with very limited divert options (which were further limited by inclement whether and snowy conditions in ZZZ and extending all the way to ZZZ1) and an aircraft that had just had an electrical fire; didn't seem like a very safe decision without confirming (via a FCF) that the aircraft was fully functional in a more contained setting with two qualified FCF pilots. Flight operations was very supportive and had a consultation with maintenance in which they told him that a FCF was not required. I said I was uncomfortable operating this aircraft and my best and safest judgement call would be to refuse the aircraft. I inquired about swapping into another aircraft so that we could complete our assigned flight/pairing; but unfortunately none was available.That is pretty much the end of the narrative. I tried to honor the verbiage and I believe the intent of the FOM language regarding FCF flights and aircraft returning to service after major work being performed. Ultimately; I felt that it was a safety issue that could have had very serious ramifications; so I used my best judgement to make a very difficult decision.I'd like some feedback on what constitutes 'major work' on an aircraft and when a FCF flight is required prior to returning one of our aircraft to revenue service. There was some definite disagreement between what I was reading in the FOM; reading in the aircraft logbook; and what Maintenance was telling flight operations. I believe I applied the correct judgement based on our FOM guidance; and I know it was certainly the conservative and safest course of action; but I've honestly never run up against this scenario during my career at Company before and it would be useful for me to know more on this subject so that I can hopefully make the right judgment call(s) going forward.


Synopsis: B737-700 flight crew reported refusing the aircraft because the requirement of a Functional Check Flight after a major repair was not met.