Date: 201811
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: IMC
Light: Dawn
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: FMS/FMC
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Diverted; Flight Crew Landed As Precaution; General Maintenance Action
Contributing factors: Aircraft; Weather
Primary problem: Weather

Narrative: During climbout; aircraft took what crew believed to be a lightning strike to the left side. Over a period of time the aircraft lost all information in the FMC except for lateral routing. No N1 information; vertical guidance or fuel burn calculations were available. Mode Control Panel had no pitch inputs available such as Level Change; Vertical Speed; and VNAV. The autopilot functioned only with LNAV. Heading Select would not work. Autopilot pitch was limited to CWS. No flight directors were available. No autothrottle was available. Annunciation above N1 gauges read A/T LMT in white. Weather conditions departing ZZZ was low ceilings; visibility less than a mile; rain RA LLWS. Entire area had similar weather. Destination weather at ZZZ1 was low ceilings; light rain. Forecast weather at ETA was winds 14022G30KT. This would have been a 22-30 knot crosswind for Runway XX.Crew determined flying aircraft back into weather at ZZZ or continuing to ZZZ1 with forecast weather would not be the safest course of action. Crew elected to continue to destination alternate where the weather was VFR; light winds. Crew found that altitude hold function was not functional on autopilot and advised ATC flight would be unable RVSM. ATC cleared flight to non-RVSM airspace. Dispatch was notified that flight was proceeding to alternate ZZZ2. Flight Attendants and passengers were informed of landing in ZZZ2 due to the lightning strike and inoperative navigational guidance abilities. After parking at gate; Dispatch was notified; a three way conversation took place with Chief Pilot on call. We then had conversation with Maintenance Control. Aircraft logbook was written up on three different pages to include lightning strike; FMC; MCP issues. Flight Ops Management personnel debriefed flight crew after aircraft was towed off gate for Maintenance inspections.


Second narrative: We departed ZZZ for ZZZ1 and during climbout at about 9000 feet we experienced a lightning strike. Shortly afterward we noticed an 'A/T Limit' message above the N1 gauges and the autothrottles didn't have the engines set to the green band. After a few minutes the message went away but there were green dashed lines in place of the normal numeric N1 settings next to the engine indication dials. Within the next few minutes the Captain tried to select the autopilot on but it wouldn't engage. We then noticed the flight directors were not working and none of the selectable modes on the autopilot panel would work. After checking the FMC we noticed the FMC was missing the engine N1 numbers from the N1 Limit page and there were no fuel burn computations from the FMC either. We then decided to divert to our planned alternate. After leveling at our planned cruise altitude of 31;000 feet we realized that with the current malfunctions we weren't RVSM capable and requested a descent. The rest of the flight was uneventful and we landed safely.


Synopsis: B737-700 flight crew reported diverting to an alternate after a lightning strike resulted in multiple FMS anomalies.