Date: 201708
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: Rain; Thunderstorm
Light: Night
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Air Conditioning and Pressurization Pack
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted
Contributing factors: Aircraft; Weather
Primary problem: Aircraft

Narrative: From the moment we took off we encountered moderate turbulence and extreme rain showers. On the climb thru FL180 we remained in moderate turbulence; rain and begin picking up strong electrical fields around the cockpit or often referred to as St. Elmo's fire. This phenomenon continued through the flight until out of the weather. At approximately FL300 the left pack light came on. ATC had cleared us to FL400 but I requested to stop climb at FL320 to deal with pack issue. Shortly after the right pack light came on as well. I asked the FO to get out QRH and I took flying duties. He went to QRH for pack light on and I had my iPad out to follow along. He ran QRH and both packs reset. The cabin altitude was below 10000. At this point I turned the flying back to FO and informed ATC we would like to stay at FL320 inquired to ATC what was minimum safe altitude and we may have a problem and sent a call me message to dispatch. Very shortly after both packs came on again simultaneously. I requested lower immediately and received first of several descent altitudes. The FO decided to disengage the auto-pilot and start the descent. Given the weather; rain and St. Elmo sparking wildly I asked him to renegade the autopilot. I was still unable to get dispatch although they had provided a frequency to try. While descending I took note of cabin altitude but the conditions were very difficult at this point. I attempted a reset of packs again. We had now been cleared to 10000. At some point the cabin altitude warning came on during our descent at which point we took our O2 masks out and did our memory items. We remained in very difficult conditions due to rain; turbulence and St. Elmo to the point it was almost blinding in cockpit. I attempted several times to silence horn but due to the turbulence it was difficult to get my hand on the button. Once communications were established I tasked FO to [advise ATC] and we were going to ZZZ. We also decide that any faster descent would prove dangerous due to weather conditions. I attempted one last time to bring dispatch into loop on comm 2 and decide to send ACARS message 'diverting to ZZZ.' At some point we finally flew out of the weather and leveled off at 10000. The FO wanted to run the QRH for loss of cabin pressurization but I decided to finish the items on QRH for pack given we were now at 10000. I was now finally able to inform the FA of our situation and tell them what we were doing. Interestingly enough they did not inform me the mask had dropped in the back. I only was aware of that at gate when mechanic met us. We set up and executed landing at ZZZ. Fire rescue followed us to the gate and we completed the remaining required checklist. The mechanics met us and we briefed them and sent Maintenance writeups via ACARS. I called the Duty Manager. I inquired or requested a bit of guidance being a rather new Captain and the situation that just happened. Several things stand out from my conversation. First he basically wanted us to stay with airplane because again they wanted it in ZZZ2. He informed me they would possibly fix it and we would be legal to continue. I told him about the mask deploying and I felt that was doubtful. He also said there is a checklist he could run but seemed to think it wasn't really required. We waited and the FO and I debriefed. I was called back by the Duty Manager stating we would go to the hotel and ferry flight in morning. Crew scheduling decided minimum rest would be enough and built our ferry flight. We never flew that flight.The next morning I called the Union Chairman to get some advice on how to proceed. I never heard back. I also called another union rep because we were being pushed to ferry the flight and after reflection I thought it was vastly unfair to a new hire to force him to fly after such a difficult scenario. Union rep called me back and did call the FO. I also would like it to be noted the outstanding job the FO did during this incredibly difficult situation. There is irony that now the company has elected to remove us from flying while an investigation is being conducted when they seemed willing to fly us right back that morning twice. This report is being filed to the best of my recollection of the events.




Synopsis: B737 Captain reported a dual air conditioning pack failure while climbing out and subsequent divert.