MD11 Captain reported an airspeed unreliable event after a static discharge while descending through an area of convective activity. Crew performed checklists and landed uneventfully.

Narrative

The FO is the pilot flying (he did an outstanding job)!!!We were avoiding a line of thunderstorms going into ZZZ that started with a mutually agreed upon path and plan with ZZZ center approximately 200 miles south of ZZZ. This plan included direct to point ZZZ1 east of ZZZ keeping us east of the line of thunderstorms and going around the north end of that line and approaching ZZZ from the north avoiding the weather. Approximately 100 miles from ZZZ1 we were handed off to ZZZ1 center. ZZZ1 center appeared to have issue with our and ZZZ centers mutually agreed upon plan because it would take us through ZZZ2 approaches Class B airspace. ZZZ1 center said they would talk to ZZZ2 approach and get back. He also gave us a decent to FL240. Descending through about FL280 we entered moderate chop turbulence and slowed to 290 IAS. ZZZ2 came back and asked us what our plan was. He didn't think he could allow us to go all the way to ZZZ1. I told center to stand by. After talking with my FO; utilizing the weather radar to paint the weather all the way down to ground returns; we came up with a plan turn roughly 20 miles to the south of ZZZ1 and proceed direct to ZZZZZ; a point listed east of the ZZZZZ1on the RNAV approach to Runway XX at ZZZ. This plan avoided all red returns on our weather radar; however it did put us having to fly through yellow returns quite a bit. We were given direct ZZZZZ decent to FL200 and subsequently 13;000 feet. Descending through about FL240 we also started picking up moderate turbulence and static on the radio making it difficult to communicate with ZZZ1 center; so much so that I requested ZZZ1 center send our communications via CPDLC. We also slowed to 250 KIAS. Descending through FL200 my FO and I noticed a bright flash of lightning; followed almost immediately by two amber IAS indications in our primary flight displays. The autopilot and auto-throttles kicked off. Level 2 and level 1 warning indications also appeared. In analyzing our situation; we determined my airspeed was 5 knots slower than both the FOs airspeed indication and the standbys. We performed the immediate action items of the Airspeed unreliable checklist. I [advised ATC] with ZZZ1 center. ZZZ2 heard our [request for priority handling] but didn't hear our call sign. With our request; and suspected confusion of who requested it; the radio subsequently erupted with garbled chatter because of all the static and weather we found ourselves climbing back into. I squawked XXXX. The immediate action items of the Airspeed Unreliable Checklist have you set 4-degree pitch for a clean configuration aircraft and 90% N1 with the throttles. I believe this is to keep you in a safe altitude and airspeed envelope of a worst-case scenario heavy aircraft of 630;000 lbs. We were roughly 350;000 lbs.; so 2 degrees and 70% N1 would be our null pitch and power setting for 20;000 feet. Needless to say; 4 degrees and 90% N1 had us accelerating quite quickly and climbing back up into stuff I didn't really want to climb back up into. The turbulence was moderate+; I wouldn't say severe because I've been in severe and I got dirt in my eyes from the floor of the aircraft then. But it was bad enough I couldn't read the checklist initially. The checklist had us lose both flight directors and autopilot and auto throttles in the weather; moderate + turbulence; thunderstorms and lightning in the vicinity; and verbal communication with ATC negligible. We both had a HANDFUL of airplanes. Adrenaline was pumping. We soon got into more stable air and were able to complete the checklist. The checklist was thorough; and did lead us to determine the captain's side was the bad info. My airspeed was indicating never more than 5 knots below the FOs and the standby airspeed. Static was so bad I could hardly communicate with ZZZ2. We didn't or should I say couldn't talk much with ZZZ2 during this event. We were handed off to ZZZ approach via CPDLC.Did I mention the FO did an outstanding job!!!?With the environmental problems we were having the checklist took time to complete. After completion of the checklist; we had a stable aircraft with the bad information side isolated. Subsequently we were high and had time to descend and get vectored for the approach. As stated previously; we had several level 2 and level 1 warning indications that came and went throughout this 25-minute event. During this time; we discussed the situation; the RNAV approach; and weather; turbulence; lack of auto pilot; auto throttles; and flight director. Also; the negative impact that we would have HAND flying the RNAV approach in the weather and turbulence. We discussed the inherent increased risks associated with these factors. Because of the potential corrupt input from other systems; we were cautious and concerned when flipping switches that we could possibly inject erroneous inputs into our current stable state. The turbulence had negative impact on airspeed and aircraft control. We both agreed and came to the conclusion that we'd love to try and at least get the flight director back. The aircraft was stable in both pitch and power. We decided to turn the FOs flight director back on and see what happens with the agreement to immediately turn it back off should any adverse effects resurface. We did; he got his flight director back. We also discussed and subsequently decided to turn the FOs AFS switch on and at least attempt to get the auto throttles back with the agreement wed turn it off immediately if any adverse effects surfaced. We engaged PROF with the #2 AFS switch re-engaged. The auto throttles came back and worked perfectly. We subsequently decided to try the #2 auto pilot. It also worked perfectly. We completed the Airspeed Unreliable checklist.We flew the RNAV Runway XX approach disconnected the auto pilot just inside the final approach fix and landed uneventfully.With unreliable airspeed; finding day VFR flight conditions is always plan A. This was a scary situation. Can't laud my FO enough. His flying ability and CRM input is exceptional. His ability to maintain aircraft control in a very reduced controllability environment made it easier for us to analyze the situation and take the appropriate coordinated action. Plan B not only worked; it worked well.Human factors: Two human factors very important that we had to deal with are FEAR and ANXIETY.FEAR: I couldn't initially read the checklist because of how badly we were being bounced around. Not being able to communicate with ATC also increased my level of anxiety I had from not being able to read the checklist. I had in the not too distant past; performed this same checklist in the simulator. I remembered reading in the AOM when I studied for this prior to performing it in the sim; that airspeed unreliable and the amber IAS indications were caused by a bad static air source or bad CADC (central air data computer)or both. I couldn't initially read the checklist but I knew I needed to move the static air source and CADC switches. In the heat of this moment; the location of my static air switch was eluding me. FEAR was clouding my mental state but fortunately PANIC had not set in. I remember; from the sim; wanting to be the guy flying. The guy flying had one job; set 4 degree and 90%. That's it; easy job. I remember momentarily looking at my FO. All of a sudden; I didn't want to be the guy flying. (There's an older piece of gym equipment that instantly came to mind. Its a bicycle/fan put together where you peddle the bicycle and row your arms to move the fan. That mental picture resembled my FO.) I wouldn't say humor replaced FEAR but my time clock slowed; my heart rate slowed and I found the static air switch and my CADC switches. At that point in time we had enough reliable information to fly this RNAV approach. We later got into smoother air and were able to read and complete the checklist. But I didn't know we would be able to do that at that time. What if we could never read the checklist? Ill have a different attitude about reading my AOM emergency checklist now with a motivation of being able to get switches in the right place and have an understanding of how the checklist runs to safely put an aircraft on the ground.ANXIETY: Anxiety also manifested itself into a lets get this beast on the ground now mentality. I remember telling ZZZ3Approach I had the runway in sight prior to confirming it with my FO. Approach immediately cleared me for the visual and handed me off to tower. I changed to Tower frequency and immediately informed tower we wanted to stay on the RNAV approach.Recommendations: me especially…stay in the books; know your aircraft! Also; hindsight; I'd have been more adamant with ZZZ1 center with our original plan and forced the issue with ZZZ1center coordinating with ZZZ2Approach and approving our entry into their Class B airspace.I was a flight safety mishap investigator for many years. I've investigated many more of these types of events than I've written. Flight safety is very important; but can be dry and boring. Some will critique me and say I should leave personality or the thoughts that popped up in my head in an event out; and just stick to facts. I disagree. Our thoughts and state of mind either help or hinder the effectiveness of our crew during critical moments. There are human factors; thoughts that affect the timeliness and effectiveness of a crew. Human factors; thoughts; that can paint a more vivid picture and hopefully enable a reader to insert themselves into the cockpit and chair fly alongside. This word picture hopefully provides benefits from not only gaining a better understanding of the events taking place; but also helps increase situational awareness. In the event the reader ever finds themselves in a similar situation; I pray they'll be better equipped for a safe and successful outcome.