On flight from Avignon to Ljubljana on August 31st I got lightning strike during descent towards Ljubljana airport.
We took off at 12:15 UTC from LFMV and majority of the flight was in VMC above cloud tops except part of departure. I noted storm-cell developing activities both north and south from our route using on board stormscope and ADL120.
During descent through TCU clouds towards Ljubljana airport, electrical discharge hit the aircraft. Stormscope showed full screen of electrical activity and then continued to throw lightning failed error.
I disengaged autopilot, checked aircraft controls, lowered airspeed, continued descent and started to asses other possible damage. Both engines were functioning correctly, responding to increased and decreased throttle. Airspeed indicators and engine indicators were consistent as well as both attitude indicators and both altimeters. I checked landing gear (down and up) and checked flaps (lowered them to approach position and up), noting correct functioning.
I noticed black spot on left winglet assuming this to be discharge exit point. We left IMC before reaching assigned altitude and I reported incident to ATC and asked to divert to Lesce (LJBL – Diamond service is located there) for full check required after lightning strike. I also noticed smaller black spot on right winglet as well. At that moment we were at approximately same distance from LJLJ and LJBL in full VMC conditions so I decided that’s more practical to land at LJBL.
Divert was approved as well as visual descend to 1000 feet AGL, no help in navigation was needed since we were visual and majority of avionics was working correctly. I crosschecked aircraft’s GPS with the one on iPad, checked both radio stations and both NAV receivers, DME and ADF and everything seemed to function correctly. Further check showed that main tanks fuel indicators didn’t work but according to flight log (64.7 USG at takeoff and average 11 USG/h within 3 hours of flight) and fuel totalizer, we were ok with fuel assuming no leaks. However, I reported this to ATC as well.
At that moment I had LJLJ airfield in sight and after arriving traffic I was allowed to descent further to W2 and W1 points towards LJBL airfield. When reaching W2 I got permission to leave the frequency and to switch to Lesce and I asked for flight plan to remain open until I confirm successful landing with phone call from ground.
Runway in used at LJBL was 14; I reported W1 and later on final runway 14, got permission for landing and successfully landed aircraft at 15:35 UTC.
Seems to me like you did a good job and took the right decisions. Very interesting pictures. I hope that you will share the aftermaths of this when it comes the required inspections and work post a lightning strike. I hope that you will get the airplane back into the air soon.
I didn’t post anything in public before clarifying all issues with insurance. First call after landing was to ATC, second to mechanic and third to insurance. Then I called my mom to let her know we landed safely 
Repair started today and required procedure is described in Maintenance Manual – I think it starts with dismantling the wings and ends with bond testing. It will take some to weeks to have it back in the air if everything goes without surprises and additional internal damage.
I bet that was an interesting experience and job well done.
It is not a crticism for one moment but the only thing that occurred to me reading your report is why you lowered and raised the u/c? I can appreciate you wanted to check it worked but I think I would have lowered it early before landing and left it down if only to avoid any risk of it not coming down the second time.
Fuji_Abound wrote:
I can appreciate you wanted to check it worked but I think I would have lowered it early before landing and left it down if only to avoid any risk of it not coming down the second time.
Good point – I wasn’t thinking about it – it was more like “let’s check it, it’s ok, let’s retract it” and I did sam for flaps.
Good work, Emir! Thanks for sharing.
The sound of the lightning hitting the aircraft must have been deafening?
It’s a DA42. Probably barely audible over the engine noise.
lenthamen wrote:
The sound of the lightning hitting the aircraft must have been deafening?
As far as I know, you don’t hear much in the immediate vicinity of the discharge. I haven’t experienced a strike in the air, but have been several metres away from one in the mountains. It sounded more like a big stick being broken in half – a short series of crackles.
Well done, Emir. You were lucky, because a DA 42 crashed in Germany a few years ago after a lightning strike killing the pilot.
The sound of the lightning hitting the aircraft must have been deafening?
No sound at all, just wave of warmth.
