Narrative:

I was captain on the flight, the first flight of the day, departing on time at XA00 and arriving at XA25. On descent into the ZZZ area (at approximately the zzzzz intersection on the zzzzz nine arrival) we heard a clap of thunder accompanied by a flash of lightning. (I have never been in an aircraft struck by lightning, so I asked the copilot if he had ever been involved in a lightning strike. (We were IMC at the time) he said 'yes, a couple of times,' but this was not similar to any of his experiences. He said all the other lightning encounters were much louder with associated electrical problems (like generators falling off line and so forth). We had no evident electrical problems. Just to be on the safe side, I called ZZZ maintenance to meet us at the aircraft upon arrival. All was normal on descent and landing. At the gate, a ZZZ maintenance man inspected the aircraft. I told him what we experienced and said that it probably was not a lightning strike, but let's check it out just in case. He inspected the aircraft while I looked at the nose area. After about 10 mins, maintenance told me that he did not see any evidence of lightning damage. He checked the entire aircraft and would also get a ladder and check the top of the aircraft. I then went up to meet the outgoing captain and relayed the message. The new captain asked me if I felt any 'heat' when I saw the lightning and I said no. He said that when he had a lightning strike, he felt heat on the side of his face toward the lightning so he also doubted it was a lightning strike. I handed the plane over to him and we left. After the trip, I received a phone call from the chief pilot's office asking me about a hole in the leading edge of the vertical stabilizer of the aircraft. I had no knowledge of it. We received the aircraft in ZZZ1, and flew it for 1 leg to ZZZ. We did not get deiced. It was not mentioned to me by the previous crew, my first officer from his walkaround, nor by the maintenance man in ZZZ who had inspected the whole aircraft for lightning damage before we handed the plane over to the next crew. It was evidently seen by the new first officer, after his walkaround, while he was casually looking at the tail of the aircraft from the jetway after all passenger had boarded. Supplemental information from acn 535059: I did the preflight on the aircraft and observed no damage to the aircraft. I was later advised that damage to the vertical fin of the aircraft was found. Maintenance inspected the aircraft and found no damage. At that time we left the aircraft with the outbound crew. Supplemental information from acn 535057: I was informed that the aircraft I flew was damaged. My first officer performed 3 different walkarounds on that day. There was no damage during our phase of flying the aircraft that day. I have no knowledge of the damage or what event may have caused it.

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Original NASA ASRS Text

Title: A B737-700 ON DSCNT MAY HAVE EXPERIENCED A LIGHTNING STRIKE INCURRING DAMAGE TO THE VERT STABILIZER NOT DISCOVERED ON LIGHTNING STRIKE INSPECTION OR FO'S INSPECTION.

Narrative: I WAS CAPT ON THE FLT, THE FIRST FLT OF THE DAY, DEPARTING ON TIME AT XA00 AND ARRIVING AT XA25. ON DSCNT INTO THE ZZZ AREA (AT APPROX THE ZZZZZ INTXN ON THE ZZZZZ NINE ARR) WE HEARD A CLAP OF THUNDER ACCOMPANIED BY A FLASH OF LIGHTNING. (I HAVE NEVER BEEN IN AN ACFT STRUCK BY LIGHTNING, SO I ASKED THE COPLT IF HE HAD EVER BEEN INVOLVED IN A LIGHTNING STRIKE. (WE WERE IMC AT THE TIME) HE SAID 'YES, A COUPLE OF TIMES,' BUT THIS WAS NOT SIMILAR TO ANY OF HIS EXPERIENCES. HE SAID ALL THE OTHER LIGHTNING ENCOUNTERS WERE MUCH LOUDER WITH ASSOCIATED ELECTRICAL PROBS (LIKE GENERATORS FALLING OFF LINE AND SO FORTH). WE HAD NO EVIDENT ELECTRICAL PROBS. JUST TO BE ON THE SAFE SIDE, I CALLED ZZZ MAINT TO MEET US AT THE ACFT UPON ARR. ALL WAS NORMAL ON DSCNT AND LNDG. AT THE GATE, A ZZZ MAINT MAN INSPECTED THE ACFT. I TOLD HIM WHAT WE EXPERIENCED AND SAID THAT IT PROBABLY WAS NOT A LIGHTNING STRIKE, BUT LET'S CHK IT OUT JUST IN CASE. HE INSPECTED THE ACFT WHILE I LOOKED AT THE NOSE AREA. AFTER ABOUT 10 MINS, MAINT TOLD ME THAT HE DID NOT SEE ANY EVIDENCE OF LIGHTNING DAMAGE. HE CHKED THE ENTIRE ACFT AND WOULD ALSO GET A LADDER AND CHK THE TOP OF THE ACFT. I THEN WENT UP TO MEET THE OUTGOING CAPT AND RELAYED THE MESSAGE. THE NEW CAPT ASKED ME IF I FELT ANY 'HEAT' WHEN I SAW THE LIGHTNING AND I SAID NO. HE SAID THAT WHEN HE HAD A LIGHTNING STRIKE, HE FELT HEAT ON THE SIDE OF HIS FACE TOWARD THE LIGHTNING SO HE ALSO DOUBTED IT WAS A LIGHTNING STRIKE. I HANDED THE PLANE OVER TO HIM AND WE LEFT. AFTER THE TRIP, I RECEIVED A PHONE CALL FROM THE CHIEF PLT'S OFFICE ASKING ME ABOUT A HOLE IN THE LEADING EDGE OF THE VERT STABILIZER OF THE ACFT. I HAD NO KNOWLEDGE OF IT. WE RECEIVED THE ACFT IN ZZZ1, AND FLEW IT FOR 1 LEG TO ZZZ. WE DID NOT GET DEICED. IT WAS NOT MENTIONED TO ME BY THE PREVIOUS CREW, MY FO FROM HIS WALKAROUND, NOR BY THE MAINT MAN IN ZZZ WHO HAD INSPECTED THE WHOLE ACFT FOR LIGHTNING DAMAGE BEFORE WE HANDED THE PLANE OVER TO THE NEXT CREW. IT WAS EVIDENTLY SEEN BY THE NEW FO, AFTER HIS WALKAROUND, WHILE HE WAS CASUALLY LOOKING AT THE TAIL OF THE ACFT FROM THE JETWAY AFTER ALL PAX HAD BOARDED. SUPPLEMENTAL INFO FROM ACN 535059: I DID THE PREFLT ON THE ACFT AND OBSERVED NO DAMAGE TO THE ACFT. I WAS LATER ADVISED THAT DAMAGE TO THE VERT FIN OF THE ACFT WAS FOUND. MAINT INSPECTED THE ACFT AND FOUND NO DAMAGE. AT THAT TIME WE LEFT THE ACFT WITH THE OUTBOUND CREW. SUPPLEMENTAL INFO FROM ACN 535057: I WAS INFORMED THAT THE ACFT I FLEW WAS DAMAGED. MY FO PERFORMED 3 DIFFERENT WALKAROUNDS ON THAT DAY. THERE WAS NO DAMAGE DURING OUR PHASE OF FLYING THE ACFT THAT DAY. I HAVE NO KNOWLEDGE OF THE DAMAGE OR WHAT EVENT MAY HAVE CAUSED IT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.