Narrative:

A friend of mine was captain of this flight and experienced two separate lightning strikes on approximately a 6 mile final to ZZZ airport; he related the story to me at the end of his trip. I am filing this ASRS report because my airline's fleet of 777's seem to experience lightning strikes and/or static discharges much more frequently than do our other types. I base this observation on my own experience on the 777 as first officer and on the experiences of my friends who are or who have been on the fleet. Also; it's based on the maintenance log history that I've seen on the aircraft. I experienced the worst static discharge of my career while a 777 first officer about 4 years ago when just about to exit a small; stand alone rain cell about 4 miles in diameter. We had asked to deviate around the cell; but were unable to due to traffic. Our x-band radar showed the cell to be symmetrical with no sharp edges and 'painting' only yellow in the middle. The cell contained only moderate rain and light turbulence with no observed icing or lightning. Based on our altitude (13000 ft MSL) and the surface temperature (approximately 60 F) I would estimate the sat to be just below freezing. Just prior to exiting the cell; we had an extremely loud static discharge on the left side of the fuselage between door 1L and 2L that left a burn mark 10 ft long. Based on my observation of our fleet's maintenance histories; most of the discharges and lightning strikes occur forward of the wing. The fly by wire controls were not affected on my aircraft during the discharge nor apparently were any of the other systems. My concern is that perhaps the carbon fiber and epoxy composite construction prevalent in the tail surfaces of the 777 set up an electrical potential between the tail and the front of the aircraft where composite structure and surfaces are not so common or perhaps the composite materials are themselves more prone to discharge than conventional structures and surfaces. I'd like to recommend that NASA look into maintenance histories for 777's worldwide to see if there is a trend along these lines.callback conversation with reporter revealed the following information: reporter stated there was little; if any; static noticed in the B777 communication radios during static environments as compared to the older boeing B727 radios. Reporter was curious if the static discharges were similar to direct current (D.C.) discharges and whether or not the increased use of carbon fiber in aircraft construction; contributes to some type of increased ionization that affects the severity of static discharges. Reporter also stated he now flies the airbus A320 and has had numerous; serious static discharges that required him; on one occasion; to go from 'alternate law' to 'direct law' for landing his A320 due to losing the aircraft's air data/inertial reference units (adiru) and control display unit (CDU). Reporter wonders if these static discharges are inducing a type of electromagnetic impulse or interference (EMI) within the aircraft's circuitry that overload the wires and cause the glass cockpit or certain CDU's to go dark. Radio communication static interference was more noticeable on the airbus A320 than on the B777 aircraft during lightning or static environments.

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Original NASA ASRS Text

Title: A B777-200 PLT RPTS ABOUT HIS EXPERIENCES OF MORE FREQUENT LIGHTNING STRIKES AND/OR STATIC DISCHARGES ON HIS CARRIER'S B777 FLEET COMPARED TO OTHER FLEET ACFT.

Narrative: A FRIEND OF MINE WAS CAPT OF THIS FLIGHT AND EXPERIENCED TWO SEPARATE LIGHTNING STRIKES ON APPROX A 6 MILE FINAL TO ZZZ ARPT; HE RELATED THE STORY TO ME AT THE END OF HIS TRIP. I AM FILING THIS ASRS RPT BECAUSE MY AIRLINE'S FLEET OF 777'S SEEM TO EXPERIENCE LIGHTNING STRIKES AND/OR STATIC DISCHARGES MUCH MORE FREQUENTLY THAN DO OUR OTHER TYPES. I BASE THIS OBSERVATION ON MY OWN EXPERIENCE ON THE 777 AS FO AND ON THE EXPERIENCES OF MY FRIENDS WHO ARE OR WHO HAVE BEEN ON THE FLEET. ALSO; IT'S BASED ON THE MAINT LOG HISTORY THAT I'VE SEEN ON THE ACFT. I EXPERIENCED THE WORST STATIC DISCHARGE OF MY CAREER WHILE A 777 FO ABOUT 4 YEARS AGO WHEN JUST ABOUT TO EXIT A SMALL; STAND ALONE RAIN CELL ABOUT 4 MILES IN DIAMETER. WE HAD ASKED TO DEVIATE AROUND THE CELL; BUT WERE UNABLE TO DUE TO TFC. OUR X-BAND RADAR SHOWED THE CELL TO BE SYMMETRICAL WITH NO SHARP EDGES AND 'PAINTING' ONLY YELLOW IN THE MIDDLE. THE CELL CONTAINED ONLY MODERATE RAIN AND LIGHT TURB WITH NO OBSERVED ICING OR LIGHTNING. BASED ON OUR ALT (13000 FT MSL) AND THE SURFACE TEMP (APPROX 60 F) I WOULD ESTIMATE THE SAT TO BE JUST BELOW FREEZING. JUST PRIOR TO EXITING THE CELL; WE HAD AN EXTREMELY LOUD STATIC DISCHARGE ON THE L SIDE OF THE FUSELAGE BETWEEN DOOR 1L AND 2L THAT LEFT A BURN MARK 10 FT LONG. BASED ON MY OBSERVATION OF OUR FLEET'S MAINT HISTORIES; MOST OF THE DISCHARGES AND LIGHTNING STRIKES OCCUR FORWARD OF THE WING. THE FLY BY WIRE CONTROLS WERE NOT AFFECTED ON MY ACFT DURING THE DISCHARGE NOR APPARENTLY WERE ANY OF THE OTHER SYSTEMS. MY CONCERN IS THAT PERHAPS THE CARBON FIBER AND EPOXY COMPOSITE CONSTRUCTION PREVALENT IN THE TAIL SURFACES OF THE 777 SET UP AN ELECTRICAL POTENTIAL BETWEEN THE TAIL AND THE FRONT OF THE ACFT WHERE COMPOSITE STRUCTURE AND SURFACES ARE NOT SO COMMON OR PERHAPS THE COMPOSITE MATERIALS ARE THEMSELVES MORE PRONE TO DISCHARGE THAN CONVENTIONAL STRUCTURES AND SURFACES. I'D LIKE TO RECOMMEND THAT NASA LOOK INTO MAINT HISTORIES FOR 777'S WORLDWIDE TO SEE IF THERE IS A TREND ALONG THESE LINES.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THERE WAS LITTLE; IF ANY; STATIC NOTICED IN THE B777 COM RADIOS DURING STATIC ENVIRONMENTS AS COMPARED TO THE OLDER BOEING B727 RADIOS. RPTR WAS CURIOUS IF THE STATIC DISCHARGES WERE SIMILAR TO DIRECT CURRENT (D.C.) DISCHARGES AND WHETHER OR NOT THE INCREASED USE OF CARBON FIBER IN ACFT CONSTRUCTION; CONTRIBUTES TO SOME TYPE OF INCREASED IONIZATION THAT AFFECTS THE SEVERITY OF STATIC DISCHARGES. RPTR ALSO STATED HE NOW FLIES THE AIRBUS A320 AND HAS HAD NUMEROUS; SERIOUS STATIC DISCHARGES THAT REQUIRED HIM; ON ONE OCCASION; TO GO FROM 'ALTERNATE LAW' TO 'DIRECT LAW' FOR LNDG HIS A320 DUE TO LOSING THE ACFT'S AIR DATA/INERTIAL REFERENCE UNITS (ADIRU) AND CONTROL DISPLAY UNIT (CDU). RPTR WONDERS IF THESE STATIC DISCHARGES ARE INDUCING A TYPE OF ELECTROMAGNETIC IMPULSE OR INTERFERENCE (EMI) WITHIN THE ACFT'S CIRCUITRY THAT OVERLOAD THE WIRES AND CAUSE THE GLASS COCKPIT OR CERTAIN CDU'S TO GO DARK. RADIO COM STATIC INTERFERENCE WAS MORE NOTICEABLE ON THE AIRBUS A320 THAN ON THE B777 ACFT DURING LIGHTNING OR STATIC ENVIRONMENTS.

Data retrieved from NASA's ASRS site as of January 2009 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.