LISI AEROSPACE
fasteners
NEW
FUSELAGE INSULATIONBLANKET
RETAININGCLIPS
To ensure comfort and safety in case of fire outside the passenger cabin,
aircraft fuselagesare fittedwith thermal andacoustic insulationblankets.
These blankets are retained by means of fastener points and clips
which secure them to the framework and stiffeners of the structure. LISI
AEROSPACEhas supplied this typeof part formany years, notably for the
Boeing737series.The re-engineeringexerciseundertakenby thedivision’s
teamshasmanaged tooptimizeboth themassand thecostof these
clips. The improvement achieved is in the order of 13% of cost
andover15%of themass.This typeofexercise,whichdoesnot
involve the introduction of new technologies, demonstrates
thesavings thatcanpotentiallybeachievedonexistingparts. It
dependsbothoncritical analysisof requirement levels, carried
out with our customers, and on questioning the development
processes, made possible thanks to good understanding of our design
tools.
-20
kg
ThenewgenerationofPULL-STEM™
fastenerssaves20kgoneach
aircraftand fivehoursduring the
assemblyphases.
-15
%
Aweight saving of 15%
and a cost saving of 13%
for these new fastener
systems.
FASTENERS
PULL-STEM™
LIGHTNINGPROTECTIONSYSTEM
The issue of assembly of composite structures vulnerable to
lightning has, since 2008, beenmajor area of research for LISI
AEROSPACE. Following the launch of the STL™ lined product
family, speciallyadapted for restrictedaccess zones, LISI teams
have continued to expand their skills in this area to generate
other alternative technologies. This investmenthasallowed the
development of a combination of partial coatings, with both
increased interferenceandgoodconductivity, to respond to the
constraints of a lightning strike. This concept was chosen for
thewingsection / fuselage junctionof theA350, oneof themost
critical zones of anaircraft. Part of thePULL-IN™ / PULL-STEM™
family of fasteners, this innovation replaced the double cap
systems,whose functionwas tocontain theelectricaldischarges
associatedwithlightning.Bycircumventingtheproblemupfront,
thesolutionproposedbyLISIAEROSPACEavoids theadditionof
supplementary protectionmeasures. This system allows a gain
of20kgmass foreachaircraftbuilt,anda timesavingofover five
hours for theassemblyof this junction.
LISI 2014
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