Balloon Life,June2000

28

REPAIR STATION

by Alan Sanderson

In the interval between annual inspections, there are several
factors that can contribute to abnormal wear or damage to your
balloon system. If you can recognize the symptoms early,you can
save yourself a lot of time and expense.

Know Your Limits
Theengineerswhodesignedyourballoonsystemhave
calculatedasetofoperatinglimitstheyhave publishedinthe
manufacturer’sflightmanual.Theselimitsincludemaximum
climb and descent rates, maximum envelope temperature, maxi-
mum gross weight for a combination of temperature and altitude
(usuallyintheformofaloadingchartorgraph),maximum
takeoff wind speed, andminimum fuel pressure.
Pay attentiontothe loading chartin the flight manual. It is
designed to prevent overloadingthat can create the need to heat
the envelope beyondthe fabric’s maximum temperature rating.
Operating the balloonabove the temperature limit will weaken
the fabric and shorten its life.
Some morning flight conditions provide ample opportunity
for overloading. If you are flying in a valley where you encounter
a temperature inversionor drainagewind,youmightloadthe
basket according to the launch site temperature and altitude. This
temperatureisabouttheminimumyouwillencounteronthe
flight asthe sunwarms the air. A temperature inversion traps a
layer of cold air under a warm layer. Drainage results when cold
air flows downhill, lifting warmer air. Once you climb to the top
of the coldair youwill be inmuchwarmer airwhere you may
exceed the temperature limit to climb any higher. Allow enough
excesslifttoclimbintothewarmerairabovetheinversion
withoutoverheatingtheenvelope,evenifitmeansleavinga
passenger or a fuel cylinder.
Sudden loss of weight, such as dropping skydivers or a hang
glider can allow the balloontoclimb at speedshigher than the
limitspecifiedintheflightmanual.Certificationflighttesting
verifies that the balloonwillperformsafely if flownwithinits
publishedlimits. If youexceedthe manufacturer’s limits in any
way,youbecomeatestpilotforyouraircraft.Ifyourflight
manual provides a procedure todrop skydivers or hanggliders,
followitcarefully.Avoidactivitiesforwhichyouhaveno
publisheddata.

ToTarp or Not toTarp
Contact with an obstacle causes some envelope damage, but
ground handling causes much of it. Stepping on fabric on a rough

surface can cause punctures and abrasions. Stepping on fabric on
a slipperysurface is unlikely to cause damage. A tarp or ground
clothprovidesa slipperysurfacethatcanprotectthe envelope
fromabrasionanddirt. Carefulattentiontocrew andspectator
activities canprevent most footprintdamage.
Handlinga tarp addseffortto the crew’sactivities. Afew
pilots always use a tarp, both forinflation and deflation. At a large
event,atarpprovidesaboundaryforthespectators.Often
spectatorswillwalkaroundatarp,butmaywalkacrossan
envelope. During cold inflationyou can reduce any abrasionon
thegroundifyouwalkundertheenvelopeandliftitwhile
spreading out each side. Walk toward the center of the envelope,
grab a gore seam or load tape, and hold it above your head as you
walk away from the center. Do this on the opposite side, until the
envelope is spreadout evenly.
If a launchor landingsite is dirty or wet, a tarp is useful. It
canprotecttheenvelopefromsagebrushorcactus,bothfor
inflation and deflation. It can serve as shelter in case of a sudden
changeinthe weather, or as a meanstodragequipmentacross
mudorsnow. For aspecialshapeor a lightcoloredenvelope,
expect touse a tarp. I amnot aware of any studies that indicate
usinga tarpadds significantly to the life of an envelope, unless
it keeps the envelope dry. I would recommend that you carry one
for the occasional situation where you may findit necessary.

Basket Floors
A basket floor can suffer several types of damage. The most
common damage is hidden until the annual inspection when the
fuelcylindersareremoved.Ifyoufindwearmarksunder the
cylinderbaserings,youshouldpreventadditionalwear.The
metalringmoves aroundonthe basketfloor, grindingdirt and
sand into the wood. This sandpaper effectshouldbe stopped as
soonas it is noticed. A slight marking is a warning, but a deeper
groove canbe the start ofa veryexpensiverepair job, ranging
froma floor replacementto a total basket rebuild.
Some manufacturers provide a plastic or metal wear surface
that can be used under the cylinders. Otherwise, you can cushion
the ring by applying a covering such as a split rubber hose or 2 to
3 layers of duct tape to the bottom cylinder ring. Keep the basket
floor cleanby removing dirt and grit from under and behind the
fuelcylinders.
Rotisanotherproblemforbaskets.Some pilotshave in-
stalled carpetinginthe basket (not recommendedbymostbal-
loonmanufacturers),andoccasionallyperformasplashand

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Balloon Life,June 2000

dash. The carpet then serves as a sponge, keeping the basket floor
wet. Dirt that is trapped behind the scuff leather also traps
moisture, allowing the edge of the floor and the bottom of the
wicker to rot. If you get the basket wet, be sure to clean out the
mud inside the scuff leather, and remove any carpetingto allow
it to dry away from the basket.

Skids, Wicker, andSuede
The skids or runners on the bottom of the basket serve to
absorb some of thelandingimpact, and to provide a layer of wood
that can be worn off before the basket floor is damaged. A tether
in ahard surfaced parking lot can rapidly wearout aset of
hardwoodskids. Some manufacturersprovidea skidcover made
of plastic or plastic deck lumber. Such materials willnot wear as
rapidly as hardwood, and are less likely to split on impact.
Wickeris not often heavily loadedduring evenadrag
landing,althoughit maysufferslight wear.Itwill survive
moderate impacts with fixed objects orsoft treetops without
damage. Much of the wear comes from transportation, where the
wicker rubs against a truck bed rail, tailgate, or a fan cage. A
basket cover ormoving pad wrapped around the wickercan
prevent such damage.
Suede is not often damaged, but it can show signs of wear.
Shinyspots on suede indicate something has been rubbing on it
for a while. A basket cover in an open truck or trailer moving in
the wind can polish off the nap. Place an old sheet between the
suede and the basket cover to prevent the polishing action – the
sheet will take the wear.
It isyour responsibilityas the pilottomaintainyour balloon
in an airworthy condition. If you have any questions about the
symptoms described above, contact your local repair station.