AMT_JanuaryFebruary2021 - 18

TECH SPOTL IGHT

Left, a disassembled TKS
hawker pump. Right, a
fully assembled pump.

platforms - and they work closely with aircraft OEMs to design
the deicing system specific to their need and how the aircraft will
be used.
" While the system concept is the same, the deicer boot material and/or design will differ between a privately-owned airplane
platform and a regional aircraft that will likely have high flight
hours. The aircraft OEM may also select the Collins Aerospace
silver deicer option for many business aircraft platforms due to
customer preference for a metallic look to the aircraft leading
edges, " explained Molly Stibaner, senior product support engineer
for Collins Aerospace.
Collins Aerospace's deicers consist of inflatable rubber/fabric
boots attached to the leading edge of the wing and stabilizers.
When ice begins to form on the leading edge, the boot is inflated
and cracks the ice off the leading edge, allowing the airstream to
remove the ice. A complete pneumatic deice system consisting of
the components such as valves, timers/controllers and switches
that support proper operation of the system is offered by Collins
Aerospace.
For installation, Stibaner said their deicers are glued to the leading edge. Collins Aerospace's standard deicers involve the manual
application of adhesive to the back of the deicer and leading edge
before installation. FASTboot deicers are manufactured with a
pre-applied pressure sensitive adhesive (PSA), which eliminates
solvent usage, labor and dry times in the installation process.
" The installation of a pneumatic deicer is a unique maintenance
procedure that requires proper tooling and technique. Collins Aerospace, Goodrich Deicing provides the necessary information for
success through customer training and technical support, " Jeremy

JANUARY/FEBRUARY 2021

Henry, senior program manager with the Collins Aerospace Goodrich De-icing
Authorized Service Center
Network added.
Henry said that the technology behind the company's pneumatic deice boots
hasn't changed significantly,
but their performance and
longevity have been significantly enhanced through
the use of newly engineered
materials and manufacturing methods.
" While a high percentage
of today's deice boots are still
made from the familiar black
neoprene, Collins Aerospace
Goodrich Deicing is the sole
supplier of optional boots made with an engineered polymer called
Estane, which provides more resistance to diester fluids with the
additional benefit of improved ice shedding, " Henry said.
Estane is also easier to maintain, due to the nature of the
improved material.
" In general, the maintenance processes remain consistent even
though the materials used may differ. For example, deicers require
the application of conductive edge sealer around the edges to allow
for proper static dissipation in order to prevent pinhole damage.
The type of conductive edge sealer that is used depends on the
material of the deicer, " explained Henry.
Knowing when a system needs maintenance or replacing is
easy as a visual inspection. Pneumatic deicers should be visually
inspected frequently and damage repaired immediately. Unrepaired
surface damage can lead to ingress of water into the deicing system,
ultimately creating further costly damage to internal components
such as valves and sensors, Stibaner said.
Additionally, unrepaired damage limits proper function of
the deicer itself decreasing effective ice shed. Collins Aerospace,
Goodrich Deicing offers repair kits that are specially developed
to repair damage while still allowing for the proper inflation and
ice shed of the deicer. The company also offers several products to
increase the longevity of the deicers, protecting against weathering
and ozone, for example.
However, certain damage requires replacing the deicer.
" These include cuts, tears or ruptures that extend through the
bondside fabric layer, broken stitch or thread and damaged areas
which exceed four inches by nine inches, " she said.
Stibaner added that the allowable number of repairs is:

AIRCRAFT MAINTENANCE TECHNOLOGY

AMT_JanuaryFebruary2021

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