A RUAG Australia project proves SPD repairs successfully restore both the lost structural integrity and the load carrying capacity of aircraft wing panels. Winning the Best Written Paper Award in Additive
Manufacturing, at the 17th Australian International Aerospace Congress, held at AVALON
2017, reconfirms the quality contributions made by RUAG Australia in SPD technology.
Paper co-authors, Neil Matthews, RUAG Australia, and Dr. Rhys Jones, Monash University,
continue to define and lead SPD innovations.

Investigating and proving the viability of Supersonic Particle Deposition (SPD) repair technology for
structural components, in this case corroded wing skins on operational aircraft, is another industry
milestone for the internationally renowned experts, Neil Matthews, Senior Manager Research and
Technology, RUAG Australia, and Professor Rhys Jones, Head Centre of Expertise Structural
Mechanics, Department of Mechanical and Aerospace Engineering, Monash University, Victoria,
Australia.

The success also provides a more positive outlook for air forces, in terms of continued platform
performance and improved cost-savings on maintenance budgets. “This award confirms our
passion for investigating technologies which enable us to serve our customers with the best
possible solutions,” states Neil Matthews.

“Testing was performed on operational aircraft replicated structure using operational flight load
spectra. The outstanding results are specifically interesting with regards to legacy aircraft, as
corrosion related issues represent up to A$ 228 million annual spend on Australian Defence
aircraft , and at least 31% of the US Air Force’s annual maintenance costs. These are remarkable
sums and are not expected to scale-down, even with the introduction of new aircraft, as air forces
need to operate these aircraft longer, due to budget constraints,” Neil Matthews points out.

The paper, entitled ‘Additive metal solutions to corroded wing skins in operational aircraft’,
examined the use of SPD for repairs to wing elements. It proves that SPD repairs restore integrity
for external patch repairs to skin corrosion, for embedded scarf repairs, and for external patch
repairs to inhibit intergranular cracking (IGC). In fact, analysis reveals that SPD repairs on
compression surfaces where there is up to a 50% loss of material between the risers can
essentially restore the load carrying capacity of the wing, even in the case of Stress Corrosion
Cracking (SCC) in the risers.

“We became aware of the technology’s potential to restore lost structural integrity during our
successful certification and incorporation of SPD repair solutions for nonstructural applications
(geometry restorations),” explains Neil Matthews. Dr. Rhys Jones and Neil Matthews have been
collaborating in the further development for this technology in structural applications since 2008
and are considered world leaders on the subject, holding several international patents on behalf of
RUAG Australia.

SPD (also referred to as Cold Spray) is a technology in which metal powder particles are
accelerated to supersonic speeds in a high pressure expanded gas flow and impact a solid surface
with sufficient energy to cause plastic deformation and bonding with the underlying material.
RUAG Aviation is a leading supplier, support provider and integrator of systems and components
for civil and military aviation worldwide.

Servicing aircraft and helicopters throughout their entire life cycle, the company’s core
competencies include maintenance, repair and overhaul services, upgrades, and the development,
manufacturing and integration of subsystems.

RUAG is an authorised service centre for OEMs of renown, such as Airbus Helicopters, Bell,
Bombardier, Cirrus, Cessna, Diamond, Dassault Aviation, Embraer, Leonardo, Piaggio, Sikorsky,
Piper, and Mooney, as well as a service centre for 328 Support Services, Hawker Beechcraft,
Viking und MD Helicopters. RUAG Aviation is also a partner to the Swiss Armed Forces and other
international air forces.

The company is also the manufacturer (OEM) of the Dornier 228, a versatile aircraft for challenging
special missions and passenger and cargo operations.

RUAG Aviation is an approved Part 21/J EASA Design Organisation, Part 21/G EASA Production
Organisation, and Part 145 EASA Maintenance Organisation.