Download extending the life of aging military platforms with electronic sensors

EXTENDING THE LIFE OF AGING
MILITARY PLATFORMS WITH
ELECTRONIC SENSORS
Sherborne Sensors Whitepaper
January 2015
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Extending the life of aging military platforms with electronic sensors
The life expectancy of aging military platforms can be extended significantly using
customized high-performance electronic sensors.
Today’s military platforms are expected to remain longer in service partly due to cuts in
defence spending in Western nations. The rising cost of new weapon systems
juxtaposed with the need to ensure mission capability and effectiveness has made the
maintenance of aging military fleets a global concern.
Many fleets of aircraft, land vehicles and naval vessels are being kept in service well
beyond their original design service lives – either in terms of age or usage, and
sometimes both. This requires a robust strategy and is achieved by extensive
remanufacture and upgrading of components, not only to maintain availability and
reliability, but to improve their capability and superiority.
Yet the sourcing and manufacturing of replacement parts is a serious issue facing
system owners. This is particularly the case with regards to replacement of many types
of electronic sensors that provide essential data for mission-critical communications,
guidance, structural health and navigation systems.
Frequently, platform owners need to source form, fit and function replacement parts that
can be installed without any modification to the existing systems. However, it is often
the case that replacement components are no longer available, because the original
manufacturers are no longer in business, or are not interested in supplying relatively
small quantities for spares purposes. In scenarios where the original manufacturers are
able and willing to supply them, the product price is driven upward due to the smaller
order quantities. Nevertheless, there are specialist firms that can offer customized, costeffective products based on field-proven and pre-qualified components.
Extending life
Aircraft can be sustained almost indefinitely through modernization and maintenance.
The iconic B-52 operated by the US Air Force (USAF), for example, first flew in 1952
and entered military service in 1954, while the F-5’s initial flight took place in 1963. Both
continue to fly missions today. Indeed, the current USAF fleet is the oldest in its history,
with the average age of aircraft being 26 years.
In 2005, the USAF initiated a four-year program to upgrade the B-52’s communications
system, its first major upgrade since the Kennedy Administration. The upgrades
included software and hardware, such as the ACR-210 Warrior (beyond-line-of-sight
software compatible with radio and able to transmit voice) and LINK-16, a high-speed
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digital data link for transmitting targeting and Intelligence, Surveillance and
Reconnaissance (ISR) information.
Boeing B-52H Stratofortress
In the UK, the Royal Air Force (RAF)
operates several fleets of aging aircraft,
including the C-130J Hercules and the
Tornado multi-role combat aircraft.
Jointly developed by the UK, Germany
and Italy under a collaborative
agreement and manufactured by a
consortium of BAE Systems, Airbus
Group (formerly EADS and DaimlerChrysler Aerospace) and Alenia
Aeronautica under the name of Panavia,
the Tornado GR1 entered service in 1980.
Upgrading performance
The Tornado has been the principal strike weapon employed by the UK, Germany and
Italy for more than three decades. The Mid-Life Update (MLU) program that took place
between 1998 and 2003 has been vital to ensuring the aircraft’s longevity. At a cost of
£943 million ($1.5 billion), the MLU program saw 142 Tornado GR1s upgraded to the
GR4 standard, with advances in systems, stealth technology and avionics.
Royal Air Force Panavia Tornado
Compared to the Tornado GR1, the GR4
has a Forward-Looking Infra-Red (FLIR),
a wide angle Head-Up Display (HUD),
improved cockpit displays, Night-Vision
Goggle (NVG) compatibility, new avionics
and weapons systems, along with
updated computer software. The GR4’s
upgraded navigation systems include
Global Positioning System (GPS), BAE
Systems TERPROM digital terrain
mapping system and Honeywell H-764G
laser Inertial Navigation System (INS).
The upgrade also re-armed the Tornado with the Storm Shadow missile and new
sensors including the RAPTOR and Vicon reconnaissance pods, complemented by an
improved Thermal Imaging Airborne Laser Designator (TIALD) targeting pod. A
separate program covered an integrated Defensive Aids Suite, consisting of the radar
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warning receiver, Sky Shadow radar jamming pod and BOZ-107 chaff, and flare
dispenser.
Such performance upgrades can be
employed successfully across all military
defence platforms. In Australia, for
example, BAE Systems upgraded 433
M113 army personnel carrier vehicles in
a project that spanned a decade. The
original M113 was active during the
Vietnam War; its upgrade has made it
faster and more reliable, with improved
firepower, protection and habitability.
M113 armored personnel carrier.
Sustainable strategies
A major issue with extending lifecycles of military platforms is that the original strategy
for sustainment and replacement, based on the original projected life, becomes
redundant. Manufacturers move on to the latest technologies, products and services,
such that they can no longer supply original parts for replacements.
In the case of aircraft, engineers resort to cannibalizing parts from other aircraft due to
an inability to source parts, either permanently grounding the aircraft or rendering them
no longer mission capable. This naturally affects the fleet’s Aircraft Availability (AA)
statistic – a measurement employed by the USAF to denote the percentage of each
aircraft model that is mission capable (the typical USAF AA rate is 70 percent).
As systems age, more frequent breakdowns from system failure or cannibalization
result in longer repair times, higher workloads for engineers and contribute to
decreasing a fleet’s AA percentage. The 1988 disaster of Aloha Flight 243, when a 19
year-old Boeing 737 lost a major portion of its upper fuselage in flight, brought
awareness of ageing aircraft and the need for enhanced maintenance regimes in the
aviation community. It also catalyzed the creation of the 1991 Aging Aircraft Safety Act.
Maintenance cycles
Military equipment ages in two basic ways: obsolescence in hardware or software that
renders the equipment insupportable and inadequate performance that renders the
equipment unable to fulfil its mission. There also are two distinct types of aging:
chronological and cyclic. The former is driven by factors such as system obsolescence,
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corrosion, environmental damage and general wear. The latter is determined by the way
the aircraft, vehicle or vessel is operated and includes fatigue, thermal and stress
damage.
Both chronological and cyclic events affect the rising cost of maintaining an aging fleet.
Aging can cause flaws to develop earlier than predicted in the original strategy for
replacement of parts, and extended usage can accelerate their growth. Aggressive
environments can also accelerate the development of flaws faster than what was initially
predicted.
To counter this challenge, the USAF uses Advanced Component Obsolescence
Management (AVCOM) software to predict the future usage of a particular part and
assess obsolescence early on in the maintenance and supply process. Another method
to assess proactive resolution of component issues is the Demand Forecast Accuracy
(DFA) equation. DFA compares the actual demand with the forecast demand predicted
at the beginning of the year. Forecasting is calculated as: DFA = 1 – Σ [(Actual demand
– Forecast demand)/ Σ Actual demand].
However, the DFA input data isn’t always accurate. Sometimes the prediction is so high
that it doesn’t illustrate which parts were actually used or needed. At times, the wait for
parts is so long that companies decide to source parts by cannibalization and not order
them at all. These alternative choices invalidate the data and render the prediction as
unreliable.
Maintenance cycles based on the fatigue
life of structures or the mean time
between failures are determined through
rigorous testing. Maintenance cycle
inspections are therefore timetabled
regularly to ensure safety, and parts are
replaced or repaired accordingly.
Maintenance includes repair,
remanufacture and component
Examples of accelerometer sensors used to extend
the life of ageing military platforms
replacement (form, fit and function
replacement due to obsolescence). The
USAF implements two major strategies for maintenance work: Condition Based
Maintenance + Prognostics (CBM+) and Reliability Centered Maintenance (RCM). The
former performs maintenance based on evidence from sensor data or off-line trend
monitoring. The latter uses reliability tools and techniques to schedule maintenance to
balance safety, schedule and risk by considering the probability of parts failure.
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Sourcing challenges
Although the financial benefits of robust maintenance and upgrade programs are clear,
defence organizations face significant hurdles in their implementation. The sourcing of
essential spares is a serious issue facing system owners, particularly in relation to
Maintenance, Repair and Operations (MRO) services, often because spare parts are
out of production.
Given that many military platforms may be decades old, common scenario are that the
original manufacturers have either gone out of business, been absorbed into larger
companies, or demand for the required parts is not sufficient to be of commercial
interest to the supplier. Subsequently, there are unique issues for sourcing parts that
both fit the aging platform model and conform to contemporary quality standards – for
example, attempting to integrate a digital system into a platform built in the analogue
era.
Maintaining existing systems also is becoming increasingly difficult to balance with
budget cuts, inventory specifications and changing mission requirements. Moreover,
while maintenance manuals for these aging platforms may still exist, precise instructions
about the electronic systems they employ may be difficult to find. This is why it is
essential to work with a supplier with proven specialist knowledge and expertise in
system delivery.
There also is tension within the market of manufacturing and supplying spare parts
between Original Equipment Manufacturers (OEMs) and Parts Manufacturer Approvals
(PMAs), together with the consolidated pools of acceptable contractors. This is due to
the level of competition that exists between OEM and PMA companies for contracts.
Both options have their pros and cons. OEM parts are guaranteed to be compatible with
the machine because they are an identical replacement part. OEMs also are
increasingly focused on MRO services partnerships, which is particularly beneficial to
the aeronautical industry, where maintenance and performance is crucial to fleet
optimization.
On the other hand, PMA parts are developed separately by an independent
manufacturer but still retain the same design characteristics as the OEM product. They
have to be approved by the corresponding authority, and regulations typically mandate
that PMA parts must be as good as or better than the OEM counterpart. PMA
manufacturers must also demonstrate the value of their product to the client – through
price, lifecycle, efficiency or availability.
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Proof of concept
A previously unforeseen element of competition between OEMs and PMAs is currently
being played out with regards to the USAF F-35 program, known as ‘Joint Strike
Fighter.’ The USAF and US Navy (USN) have approximately 3,500 fighter aircraft, many
of which are more than 20 years old. An initiative began in 1996 to replace the majority
of the inventory with 2,443 new F-35s.
Lockheed Martin won the $200 billion defence contract. However, the project has been
plagued with delays to the delivery schedule, while the cost has increased significantly.
As of November 2012, it was 42 percent over the baseline budget predicted in 2007,
with the cost of the unit doubling since development began in 2001.
In summer 2013, Boeing responded to
its competitor’s predicament by pitching
an upgraded model of the F/A-18 known
as the ‘Advanced Super Hornet’ to the
USN as an alternative to the F-35 model.
Boeing argued that it was not trying to
replace the F-35, but simply giving the
USN more solutions.
Regardless of Boeing’s intentions, the
company’s strategy is proof that existing
aircraft performance can be
F-35 A Lightning
reinvigorated with the modification and
replacement of parts at significantly lower cost than designing, developing and
manufacturing the next generation of aircraft. The F/A-18 currently costs $55 million,
whereas the F-35 is approximately $110 million.
Lockheed Martin asserts that its aircraft is a fifth generation stealth fighter jet with
superior computing power, and it cannot be compared to existing ‘rivals.’ Boeing, on
the other hand, maintains it has delivered more than 600 models on schedule and within
budget, and that it will be cheaper to maintain than the F-35. According to the
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Government of Accountability Office
(GAO), the F/A-18 costs $15,346/hour
to fly, as opposed to the USAF’s official
target for operating the F-35 at
$32,500/hour. Boeing has already sold
dozens of F/A-18s to the Royal
Australian Air Force, which was once
committed to the F-35s but gave up
waiting for it to be delivered.
FA-18 Hornet
Technical complications
The USAF F-16s and USNF/A-18s highlight the difficulties faced when designing and
testing parts for aircraft. Due to the technical complications of the F-35 program, the US
military decided to allow BAE Systems to upgrade 300 F-16s and 150 F/A-18s by
extending their lifecycles through the Service Life Extension Program (SLEP) and a
Combat Avionics Programmed Extension Suite (CAPES).
The replacement parts include electronics upgrades such as the electronically scanned
array (AESA) radar, a new Terma ALQ-213 electronic warfare system, an integrated
broadcast system (IBS) and a center display unit (CDU). The upgrades will add 2,000
flight hours to the F-16s, which translates to six to eight years’ service years, and 1,400
flight hours to the F/A-18s, which equates to an extra five years’ service years.
However, the F/A-18 was manufactured in the 1970s and the original model had a
6,000 flight hour design limit, whereas the latest upgrades will extend the total flight
hours to over 9,000, a feat that is almost unheard of for tactical jet aircraft. Additionally,
the aging Super Hornet fleet is averaging about 330 flight hours per year, which means
it’s consistently about 30 percent above planned usage. This inevitably threatens the
integrity of the aircraft structure, regardless of avionic superiority.
Electronic sensors
Sensor devices are employed in many diverse defence applications, both in the control
of larger systems and in providing raw data upon which the system will act. Sensor
deployments in significant military applications include fire control systems, naval
communications and vehicle systems.
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The long design and development cycles of military equipment can mean the sensors
employed may be considerably out of date by the time they enter service. Yet without
the sensor input, many critical systems will be rendered non-operational.
Given the rapid pace of development in sensor technologies, sourcing sensor
replacements for use in aging military platforms can be extremely difficult. It is essential
that any replacement sensors found are compatible in form, fit and function with the
original product. They should also be manufactured by a high quality organization that
understands the requirements of military systems, and by one that has the relevant
approvals.
Frequently, commercial sensors currently in production are incompatible with the
originals, demanding modifications to the system to accommodate them. This increases
cost, lead times and technical risk. Moreover, the reliability of the sensors’ performance
over many years is absolutely paramount in harsh operating environments. Therefore,
sensors must be precise, robust and environmentally protected to withstand the rigors
of military applications.
Sensor replacement in aging systems
is just one of the issues facing
maintainers of military platforms, but
it’s one that needs particular care
when selecting a compatible product.
Companies that provide custom
replacement sensors tend to be small
and specialist, and may also be
difficult to track down. By using its
experience and niche expertise, the
Examples of inclinometer sensors used in extending
the life of ageing military platforms
right company can ensure the supply
of sensors that are truly form, fit and
function replacements for older devices long out of production.
About Sherborne Sensors
Sherborne Sensors is a global leader in the design, development, manufacture and
supply of high‐precision inclinometers, accelerometers, force transducers and load
cells, instrumentation and accessories for military and aerospace and civil engineering
and industrial customers. Products are supplied under the AS9100C Quality
Accreditation, and are renowned for their ultra‐reliability and long‐life precision within
critical applications. The acquisition of synergistic technologies by Sherborne Sensors
within its product portfolio has allowed customers to benefit from expanded product
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lines, with added benefits of engineering support, global sales presence, repair,
refurbishment and calibration services, stocking programs and continuous product
improvement.
Custom Products
Sherborne Sensors actively supports a substantial infrastructure to design, develop, test
and deliver customized sensor products and systems across all of the market areas we
serve, including custom inclinometers, custom accelerometers and customized load
cells. This includes our own in-house specialists in mechanical prototyping, electrical
circuit design, sensor packaging and accessory design and integration.
We welcome opportunities to design and evaluate solutions that modify our existing
products, or require a completely new sensor, built around our proven inertial sensor
elements. We are very adept at not only designing robust, accurate and repeatable
products but also doing so in a cost effective and timely manner. An example of a
specific product that we have designed to fulfil a need where the original component is
no longer available, is a precision accelerometer to MIL-PRF-83174. These are still
used extensively in older military aircraft, providing essential information pertaining to
the structural health of the airframe.
Recognizing that design features of a sensor may at times enhance certain specification
capabilities at the expense of others, we invest significant effort in consulting with our
customers to completely understand their custom requirements, and convey our design
recommendations in a comprehensive offering.
USA & Canada
Rest of the World
PO Box 115, Wyckoff, NJ 07481-0115, USA
1 Ringway Centre, Edison Road, Basingstoke,
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Tel: (201)258-4647
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Tel: +44 (0)870 444 0728
Fax: +44 (0)870 444 0729
Email: [email protected]
and [email protected]
Email: [email protected]
and [email protected]
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