Tech Briefs Magazine - September 2021 - 24

TECHNOLOGY LEADERS Aviation/Aerospace
obsolescence in its ARINC-717 FDAU
where the OEM no longer supported
Chassis
Power supply
Backplane
Backplane interface
Controller module
User module
Spare slot
Module top-block
the equipment. Standard COTS CurtissWright
data acquisition modules were
integrated into an ARINC-600 chassis,
as shown below (external panels have
been removed).
A modular FDAU typically contains power, control, and acquisition modules to meet custom requirements with
off-the-shelf capabilities.
These solutions often offer a modular
approach with interchangeable data
acquisition modules that can interface
with aircraft sensors and busses. These
modules can be incorporated into a custom
LRU that closely or exactly matches
the functionality of the obsolete one. A
good example of this is when a flight
data acquisition unit (FDAU) is used
with a flight data recorder (or black
box). Rather than create a new custom
unit from scratch, existing modules can
be selected to quickly meet the I/O
functionality needed.
Reverse Engineering Process
Replacing an obsolete LRU is not an
easy task. A preliminary investigation
stage will be needed to review all the
Building block
modules
Example Case Study
A customer approached CurtissWright
to provide an LRU to address
available documentation including:
* Interface control documents (ICDs)
* Functional test reports
* Environmental test reports
* Aircraft installation diagrams
* Aircraft wiring diagrams
A prototype can quickly be produced
and tested by the customer to
ensure that it functions correctly. A
full set of verification tests will be conducted
to show that all requirements
are met. This approach ensures the
customer is involved in the process
from the start right up to final production
deliveries.
The modular construction of the
FDAU was configured to closely match
the existing equipment with minimal
non-recurring work and thus a short
lead time. The result was a direct re -
placement to the existing unit with no
rewiring of the aircraft, saving considerable
cost and time.
This case study is a prime example of
how a replacement unit can quickly be
produced. A quick prototype can be
built and used by the customer to confirm
correct functionality with existing
systems, saving years of development
time.
Conclusions
Parts obsolescence is inevitable in the
aerospace industry, especially in electronic
equipment. The lifecycle of an
aircraft is much longer than the availability
of a significant number of electronics
parts and often longer than contractually
planned. This can eventually
lead to challenges repairing or replacing
aircraft parts, with serious consequences
for the fleet.
There are several approaches to try
to mitigate this obsolescence including
last-time buys, repairs, and sourcing
secondhand parts. While one of these
approaches may work, eventually it is
often necessary to use a modern re -
placement. This can be prohibitively
expensive unless a COTS solution can
be found that makes producing units in
low numbers economical.
This article was written
by
Michael
Doherty, Programs Manager, and Stephen
Willis, Marketing Portfolio Manager, at
Curtiss-Wright Defense Solutions, Ashburn,
VA. For more information, visit http://
info.hotims.com/79417-122.
Quick access
recorder
Optimized for weight
and heat dissipation
An existing COTS solution was quickly reformed to meet a specific customer form factor.
24
Cov
www.techbriefs.com
ToC
Reference
1 Reed, S. (2010), " The role of R&D in
support of the UK MOD's fleet of ageing
aircraft " , AA&S 2010, May 2010. Retrieved
from www.meetingdata.utcdayton.com/
agenda/airworthiness/2010/proceeding/
presentations/P3331.pdf
Tech Briefs, September 2021

http://info.hotims.com/79417-122 http://www.meetingdata.utcdayton.com/agenda/airworthiness/2010/proceeding/presentations/P3331.pdf http://www.techbriefs.com http://www.abpi.net/ntbpdfclicks/l.php?202109TBNAV

Tech Briefs Magazine - September 2021

Table of Contents for the Digital Edition of Tech Briefs Magazine - September 2021