Know-it-all labels

Coast Guard aims to track every aircraft part ' in inventory or in service

The Real things: Coast Guard investigator analyst Terry Boyce says the problem of black-market aircraft parts becomes more acute when the economy goes down.

WPN photo by Rich-Joseph Facun

The Defense Department, NASA and the Coast Guard are embarking on an ambitious program to put a unique identifier on every critical aircraft part.

Being able to identify and track every part in service and in inventory has obvious advantages for logistics management, and DOD has begun requiring suppliers to provide unique-identifier markings on parts. But the Coast Guard's interest in unique identifiers stemmed from law enforcement concerns rather than logistics, said USCG investigator analyst Terry Boyce.

As an investigator, one of his major concerns is black-market aircraft parts ' counterfeit or other nonserviceable parts that can illegally find their way into operational aircraft.

When it occurs, it can pose serious safety problems.

Boyce needed a method for identifying and tracking the millions of parts documented in USCG's Aviation Materiel Management Information System.

As he searched for a unique identifier, Boyce became the project lead of the USCG's Aircraft Repair and Supply Center Safety Critical Part Marking Program and an evangelist for 2-D bar coding.

USCG has experimented since 1996 with DataMatrix 2-D bar codes, initially applying the codes with durable labels. Since 2002, it has been experimenting with more permanent markings applied directly to parts. This year, it awarded a contract to integrator Intermec to design, build and test a self-contained mobile marking system that can apply both labels and laser-etched bar codes. It expects the system to be tested and in production by the end of the year.

DataMatrix is an International Standards Orgainzation bar coding standard that can contain the alphanumeric characters of a unique identifier in a symbol only a couple millimeters across. It can be expanded to increase its data capacity.

Larry Huseby, director of business development for Intermec's public-sector division, estimated that as many as 80 percent of the Coast Guard's parts could be successfully marked with labels. There are a lot of methods to address the remaining 20 percent, but finding the right one can be difficult.

Possibilities include printing or stenciling the bar code; dot peening, or hammering the code into the part with a series of dots, much like a dot-matrix printer; etching it in chemically; or using a laser either to burn it in or to bond a coating onto the part.

Each method has drawbacks. Printed or painted marks can be covered by painting or removed during refurbishing. Dot peening stresses the part and can be difficult to do accurately.

A laser can burn the metal and change its metallurgic characteristics.

'The test we are taking on is to use the safest technology we can in the greatest number of cases we can,' Huseby said. 'What we have settled on is a CO2 laser, which is not hot enough to melt metal.'

The technique is not perfect. 'There are some parts where this won't work because you can't put any coating on the part,' he said.

Direct marking also offers more challenges in reading the bar codes than labels do. Labels typically have high-contrast black-on-white markings that are easy for a device to read. Direct markings are likely to have lower contrast and different light refraction and require more sensitive readers.

Boyce said that in real-world tests, both the applied labels and the direct markings showed remarkable robustness. Labels installed in 1997 on 500 parts for HH-65 Sikorsky Sea Guard helicopters remained in good condition even on rotors exposed to the elements. In 2002, several kinds of permanent marking were tried on parts for the HH-60J Jayhawk medium-range recovery helicopter, HC-130J maritime patrol aircraft and HU-25 Falcon jet. All markings remained in good condition and were readable even after more than 90 hours of flight and refurbishing.

Reader Comments

Please post your comments here. Comments are moderated, so they may not appear immediately after submitting. We will not post comments that we consider abusive or off-topic.

Please type the letters/numbers you see above