Radio frequency identification (RFID) aerospace applications have attracted interest since the introduction of inexpensive passive tags. The driving factors are reducing inventory time and improving accuracy. Implementation differs, but the technology accurately and rapidly gathers identification data from individual items to determine their state. Tags can uniquely identify articles as they move along a chain of custody, cataloging a time stamp for each read event.
A compelling application for RFID is tool tracking. Aircraft maintenance providers must automatically identify the appropriate tools to take to each job and account for all tools following task completion. Rugged, mount-on-metal tags can be permanently epoxied in place. Used with a smart toolbox or tool-crib, tags can be added to or subtracted from inventory almost instantaneously. Applying real-time tool inventories aids in compliance and reduces the paperwork burden associated with mandated routine maintenance.
Check-in/check-out data for specific tools can also spot deficiencies in the operation. For example, if a high-value tool is used repeatedly in one type of operation and rarely in another, that item could be pre-positioned closer to where it’s needed. Similarly, pre-packaged job kits can be assembled and verified, reducing the churn of returning to a tool area to pick up a forgotten item.
There are largely diverse types of assets in and on an airframe: life vests, oxygen generators, seat belt airbags, avionics, electro-mechanical system components, communication equipment, and food/beverage carts. That diversity requires a range of tags from large labels (4.0" x 2.0") to small mount-on-metal tags (0.6" x 0.4").
Tagging can greatly speed documentation of routine maintenance tasks. For example, oxygen generators can be inventoried without having to open the overhead panels, saving significant time and labor.
Flyable assets represent a special challenge for RFID tagging because of the rigor of the certification. Flyable tags are regulated subject to SAE AS5678 2006-12, RTCA DO-160, and ATA Spec 2000 Ch 9 Rev 2916.1. Depending on the tag’s application, it may need to be immune to various materials and conditions such as decompression, overpressure, humidity cycling, shock and vibration, electrostatic discharge, flammability, fluid (hydraulic and deicing) immersion, solvent exposure, and temperature rating. In addition, there’s the typical read range and data retention capacity of the tag itself to consider.
Flyable tags must have an expanded memory capacity compared to standard passive RFID tags, such as those used for baggage. Aerospace tags need 2kb to 64kb, significantly more than standard RFID labels. Extended memory allows users to access maintenance or inspection data locally, without a data link to a centralized database.
Adoption of RFID technology in aerospace applications has been gradual as the technology isn’t plug-and-play. Successful implementation requires careful planning and understanding of the use case, however, deployed systems have demonstrated considerable return on investment (ROI) for users stemming from improved speed and accurate data acquisition.