Jun 17, 2013Commercial airplanes must undergo a number of daily, weekly and monthly maintenance checks to ensure they're flight-ready. These manual checks include inspection of life vests, oxygen generators and other loose emergency equipment in an aircraft's cabin—a process that is labor-intensive and costly.
Before a plane's first flight each day, for example, airline personnel must confirm the presence of life vests under seats (unless the plane uses seats as flotation devices). Another inspection, to verify the integrity of life vest security seals, a theft deterrent and antiterrorism measure, is typically conducted before every flight on aircraft operating within or flying internationally into the United States. Inspections to verify the serviceability of life vests are performed every few hundred flight hours or every several months, during what the Federal Aviation Administration (FAA) refers to as A-checks or C-checks. For these inspections, maintenance personnel must remove every life vest from its container to check its expiration date. On a wide-body airplane, this task can take an entire 8-hour shift.
In spring 2012, Boeing introduced its RFID Integrated Solutions program, designed to automate maintenance tasks on emergency equipment, as well as to track and manage other aircraft items and components. Boeing has been working on developing RFID-based maintenance capabilities for a number of years, and the final step was for the FAA to certify that RFID tags can serve as the authoritative source for maintenance compliance requirements, such as confirming the inspection of onboard emergency equipment. The program also has gained preliminary acceptance by the Japan Civil Aviation Bureau, General Civil Aviation Authority of the United Arab Emirates and the Civil Aviation Authority of Singapore.
"With the maintenance program we built, we now can use RFID data as a trusted source of information and sign off on maintenance task cards using that data in the form of an 'as-flying configuration' report generated by the RFID system," says William "Phil" Coop, Boeing program manager.
RFID Integrated Solutions, designed to be integrated into an airline's overall maintenance program, promises to reduce the cost of aircraft maintenance. Manual checks for life vest presence, security and serviceability are performed independently, for example, and conducting all those tasks on a wide-body aircraft could take 10 or more labor hours. With the Boeing solution, an airline can use one RFID-enabled process to perform presence, security and serviceability checks independently or simultaneously. It would take only a few labor minutes to conduct all tasks simultaneously, Coop says. Boeing's conservative estimate is an 85 percent lead-time reduction, though the company says it's typically better than that.
Securing FAA Approval
Getting to this point wasn't easy. Boeing began investigating RFID in the late 1990s, and since 2003 the company has been using the technology to track parts during the manufacture of commercial aircraft. In 2004, Boeing and Airbus, the two major commercial airplane manufacturers, teamed up to develop standards to use RFID to mark individual parts and keep maintenance records on RFID tags. They believed RFID could deliver benefits to the entire industry—airplane manufacturers could improve operational efficiencies, and airlines could reduce the time it takes to repair and maintain planes. In 2007, Boeing teamed with Japan Airlines (JAL) to demonstrate that RFID could speed the inspection process of oxygen generators onboard a 777 commercial airline.
Then, in 2008, the FAA issued its Advisory Circular (AC) 20-162, which approved the use of passive tags on planes as long as they were not interrogated in flight or when an aircraft is on an active runway or taxiway, but nixed the use of data derived from RFID tags as the authoritative source for maintenance compliance requirements. At the time, much of the RFID industry was focused on developing tags and applications for the retail sector, and the FAA did not think that technology was robust enough to serve as a guideline for the airline industry.
When Boeing conducted the JAL tests, the company says it wasn't considering an aftermarket application, so it never went to the FAA for anything more than general guidance, which came in the form of AC 20-162. In 2010, based on the FAA circular and additional regulatory guidance, Boeing partnered with Fujitsu and other RFID providers to develop a complete turnkey infrastructure, including passive ultrahigh-frequency RFID hardware, middleware, software and integration. The hardware selected specifically for its effectiveness in the aircraft environment includes Fujitsu high-memory RFID tags and Motorola Solutions MC 919OZ handheld readers.
To demonstrate operational survivability in the tough circumstances that can characterize airline industry maintenance environments, Boeing put the RFID tags and readers through a battery of tests—first in a lab (it soaked the tags in acid), then in the Mojave Desert (to ensure reader performance for all global frequencies), and finally in flight and at an Alaska Airlines maintenance base in Seattle. "We ensured our processes and procedures have safeguards to say in what circumstances this technology should not be used," Coop says.
Boeing modified the UHF RFID tags with a special coating, an encapsulation Coop says guarantees a life expectancy of 12 years under normal operating conditions. That helped allay concerns about deterioration after a couple of years that could lead to unreliable data recordings. "Things like that that we put in the maintenance program drove the FAA to accept our proposal," Coop says. "Boeing also provided a very comprehensive plan to ensure the integrity of the program, of the data, of the integration and methodology for use by our customers."
Providing Customer Service
Boeing plans to provide its RFID Integrated Solutions customers with kits to retrofit their aircraft, either on their own or using the airline company's third-party maintenance, repair and overhaul (MRO) facilities. The company also will provide clients with a set of maintenance processes to follow and will train operators who will be using the technology for conducting inspections. The RFID program includes technology oversight and management of the solution and processes for the life of the customer's contract. "We work with [the client] to not just manage what we sell up front but to continuously improve it as well and integrate new features," Coop says. "We become a partner with the airline to maximize its use of the product and keep everything safe and on the leading edge."
The program is designed to be fleet-agnostic. Boeing has demonstrated the service for airline customers with Boeing 747s, 777s, 717s and 737s, as well as Airbus A330s, A340s and A380s. The company says it will conduct an engineering assessment before launching the service with a customer to identify every anomaly in a plane configuration that might demand system design changes; there's a 5 percent to 20 percent variation from fleet to fleet, Coop notes.
Customers in Australia, Singapore and Taiwan are piloting the program and have outfitted some of their aircraft with RFID. But until an airline's full fleet is RFID-enabled—and the program is granted final acceptance by their country's regulatory authority—airlines must continue performing manual inspections as well, as part of a bridging program. "Airlines must maintain that until their last plane is retrofitted and returned to service," Coop says. It takes 12 to 18 months to retrofit a fleet of 100 planes. Following the fleet retrofit, airlines must maintain their manual processes as a backup for automated RFID data collection in the event of system failures.
The RFID Integrated Solutions program includes five applications. Most customers seem interested in beginning by using RFID to manage life vests, oxygen generators and other loose emergency equipment in an airline cabin, Coop says. For the emergency equipment management application, Boeing uses primarily 512-bit to 1-kilobyte RFID chips to store configuration, presence, security and serviceability data that may include part and serial numbers, manufacture date, expiration date and location on the airplane.
Once customers gain trust in the system, they can extend the deployment to another interior management application that focuses on items such as seat covers and linens, as well as large bulk items that are tracked in and out of the cabin. There also are two component management applications: One tracks rotable parts—airplane components that are removed for overhaul at a certain point in their maintenance life cycle and then installed in another plane. The other tracks repairables—components that can be fixed several times before they are retired. An airframe degradation management application is designed to track data about major components' structural repairs. Boeing uses high-memory RFID tags, ranging in capacity from 8 kilobytes to 4 gigabytes, to store point-of-use life cycle data about a part, component or section of the airplane, including its pedigree and identity, changes in configuration, identity or characteristics (such as hazardous materials or weight), and maintenance history, such as actions taken and conditions noted.
Enabling Just-in-Time Inspections
Another benefit of the RFID Integrated Solutions program is that it allows airlines to manage assets just in time rather than just in case. Take, for example, oxygen generator emergency equipment inspections, to calculate likely expiration timeframes. These inspections are typically conducted roughly every 18 months during C-checks, when a plane is in a hangar and entirely open. "It's a very labor-intensive task, requiring significant access to the installations through multiple access panels in the aircraft cabin," Coop says.
The inspectors calculate when the generator will expire. If the expiration date falls within a few months of the next C-check, the generator may be replaced to ensure it does not remain in service beyond its allowable service life. Coop calls this an expiration "safety net." Sometimes, the process leads to the disposal of generators that could remain in service for some time. "If you do your inspection of oxygen generators during heavy checks only, you wind up removing generators with about 20 percent of their life remaining, simply because the next heavy check is far enough away that the generator will expire before then," he says.
With Boeing's RFID system, oxygen generators can be inspected "without disturbing anything," Coop says. Once the data is captured and contained in the operator's back-end maintenance planning system, "we know exactly when each of those assets will expire," he adds. Oxygen generator replacements can be managed individually on a just-in-time basis during line-maintenance activities, rather than during base-maintenance C-checks. "This puts value-added capacity back into the C-check and makes use of often underutilized aircraft down-time on the line," Coop says. In addition to extending the generator life cycle by 20 percent, it can also reduce oxygen generator inventory by more than 50 percent.
"Once the system is in place, airlines can maintain their same routine schedules for performing inspections and just get them done quicker," Coop says. "And once they have established a good rhythm and reliability metrics, they can start to minimize some of those tasks."
Ensuring Trust
The logical next step beyond maintenance execution, Coop says, is to use accumulated RFID data for deeper maintenance planning and scheduling events. Boeing would like to make it possible to do away with routine emergency equipment inspections by building a robust back-end system that provides an alert when a component needs attention. "If we can build processes and inspections around only what is absolutely necessary, and then let the system tell us when anything else needs to happen, we can drastically minimize the number of inspections an airline has to do," Coop says.
Boeing also envisions extending the system to provide chain-of-custody and supply-chain visibility. It's not uncommon, Coop says, to see roughly half of any airline's supply parts inventory virtually unaccounted for, and if you don't know what you have, you don't know what you need. "I know if I have 100 components of a certain part number—can I use the data at any given time to tell me what those parts are doing?" he says. "Are they giving me value-added time or are they sitting in a queue, in transport or in storage?" Determining what's actually on hand and where, and eliminating unnecessary purchases, he says, could save some airlines billions of dollars.
Meanwhile, Boeing is working with the FAA to develop a framework for other organizations that want to develop their own RFID-based maintenance programs. The FAA is expected to release an operational suitability report using Boeing's RFID Integrated Solutions as a model for technical due diligence. The report will help companies understand the RFID fundamentals without divulging specifics about Boeing's approach, or, as Coop describes it, "the basic requirements that will need to be met—the 'what'—but not the secret recipe for success—the 'how to'—developed by Boeing.
"There are some companies out there right now that would like to believe this is like Walmart, that you can use cheap, throw-away tags like those used to control inventory in the retail or shipping industries and go put that on parts and suddenly everything is great," Coop says. "But Boeing wants to make a strong statement, supported by the FAA AC 20-162 advisory circular and upcoming operational suitability report, that it is not that easy and there cannot be a pennywise, dollar-foolish approach. At the end of the day, failure is not an option. These systems must be accurate and dependable."