RFID Rides High On Jet Engines

Boeing Co. and Delta Air Lines in July will begin testing UHF passive radio-frequency identification tags on Pratt & Whitney 2037 jet engines in Delta-owned Boeing 737 planes. The companies hope to determine how well the tags hold up under the extreme conditions of an engine environment.

One engine on each of approximately 14 aircraft will have an RFID tag sealed in a ceramic capsule that's attached to the line-replaceable unit on the Pratt & Whitney engine to determine if it can withstand extreme vibrations and temperatures ranging from 900 degrees Fahrenheit to minus 60 degrees Fahrenheit. Technicians at Delta's Atlanta hub will read the tags when the commercial flights land in the evening for overnight maintenance checks.

"The next step is to get the project off the ground, so we can start this 90-day trial," says Judy Harrison, Delta's engine maintenance regulatory compliance analyst. If the tags can endure the vibrations and high temperatures, they will replace the metal plates that carry the parts information used today, Harrison says. "The next step is to tell Boeing and Airbus to write maintenance requirements for parts on the tags, and inform their suppliers of the project," she says.

Information will be encoded on the RFID tag, and also will be linked back to a database with details on warranty and part-replacement history to give the technician in the field the information quickly. The companies also will use bar codes alongside the RFID tags for supplemental information.

The test is a precursor to a mandatory tagging program that Boeing and rival Airbus SAS will require of their suppliers. The two are jointly working to write industry standards for the commercial aircraft sector because they use products from roughly 70% of the same suppliers.

The Federal Aviation Administration last week gave the OK to perform the tests on commercial flights. Approval came after a two-year trial between FedEx Corp. and Boeing. The first test, which started in November 2003, was with high-frequency 13.56-MHz passive tags from Infineon Technologies AG. The range in which the tags were read proved limiting and soon the group switched to UHF 915-MHz, increasing the range from one to 15 feet.

From FedEx's Memphis, Tenn., hub, tests were run for 90 days. Tags were placed on parts in the main cabin and flight deck on a FedEx custom cargo plane built by Boeing. In all, 40 tags were placed throughout the plane, from the flight deck to wheels to avionics and cargo compartments. Boeing selected 10-kilobit read-write RFID inlays from Infineon because they offered the highest memory capacity available at 13.56-MHz and conformed to ISO Standard 15693, which means they can be used anywhere in the world.

The inlays were converted into smart labels using Zebra Technologies' Z-Ultimate 3000 thermal-transfer media, which was further strengthened with Z-Ultimate clear laminate to provide additional protection against the fluids, vapors, and temperatures they would be exposed to inside the engine and airframe. Special backing material from Emerson & Cuming, a subsidiary of National Starch and Chemical Co., was also used on metal to provide spacing between the label and the part to prevent interference.

The goal was to identify potential electromagnetic interference, and detrimental environmental effects from changes in pressure, temperature, and humidity, as well as evaluate the ability to read and write data to the RFID tag during each scheduled inspection on the ground. "Zero failures occurred, and the planes flew 18-hour days," says Kenneth Porad, Boeing's principal engineer for reliability and maintainability. "From these tests, we will create a global enterprisewide standard for RFID-enabled shipping labels."

When the project gets off the ground, Boeing will mandate its 2,700 supplies use RFID-enabled shipping labels to support the manufacturing in its commercial airplane division. Although Delta is moving forward with this joint test, the likelihood of any widespread adoption is unclear. Skyrocketing jet fuel prices is an obstacle the airline industry will have to overcome before Delta and others agree to heavily invest in RFID projects, and that's cutting any hopes of the airline industry funding these projects in the near future, Harrison says.