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Wednesday, December 5, 2007 - 10:30 AM
Qualification and Integration of Av-Dec Antenna Gaskets on the C-17
The USAF C-17 maintainer community has requested the process for installing antennas be changed to eliminate the use of the AMS 3675 polysulfide sealing material and enable the use of gaskets under the antennas installed on the C-17 aircraft. The current use of a polysulfide sealant on external antennas has a long cure time, is environmentally unsound, permanently stains and/or ruins uniforms, and can damage aircraft surfaces. An alternate material, a gasket produced by Aviation Devices & Electronic Components, L. L. C. (Av-DEC), has been requested in lieu of the current polysulfide sealant. Boeing C-17 engineers, in conjunction with the C-17 Systems Group have developed a qualification and evaluation test plan for qualifying the Av-DEC gaskets on the C-17. The Av-DEC gaskets are being evaluated for use on fourteen (14) antennas. The purpose of the project is to obtain the laboratory test data needed to (1) show conformity of the selected gasket material to the C-17 Air Vehicle Specification and (2) show that the RF performance of the antenna subsystems modified to use the gasket is equal to the RF performance current antenna subsystem installations. The C-17 is experiencing problems with the current antenna gasketing/sealant procedure. These have been documented in Deficiency Report DR113833. A proposed solution is to replace the currently authorized AMS 3675 sealant with a precut gasket made by Aviation Electrical Devices Inc. (AvDEC). The AvDEC gaskets have found wide use on other commercial and military aircraft, but are not approved for use on the C-17. Boeing C-17 engineers, in conjunction with the C-17 Systems Group have developed a test plan for qualifying the AvDEC gaskets on the C-17. The Coating Technology Integration Office received funding to perform the test plan. The testing will be conducted in two phases. Phase I will conduct corrosion and thermal conditioning testing. This consists of mixed couple corrosion testing of coupons based upon AMS 3675 and AS 5127/1. For Phase II, radio frequency and lightning strike testing will be conducted using 14 antennas representative of those found on the C-17. This paper will discuss the testing and present the preliminary results of the ongoing testing.
See more of Corrosion Resistant Materials I
See more of The 2007 Tri-Service Corrosion Conference (December 3-7, 2007)
See more of The 2007 Tri-Service Corrosion Conference (December 3-7, 2007)