Because corrosion and mechanical forces, such as continuous vibration, can severely damage aircraft structures over time, RNLF operators were forced to repair and replace the helicopter structure. Chafing was discovered on floor structural beams, and paint was worn away to expose bare metal. These instances alone set the conditions for continued wear and corrosion, but matters worsened when operators also discovered similar chafing on engine cowlings and various access panels.
Backed by decades of proven performance in defense applications, the RNLAF entrusted Gore’s engineers to install GORE® SKYFLEX® Aerospace Tapes, 110 and 700 Series, to the panels and structure of each helicopter. We took the following steps:
- Before installation, the structures and surfaces were cleaned.
- Gore’s 700 Series tape was applied to the floor beams, engine mounts and cowlings at key panel contact surfaces. This would prevent chafing caused by vibration on panels, mounting surfaces and other areas.
- Gore’s 100 Series tape was applied to floor panel mating surfaces along the panel perimeter.
- Thorough flight testing was conducted through normal operational use.
The results of extensive flight testing confirmed that the RNLAF made the right choice when selecting GORE SKYFLEX Aerospace Tapes, 110 and 700 Series, for its Boeing CH-47 Chinook helicopters. The expanded polytetrafluoroethylene (ePTFE) that comprises Gore’s tapes effectively sealed and protected the underlying helicopter structure, with Gore’s 110 Series installed on floor panels remaining serviceable after 400 flight hours. Results also showed positive outcomes regarding Gore’s 700 Series tape, including:
- Although discolored, the tape remained intact and functional on engine mount structures.
- The tape installed on engine access doors, cowling contact areas, aft pylon canted deck covers and transmission access panels remained intact and effective after 400 flight hours.
- On engine inlet D-ring cowlings and contact areas, the tape effectively absorbed friction and wear from contact with the panels.
- The tape on upper engine inlet screen assemblies was still serviceable after preventing cowling wear.
- Durable protection against chafing was evidenced on access panels and panel mating surfaces.
- On the mounting surfaces for the forward transmission drip pans, the tape remained intact without damage to the panels or structures.
“In this application, Gore’s tapes provided a protective barrier by reducing friction and preventing damage to the underlying helicopter structure,” says Ross Livington, Gore Product Specialist.
Due to their effectiveness, the RNLAF installed Gore’s tapes to other comparable structures throughout the helicopter and achieved similar results during operational use. In addition to decreasing the RNLAF’s labor, downtime and lifecycle costs, future tape applications should take significantly less time, as protection can be restored by simply replacing the damaged portions.