PROGRAMS

FAA PROGRAMS FOR FY2004

Full-Scale Fuselage Testing and Damage Tolerance
The characterization of damage and its effects on sandwich structure has been investigated over the last several years. This work has identified a number of characteristics of damaged states of sandwich composites. These tests were performed on coupon and element level specimens. The development of the complete understanding of these characteristics requires a full-scale test to assure that the conclusion drawn from the lower level testing applies at the panel level. This will directly support new programs in transport aircraft and continued general aviation programs utilizing sandwich structure.

Adhesive Joint Characterization and Testing
This work will identify characteristic responses of bonded structure to real-world manufacturing and repair defects. The work will also establish minimum requirements for adhesive and process controls for bonded structure. In addition, it will identify characteristics of variable bondline thickness in typical structures. A simplified test procedure to determine design and analyses parameters will also be investigated. This program dovetails into a major FAA effort to produce guidance material and policy on adhesive bonding.

Chemical Characterization of Resins and Adhesives
The capability to assess surface condition prior to bonding is crucial to successful bonded structures. This work will determine what techniques can identify an acceptable bond for a durable product and which can be transitioned to manufacturing and field service. This will support the new transport applications of composite structural repair as well as current applications.

Starship Teardown and Aging of Composites
This is a vital part of the understanding of the durability of the present design concepts for composite structural components. The design philosophies used in this aircraft will certainly be the building blocks for the next generation of large transport all-composite fuselages. The knowledge of durability of past design practices discovered during this investigation will directly affect the FAA's ability to assure safe large scale structures.

Friction Stir Welded Joints
This technology is poised to be used on large transport and small business jet aircraft and an increasing number of small GA type aircraft. The current state of the art in aircraft design utilizing this technology is essentially a point design. A true understanding of the broader usage questions must be conducted to assure these emerging applications are safe. There is a high probability that it will be used on the next generation of GA and transport aircraft and redesign of current products. The global concept here is to understand the variables unique to an aircraft production environment and produce data that can be used for design of the joints.

Repair of Composite Structures
The ability to perform repairs on a composite commercial transport fuselage must be developed. This is important to the operator so he or she has the means to keep the airplanes safe. These repairs must be able to restore the structural capability so that integrity is not compromised. Optimum repairs have not been developed for fuselage materials and structural arrangements.

Crashworthiness of Composites-Material Dynamic Properties
The crashworthiness of a fully composite fuselage is not understood. Stiffness and structural arrangement differences between a traditional metallic and composite commercial transport will result in difference forces being transmitted to passengers during a crash. These differences must be understood by the FAA in order to ensure a safe aircraft.

Small Airplane Flight Load Monitoring
The operational loads research for Part 23 airplanes is to establish a statistical loads database that accounts for loads variability due to operational usage. This includes installing multi-channel data recorders on different types of airplanes (e.g., business jets, surveillance airplanes, firefighting airplanes, and agricultural airplanes), and collecting center of gravity accelerations, airspeed, altitude and other data as appropriate. The data will then be reduced and analyzed to determine maneuver and gust exceedance spectra as a function of usage.