Aircraft wires

This 1949 DuPont promotional photo shows how a Teflon rod (on our right, in the model s left hand) resists a hot acid solution compared with a rod made from another plastic. In World War II, Teflon was used for insulation in aircraft wiring and for seals in the equipment used to enrich corrosive uranium hexafluoride. 

Fluoropolymers. Melt processable fluoropolymers such as Teflon FEP, Tefzel ETFE, poly(vinylidene fluoride) (Kynar), and ethylene-chlorotrifluoroethylene copolymer (Halar) are suitable for wire insulation in special applications because they combine good physical properties with low flammability. They are used for instrumentation cable in process-control rooms, as well as for computer and aircraft wiring and in military applications. The... 

B. Waddoups, C. Furse, and M. Schmidt, Analysis of reflectometry for detection of chafed aircraft wiring insulation, NASA, 09/2001. 

The ferroelectricity, combined with excellent mechanical properties and the ease of fabrication, have rendered PVF2 a versatile material for piezoelectric and pyroelectric applications (transducer, stems, ultrasonics, loudspeakers, microphones, finger-press switches, ultrared detectors). Furthermore, PVF2 can be found in semiconductor applications and in the electrical-electronic market (plenum cables, aircraft wiring, computer... 

Military and aerospace applications often require the highest level of reliability for systems where failure can have catastrophic consequences. Fluoroplastics fill critical needs for insulation in terrestrial, aviation, and space applications. Many of these applications are defined by Military Specifications (MIL SPEC) with two of the most important being MIL-C-17 for critical coaxial cable applications and MIL-W-22759 for fluoropolymer-insulated single conductor electrical wires primarily used as aircraft wire. 

The resistance of fluoropolymers to property changes over time is also important for aircraft wiring insulation. PVC and many other common polymers used for insulation must be compounded with plasticizers, fire retardants, and other materials to achieve required levels of performance. Some additives may migrate out of the insulation or undergo changes that will reduce performance to unacceptable levels. This deterioration can occur more rapidly at the high temperatures at which some aircraft wiring operates. 

After considering the possibility of the suppliers failing to deliver products on time, the aircraft wiring company has determined that there is a 97% chance that the overseas supplier will deliver on time and a 3% chance that they will not. There is a 99% chance that the local supplier will deliver on time and a 1% chance that they will not. With the information provided thus far, payoffs for each branch of the decision tree are calculated as follows ... 

Hard facing of various components in the aircraft gas-turbine engine and in industrial apphcations for textile machinery parts, oil and gas machinery parts, paper-shtting knives, etc, is estimated at 1 x 10 in 1995 with an estimated growth rate of 5% annually. The mix is approximately 45% aerospace apphcations, 55% industrial apphcations. Additionally, repair coatings for gas-turbine blades and vanes is estimated at 500 x 10 . These coatings are primarily deposited by plasma spray, arc-wire, HVOF, and detonation gun techniques. 

There are two types of input power buses. DC power buses are single-wire power connections such as found in automobiles and aircraft. The ground connection forms the other leg of the power system. The other form of input connection is the ac, or two or three-wire feed systems as found in ac power systems. The design of the EMI filter for dc systems is covered in Section 3.12 and takes the form of a simple L-C filter. All the noise is common-mode between the single power wire and the ground return. The dc filter is much more complicated, because of the parasitic behavior of the components involved. 

This copolymer has proved particularly suitable for wire and cable insulation, with many grades being rated at 155°C for 20 000 h continuous exposure. It is extensively used in electrical systems for aircraft, underground railways, computers, telecommunications installations and heating circuits. Because of its toughness combined with its heat and chemical resistance it also finds use for lining pumps and valves and other equipment for the chemical industry and for laboratory ware. 

These materials are developed from the polyetherimides introduced by General Electric (see also Section 18.14.2). At the time of writing one grade, Ultem Siltem STM 1500, is being offered. It is of particular interest as a material for wire and cable insulation, as it not only has excellent flame resistance coupled with low smoke generation but also avoids possible toxic and corrosion hazards of halogenated polymers. This can be of importance where there are possible escape problems in the event of a fire, such as in tunnels, aircraft and marine (particularly submarine) vessels. 

PVDF IS used as a coating for metallic architectural substrates such as roofing, panel siding, and windows, and for wire insulation in the electronics and aircraft industries It is also used to mold pipes... 

Applications Ion implantation is widely employed to improve the life of tools. Thus press tools, dies and gear cutters can be treated to increase their durability by three times or more. Nitrogen-implanted tungsten carbide drawing dies for copper and iron wire can be improved up to fivefold. By implanting chromium, aluminium or silicon a considerable increase in the corrosion resistance of steel can be obtained. Implantation of chromium into aircraft bearing alloys has improved their durability in marine environments . 

Nard 5210 (SS.11 and AS.11). A Fr line-of-sight wire-guided battlefield missile that can be fired from aircraft, vehicles and ships. The SS.ll is a surface-to-surface version, and the AS. 11 is a similar air-to-surface version... 

The primary and secondary aluminum industry produces ingots of pure (greater than 99%) aluminum that serve as feedstock for other materials and processes. Within the U.S., the leading end-users of aluminum come from three industries containers and packaging, transportation, and building and construction. Examples of materials produced with aluminum are sheet metal aluminum plate and foil rod, bar, and wire beverage cans automobiles aircraft components and window/door frames. 

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