R307-355-4. Definitions

  The following additional definitions apply to R307-355:

  "Ablative coating" means a coating, applied to both new and rework aerospace components, which chars and becomes intumescent when exposed to open flame, such as would occur during the failure of an engine casing. The purpose of the coating is to act as an isolative barrier and protect adjacent metal parts from an open flame.

  "Adhesion promoter" means a very thin coating applied to a substrate to promote wetting and form a chemical bond with the subsequently applied material.

  "Adhesive bonding primer" means a primer applied in a thin film to aerospace components for the purpose of corrosion inhibition and increased adhesive bond strength by attachment. There are two categories of adhesive bonding primers: primers with a design cure at 250 degrees Fahrenheit or below and primers with a design cure above 250 degrees Fahrenheit.

  "Aerospace manufacture and rework facility" means any installation that produces, reworks, or repairs in any amount any commercial, civil, or military aerospace vehicle or component.

  "Aerospace vehicle or component" means any fabricated part, processed part, assembly of parts, or completed unit, with the exception of electronic components, of any aircraft including but not limited to airplanes, helicopters, missiles, rockets, and space vehicles. This definition includes integral equipment such as models, mock-ups, prototypes, molds, jigs, and tooling. It also includes auxiliary equipment associated with test, transport and storage that through contamination can compromise aerospace vehicle performance.

  "Antique aerospace vehicle or component" means an aircraft or component thereof that was built at least 30 years ago and would not routinely be in commercial or military service in the capacity for which it was designed.

  "Bearing coating" means a coating applied to an antifriction bearing, a bearing housing, or the area adjacent to such a bearing in order to facilitate bearing function or to protect base material from excessive wear. A material shall not be classified as a bearing coating if it can also be classified as a dry lubricative material or a solid film lubricant.

  "Caulking and smoothing compounds" means semi-solid materials which are applied by hand application methods and are used to aerodynamically smooth exterior vehicle surfaces or fill cavities such as bolt hole accesses. A material shall not be classified as a caulking and smoothing compound if it can also be classified as a sealant.

  "Chemical agent-resistant coating" means an exterior topcoat designed to withstand exposure to chemical warfare agents or the decontaminants used on these agents.

  "Chemical milling maskants" means a coating that is applied directly to aluminum components to protect surface areas when chemical milling the component with a Type I or Type II etchant. Type I chemical milling maskants are used with a Type I etchant and Type II chemical milling maskants are used with a Type II etchant.

  "Clear coating" means a transparent coating usually applied over a colored opaque coating, metallic substrate, or placard to give improved gloss and protection to the color coat. In some cases, a clear coat refers to any transparent coating without regard to substrate.

  "Commercial exterior aerodynamic structure primer" means a primer used on aerodynamic components and structures that protrude from the fuselage, such as wings and attached components, control surfaces, horizontal stabilizers, vertical fins, wing-to-body fairings, antennae, and landing gear and doors, for the purpose of extended corrosion protection and enhanced adhesion.

  "Compatible substrate primer" means either compatible epoxy primer or adhesive primer. Compatible epoxy primer is primer that is compatible with the filled elastomeric coating and is epoxy based. The compatible substrate primer is an epoxypolyamide primer used to promote adhesion of elastomeric coatings such as impact-resistant coatings. Adhesive primer is a coating that:

  (1) inhibits corrosion and serves as a primer applied to bare metal surfaces or prior to adhesive application, or

  (2) is applied to surfaces that can be expected to contain fuel. Fuel tank coatings are excluded from this category.

  "Corrosion prevention" means a coating that provides corrosion protection by displacing water and penetrating mating surfaces, forming a protective barrier between the metal surface and moisture. Coatings containing oils or waxes are excluded from this category.

  "Cryoprotective coating" means a coating that insulates cryogenic or subcooled surfaces to limit propellant boil-off, maintain structural integrity of metallic structures during ascent or re-entry, and prevent ice formation.

  "Electric or radiation-effect coating" means a coating or coating system engineered to interact, through absorption or reflection, with specific regions of the electromagnetic energy spectrum, such as the ultraviolet, visible, infrared, or microwave regions. Uses include, but are not limited to, lightning strike protection, electromagnetic pulse (EMP) protection, and radar avoidance. Coatings that have been designated as "classified" by the Department of Defense are exempt.

  "Electrostatic discharge and electromagnetic interference (EMI) coating" means a coating applied to space vehicles, missiles, aircraft radomes, and helicopter blades to disperse static energy or reduce electromagnetic interference.

  "Elevated-temperature Skydrol-resistant primer" means a primer that must withstand immersion in phosphate-ester (PE) hydraulic fluid (Skydrol 500b A-9 or equivalent) at the elevated temperature of 150 degrees Fahrenheit for 1,000 hours.

  "Epoxy polyamide topcoat" means a coating used where harder films are required or in some areas where engraving is accomplished in camouflage colors.

  "Fire-resistant (interior) coating" means for civilian aircraft, fire-resistant interior coatings are used on passenger cabin interior parts that are subject to the FAA fireworthiness requirements. For military aircraft, fire-resistant interior coatings are used on parts that are subject to the flammability requirements of MIL-STD-1630A and MIL-A-87721. For space applications, these coatings are used on parts that are subject to the flammability requirements of SE-R-0006 and SSP 30233.

  "Flexible primer" means a primer that meets flexibility requirements such as those needed for adhesive bond primed fastener heads or on surfaces expected to contain fuel. The flexible coating is required because it provides a compatible, flexible substrate over bonded sheet rubber and rubber-type coatings as well as a flexible bridge between the fasteners, skin, and skin-to-skin joints on outer aircraft skins. This flexible bridge allows more topcoat flexibility around fasteners and decreases the chance of the topcoat cracking around the fasteners. The result is better corrosion resistance.

  "Flight test coating" means a coating applied to aircraft other than missiles or single-use aircraft prior to flight testing to protect the aircraft from corrosion and to provide required marking during flight test evaluation.

  "Fuel tank coating" means a coating applied to fuel tank components for the purpose of corrosion and/or bacterial growth inhibition and to assure sealant adhesion in extreme environmental conditions.

  "General aviation" means that segment of civil aviation that encompasses all facets of aviation except air carriers, commuters, and military. General aviation includes charter and corporate-executive transportation, instruction, rental, aerial application, aerial observation, business, pleasure, and other special uses.

  "High-temperature coating" means a coating designed to withstand temperatures of more than 350 degrees Fahrenheit.

  "Insulation covering" means material that is applied to foam insulation to protect the insulation from mechanical or environmental damage.

  "Intermediate release coating" means a thin coating applied beneath topcoats to assist in removing the topcoat in depainting operations and generally to allow the use of less hazardous depainting methods.

  "Lacquer" means a clear or pigmented coating formulated with anitrocellulose or synthetic resin to dry by evaporation without a chemical reaction. Lacquers are resoluble in their original solvent.

  "Low vapor pressure hydrocarbon-based cleaning solvent" means a cleaning solvent that is composed of a mixture of photochemically reactive hydrocarbons and oxygenated hydrocarbons and has a maximum vapor pressure of 7 mm Hg at 68 degrees Fahrenheit. These cleaners must not contain hazardous air pollutants.

  "Maskants" means a coating that is applied directly to aluminum components to protect surface areas when chemical milling the component with a Type I or Type II etchant. Type I chemical milling maskants are used with a Type I etchant and Type II chemical milling maskants are used with a Type II etchant.

  "Metalized epoxy coating" means a coating that contains relatively large quantities of metallic pigmentation for appearance and/or added protection.

  "Mold release" means a coating applied to a mold surface to prevent the molded piece from sticking to the mold as it is removed.

  "Optical anti-reflection coating" means a coating with a low reflectance in the infrared and visible wavelength ranges that is used for antireflection on or near optical and laser hardware.

  "Part marking coating" means coatings or inks used to make identifying markings on materials, components, and/or assemblies. These markings may be either permanent or temporary.

  "Pretreatment coating" means an organic coating that contains at least 0.5 percent acids by weight and is applied directly to A-12 metal or composite surfaces to provide surface etching, corrosion resistance, adhesion, and ease of stripping.

  "Primer" means the first layer and any subsequent layers of identically formulated coating applied to the surface of an aerospace vehicle or component. Primers are typically used for corrosion prevention, protection from the environment, functional fluid resistance, and adhesion of subsequent coatings. Primers that are defined as specialty coatings are not included under this definition.

  "Rain erosion resistant coating" means a coating applied primarily to radomes, canopies, and leading edges of aircraft to provide protection from erosion due to rain, dust, and other airborne particles.

  "Rework facility" means any installation that repairs any aerospace vehicle or component.

  "Rocket motor nozzle coating" means a catalyzed epoxy coating system used in elevated temperature applications on rocket motor nozzles.

  "Scale inhibitor" means a coating that is applied to the surface of a part prior to thermal processing to inhibit the formation of scale.

  "Screen print ink" means an ink used in screen printing processes during fabrication of decorative laminates and decals.

  "Sealant" means a material used to prevent the intrusion of water, fuel, air, or other liquids or solids from certain areas of aerospace vehicles or components. There are two categories of sealants: extrudable/rollable/brushable sealants and sprayable sealants.

  "Silicone insulation material" means an insulating material applied to exterior metal surfaces for protection from high temperatures caused by atmospheric friction or engine exhaust. These materials differ from ablative coatings in that they are not "sacrificial."

  "Solid film lubricant" means a dry lubricant coating used to reduce friction between faying metal surfaces. The coating consists of an organic binder system containing one or more of the following substances: molybdenum disulfide, graphite, polytetrafluoroethylene (Teflon PTFE), other types of Teflon, lauric acid, cetyl alcohol, or waxes.

  "Space vehicle" means a man-made device, either manned or unmanned, designed for operation beyond earth's atmosphere. This definition includes integral equipment such as models, mock-ups, prototypes, mold, jigs, tooling, hardware jackets and test coupons. Also included, auxiliary equipment associated with test, transport and storage that through contamination can compromise the space vehicle performance.

  "Specialized function coating" means a coating that fulfills extremely specific engineering requirements that are limited in application and are characterized by low volume usage. This category excludes coatings covered in other Specialty Coating categories.

  "Specialty coating" means a coating that, even though it meets the definition of a primer, topcoat, or self-priming topcoat, has additional performance criteria beyond those of primers, topcoats, and self-priming topcoats for specific applications.

  (1) These performance criteria may include, but are not limited to, temperature or fire resistance, substrate compatibility, antireflection, temporary protection or marking, sealing, adhesively joining substrates, or enhanced corrosion protection.

  "Temporary protective coating" means a coating applied to provide scratch or corrosion protection during manufacturing, storage, or transportation. Two types include peelable protective coatings and alkaline removable coatings. These materials are not intended to protect against strong acid or alkaline solutions. Coatings that provide this type of protection from chemical processing are not included in this category.

  "Thermal control coating" means a coating formulated with specific thermal conductive or radiative properties to permit temperature control of the substrate.

  "Topcoat" means a coating that is applied over a primer or component for appearance, identification, camouflage, or protection. Topcoats that are defined as specialty coatings are not included under this definition.

  "Wet fastener installation coating" means a primer or sealer applied by dipping, brushing, or daubing to fasteners that are installed before the coating is cured.

  "Wing coating" means a corrosion-resistant topcoat that is resilient enough to withstand the flexing of the wings.