The aerospace industry consists of manufacturers of aircraft, aircraft engines, aircraft parts, guided missiles and space vehicles, and guided missile and space vehicle propulsion units and parts.

Aerospace operations are often classified as either military or commercial and as either original equipment manufacturers (OEM) or rework. Most aerospace facilities specialize in either military or commercial and either rework or OEM. OEM facilities might do both military and commercial work, and likewise for rework facilities.

Aerospace manufacturing utilizes a broad supply chain, and consumes a vast amount and array of parts and materials and resources. Aside from final assembly of the aircraft, aerospace manufacturing has common capabilities to many other sectors, such as machining, metal surface prep and finishing (painting, plating, coating, etc.), electronics and printed circuit board fabrication, composites fabrication and layup. Some of these processes may occur at the aerospace manufacturing facility itself, or may be outsourced to suppliers.

NAICS codes for aerospace and defense industries include the following (however the supply chain is not limited to this list):

• NAICS 336411 Aircraft Manufacturing
• NAICS 336412 Aircraft Engine and Engine Parts Manufacturing
• NAICS 336413 Other Aircraft Parts and Auxiliary Equipment Manufacturing
• NAICS 336414 Guided Missile and Space Vehicle Manufacturing
• NAICS 336415 Guided Missile and Space Vehicle Propulsion Unit and Propulsion Unit Parts Manufacturing
• NAICS 336419 Other Guided Missile and Space Vehicle Parts and Auxiliary Equipment Manufacturing

Many of the parts used by aerospace manufacturers are made by other industry sectors such as the plastics and rubber industry, the fabricated metal industry, the metal casting industry, the glass industry, the textile industry, and the electronic components industry. Manufacturing and assembling of complete units in the aerospace industry typically involves prime contractors and several tiers of subcontractors, as follows:

• Prime Contractors - Design (develop) and assemble or manufacture complete units.
• First Tier Subcontractors - Do major assembly and/or manufacture of sections of air/space craft without designing or assembling complete units.
• Second Tier Subcontractors - Make various subassemblies and sections.
• Third Tier Subcontractors - Produce machined components and sub-assemblies.
• Fourth Tier Subcontractors - Specialize in the production of particular components and in specific processes.

Please continue on ot the next sections of this document which provide information on processes commonly used in aerospace manufacturing and the supply chain, operations, resource inputs and waste outputs of this industry, opportunities to reduce waste and pollution in this industry, and reasons why aerospace manufacturers should implement pollution prevention.