Aircraft Construction

Aircraft Design, Certification, and process, each part is inspected to ensure that it has been built Airworthiness exactly according to the approved design. This inspection is called a conformity inspection. The FAA certifies three types of aviation products: aircraft, aircraft engines, and propellers. Each of these products When the aircraft is complete, with the airframe, engine, and has been designed to a set of airworthiness standards. propeller, it is inspected and the FAA issues an airworthiness These standards are parts of Title 14 of the Code of certificate for the aircraft. Having an airworthiness Federal Regulations (14 CFR), published by the FAA. The certificate means the complete aircraft meets the design and airworthiness standards were developed to help ensure that manufacturing standards, and is in a condition for safe flight. aviation products are designed with no unsafe features. This airworthiness certificate must be carried in the aircraft Different airworthiness standards apply to the different during all flight operations. The airworthiness certificate categories of aviation products as follows: remains valid as long as the required maintenance and • Normal, Utility, Acrobatic, and Commuter Category inspections are kept up to date for the aircraft. Airplanes- 14 CFR part 23 • Transport Category Airplanes—14 CFR part 25 Airworthiness certificates are classified as either “Standard” or “Special.” Standard airworthiness certificates are white, • Normal Category—14 CFR part 27 and are issued for normal, utility, acrobatic, commuter, or • Transport Category Rotorcraft—14 CFR part 29 transport category aircraft. They are also issued for manned • Manned Free Balloons—14 CFR part 31 free balloons and aircraft designated as “Special Class.” • Aircraft Engines—14 CFR part 33 Special airworthiness certificates are pink, and are issued • Propellers—14 CFR part 35 for primary, restricted, and limited category aircraft, and light sport aircraft. They are also issued as provisional Some aircraft are considered “special classes” of aircraft and airworthiness certificates, special flight permits (ferry do not have their own airworthiness standards, such as gliders permits), and for experimental aircraft. and powered lift. The airworthiness standards used for these aircraft are a combination of requirements in 14 CFR parts More information on airworthiness certificates can be found 23, 25, 27, and 29 that the FAA and the designer have agreed in Chapter 9, in 14 CFR parts 175-225, and also on the FAA are appropriate for the proposed aircraft. website at www.faa.gov. The FAA issues a Type Certificate (TC) for the product Lift and Basic Aerodynamics when they are satisfied it complies with the applicable In order to understand the operation of the major components airworthiness standards. When the TC is issued, a Type and subcomponents of an aircraft, it is important to Certificate Data Sheet (TCDS) is generated that specifies understand basic aerodynamic concepts. This chapter briefly the important design and operational characteristics of the introduces aerodynamics; a more detailed explanation can be aircraft, aircraft engine, or propeller. The TCDS defines the found in Chapter 5, Aerodynamics of Flight. product and are available to the public from the FAA website at www.faa.gov. Four forces act upon an aircraft in relation to straight-and- level, unaccelerated flight. These forces are thrust, lift, A Note About Light Sport Aircraft weight, and drag. [Figure 3-1] Light sport aircraft are not designed according to FAA airworthiness standards. Instead, they are designed to a Thrust is the forward force produced by the powerplant/ consensus of standards agreed upon in the aviation industry. propeller. It opposes or overcomes the force of drag. As a The FAA has agreed the consensus of standards is acceptable general rule, it is said to act parallel to the longitudinal axis. as the design criteria for these aircraft. Light sport aircraft do This is not always the case as explained later. not necessarily have individually type certificated engines and propellers. Instead, a TC is issued to the aircraft as a Drag is a rearward, retarding force and is caused by disruption whole. It includes the airframe, engine, and propeller. of airflow by the wing, fuselage, and other protruding objects. Drag opposes thrust and acts rearward parallel to the relative Aircraft, aircraft engines, and propellers can be manufactured wind. one at a time from the design drawings, or through an FAA approved manufacturing process, depending on the size and capabilities of the manufacturer. During the manufacturing 3-2