Introduction
The small airplane certification process requires an aircraft to meet a variety of criteria, most of which are structural. To ensure the safe operation of aircraft for a long time, engineers need to undergo certification of all aircraft equipment. It is necessary for “upgrading airplanes with better systems (e.g., alternators), newer avionics (e.g., NextGen, navigation, information, or redundancy), and safety gear (e.g., ballistic parachutes and inflatable restraints)” (U.S. Department of Transportation Federal Aviation Administration, 2009, p. 7). The airworthiness of aircraft requires a careful and extremely detailed approach.
Airworthiness: FAR 25
The concept of airworthiness needs to be brought up as one of the foundational notions associated with quality in aviation and the provision of safety and security for U.S. citizens. According to the definition provided by FAR, the phenomenon of airworthiness implies alignment with several rigid standards and incorporates a range of stringent standards that aircraft must meet to continue providing services (“Part 25—Airworthiness standards: Transport category airplanes,” n.d.). Specifically, the notions of applicability, the issue of control, and the factors associated with proper performance and maintenance of aircraft should be addressed as some of the core quality standards that the FAR has set to ensure the safety and security of the parties involved, including the staff and the passengers.
The maximum coefficient of braking friction of the landing gear to the ground for the runway must be corrected for the effectiveness of the anti-skid system on the runway. A higher coefficient of braking friction for a wet runway can be used for corrugated runway surfaces or runways covered with a special porous material (U.S. Department of Transportation Federal Aviation Administration, 2017). The coefficient of wet runway braking friction for corrugated and porous runways is determined by one of the following methods. 70% dry runway braking friction factor used to determine dry runway rejected takeoff distance. Another method could be the wet runway braking factor, except that the effectiveness of the anti-skid system (if determined) is that of a grooved or porous wet runway.
Reliable means must be provided to hold the landing gear in the extended position in flight and on the ground, and in the retracted position in flight. released (or retracted) position. If switches are used, they must be located and connected to the mechanical systems of the chassis in such a way as to prevent the erroneous indication “Locked out and locked”(14 CFR Chapter I, n.d). If the landing gear is not fully extended, or “Retracted and locked”, if the landing gear is not fully retracted, then each position must be assigned an indicator. These switches may be located where they are actuated directly by a locking lock or other chassis device.
Advisory Circular Compliance
The compliance process is governed by special procedures that must be followed. Advisory Circular (AC) of 2017 recommends using the relevant AC as a means of compliance, as well as “the prescriptive provisions within previous amendments of part 23, where applicable” (U.S. Department of Transportation Federal Aviation Administration, 2017). Special attention should be paid to the rationale for choosing means of compliance when applying to the Project Aircraft Certification Office (PACO) (U.S. Department of Transportation Federal Aviation Administration, 2017 U.S. Department of Transportation Federal Aviation Administration, 2014a). It is required to consider conditions stated in 14 CFR, which provide standards on the certification criteria (14 CFR Chapter I, n.d). Thus, the second step for successful compliance is to find the necessary AC as a means of compliance, as well as other relevant regulations.
To complete the certification process, several structural criteria must be considered and verified. The listed criteria and compliance guidance are further proposed in AC on system safety analysis and assessment for part 23 aircraft, as well as in AC on proof of structure (U.S. Department of Transportation Federal Aviation Administration, 2011; U.S. Department of Transportation Federal Aviation Administration, 2014b). In these documents, you can find regulations on specific structural elements for part 23 aircraft.
Landing Gear
The landing gear is an indispensable structure in aircraft and needs to be carefully checked and complied with the regulations. Chassis and their attachments are a type of mechanism that cannot be defined by a damage-resistant design. In this regard, the regulation of compliance with the rules regarding the chassis must be strictly observed. Compliance with the regulation must be ensured in the following way: the landing gear is brought in a position that meets the tests or performance requirements of the aircraft, in modes that use Vsr speed (Part 25—Airworthiness standards: Transport category airplanes, n.d.). Additionally, according to Show Compliance guidance, it must be proven that the landing gear retracts and extends accordingly.
Conclusion
Moreover, a check was made regarding the landing of the aircraft on the surface with idle or broken landing gear. However, to avoid damage, the speed is the ground reference speed at which the aircraft takes off from the ground. Compliance with the regulation involves determining the maximum coefficient of braking friction of the wheel tire with the ground. It is set by calculating the tire pressure, the maximum ground braking ratio, and the aircraft’s true ground speed. Thus, the tires are determined to be suitable and the aircraft is qualified accordingly.
References
14 CFR Chapter I – Federal Aviation Administration, Department of Transportation. (n.d). Legal Information Institute.
Department of Defense. (1998). JSSG-2006. U. S. Department of Defense.
FAA. (2011). AC 39-9 – Airworthiness directives management process. Federal Aviation Administration.
Federal Aviation Administration. (2009). Part 23 – Small airplane certification process study: Recommendations for general aviation for the next 20 years. Federal Aviation Administration.
Part 25—Airworthiness standards: Transport category airplanes. (n.d.). Aviation Regulations.
U.S. Department of transportation Federal Aviation Administration. (2016). Airworthiness approval positioning and navigation systems.Federal Aviation Administration.
U.S. Department of transportation Federal Aviation Administration. (2017). FAA accepted means of comlience process for 14 CFR Part 23. Federal Aviation Administration.
U.S. Department of transportation Federal Aviation Administration. (2014a). Issue paper process. Federal Aviation Administration.
U.S. Department of transportation Federal Aviation Administration. (2014b). Proof of structure.Federal Aviation Administration.
U.S. Department of transportation Federal Aviation Administration. (2011). Systems safety analysis and assessment for part 23 airplanes. Federal Aviation Administration.