How should you choose aircraft parts? Choosing the wrong ones will endanger your aircraft and may lead to an accident. You can avoid this by adhering to universal aircraft hardware quality standards. New aircraft parts do not need history, but if you choose a used one, you must be aware of its history.
Quality
When choosing aircraft hardware, there are many things to look for. Genuine aircraft hardware must have a certificate of conformance (COC) if it is critical or high-stress. Check for AN designation (AN 3 through AN 20) to ensure the bolt has a certified standard. Also, look for bolts with a C or H that denote corrosion resistance or a safety wire hole.
The Standard Aircraft Handbook and the Aviation Mechanic Handbook are excellent resources for learning about aircraft hardware. You can also consult legit and authorized hardware distributors or ask the aircraft kit manufacturer for recommendations regarding the type of hardware to use for your aircraft project. If you are unsure about the quality of a particular hardware item, request a copy of the manufacturer’s specifications, including the lot number of the part you are buying. Then, use the specifications to help you decide on whether to purchase that part or not.
Cost
When purchasing a new airplane, airlines often start with the list price and select the standard set of components for the aircraft. To ensure maximum efficiency, Boeing has reduced the number of options available in its 787 plane and the associated cost. For example, purchasing a hand-me-down part will cost up to $2 million, about half the price of a brand-new part. However, even this option is not available for every aircraft model.
A large percentage of the overall cost of military aircraft is related to aircraft maintenance and support (O&S) costs. The major contributors to these costs are the materials used for maintenance and personnel. Several critical areas for cutting aircraft-support expenses have been identified: eliminating premature failures in the field, developing more efficient inspection techniques, and reducing the cost of raw materials and procured hardware. The goal of cost efficiency is to increase efficiency and improve quality.
Materials
When choosing aircraft hardware, there are several factors to consider, including its size, weight, and strength. The fasteners must be able to transfer the weight from the engine, pylon, wing, and fuselage. To transfer the weight effectively, the diameter of the fastener must be measured to ensure a proper fit. Other factors, including weight and cost, are also taken into account. Fasteners are divided into structural and nonstructural parts.
The operating conditions of an aircraft’s components determine which material is best for the parts it includes. Aircraft must resist high temperatures, humidity, corrosion, and noise. Therefore, their materials should be lightweight and strong yet durable and corrosion-resistant. In the past, aircraft made of wood and fabrics were a common material for aircraft parts, but these materials quickly degraded and required expensive maintenance. Nowadays, the preferred materials for aircraft hardware are steel, aluminum, and titanium.
Placement
The Placement of Aircraft Hardware refers to placing hardware components in an aircraft. A specific specification number identifies hardware components. These parts are marked with letters, dashes, or both. The Placement of Aircraft Hardware is an essential part of the aircraft.
Inspection
There are many types of aircraft inspections. The most common is the annual or routine inspection, but some parts or systems require special inspections. For example, an altimeter system, which tells an aircraft’s altitude above sea level, must be inspected no less than 24 months before flights. A transponder is another component that must be inspected annually to ensure it works correctly and without error. Inspections may require disassembly, depending on flight conditions.
A standard method is to use a visual inspection to examine the condition of aircraft hardware. The resulting data is then used to determine if the components are structurally sound or need to be repaired. For example, the aircraft industry frequently uses tapered interference-fit fasteners, renowned for their fatigue strength. Engineers use a true geometry gauge coated with a thin layer of engineer’s blue to inspect aircraft parts. By examining this pattern, they can identify the bearing surface area and distribution. In addition, researchers are exploring whether the inspection process reflects hole geometry without human subjectivity.
