Gear bearings are, as their name implies, a combination of both gear and bearing functions in one component. Like gears, they feature teeth that intermesh with one another, and like bearings they do so to transfer radial and axial loads to bear weight and friction. Gear bearings improve drives in electrical, internal combustion, and turbine motors. The gear bearing design incorporates rifle-true anti-backlash, improved thrust bearing performance, and phase-tuning techniques for superior low-speed reduction. Because they combine both gear and bearing functions, gear bearings can reduce weight, number of parts, size and cost, and increase load capacity.
 
Gear bearings come with numerous benefits and advantages over conventional bearings. Because they eliminate backlash, they are smoother in operation and control. The teeth design in gear bearings gives them superior thrust bearing performance. Gear bearings can also run quieter and with less vibration and suffer fewer fatigue failures. They are also fairly cheap and simple to design and manufacture, while also being more structurally rigid and possess higher load capacity than fixed planetary designs. They can also enable all-electric actuator systems and eliminate hydraulics in many applications.
 
Gear bearings are used in countless applications. They can be found in almost all forms of transportation including automotive, aviation, marine, and rail. They are also vital for transmissions, electric windows, windshield wipers, steering mechanisms, alternators and generators, engines and propellers, and bearing landing gear. They can also be found in power tools like gardening equipment, chain saws, power drills, and screw drivers. In industrial machinery, they are used in power presses, lathes, and construction equipment, and in farming equipment like tractors, harvesters, and hay rollers.

A needle roller bearing is a type of bearing that utilizes small cylindrical rollers that reduce the friction of a rotating surface. In comparison to ball bearings, needle roller bearings have a large surface area that is in contact with the functioning part. These are useful in manufacturing because of their ability to handle relatively high loads in a compact design. They are the smallest and lightest of the roller bearing family which gives them the advantage in limited space situations.
 
These bearings come in several different configurations including drawn cup, precision race, caged roller, and thrust roller bearings. The type that appears most often is the caged roller needle bearing. The caged roller bearings function is to support radial loads and rotational speeds.  Developments to these bearings contour have been introduced to reduce roller-end stress from misalignment, or deflection, of one of their base balancing components (known as raceways). These developments enable a more uniform distribution of stress, optimizing the bearings performance. Typical applications for caged needle roller bearings are automotive transmission systems, two and four stroke engines, gearboxes, air compressors, and planetary gear sets.
 
Although these bearings often serve purposes elsewhere, they are typically designed to meet the specific needs of the aircraft industry in airframe manufacturing. Their design involves heavy outer rings to support high static, oscillating loads. These bearing rings and rollers are constructed of high-carbon chrome steel and are made with a protective finish. Some are intended to work as track rollers while others have applications in mounting housing. For heavier rolling loads, needle roller bearings are wider and have two rows of rollers. In situations with lighter rolling loads, only one row of rollers is needed.
 
Needle roller bearings are capable of higher load capacities than single-row ball bearings or roller bearings. They have the ability to handle larger, more rigid applications. Their excellent roller characteristics within a small cross section also add to their appeal. They are generally lower cost in comparison with other bearings as well. All of these attributes contribute to why needle roller bearings are a vital component in aircraft manufacturing.

Fiber optic cables get all the praise when it comes to new data transmission technology, but their efficiency greatly relies on a few small power connector components— cable connectors. The size and versatility of a fiber connector allows fiber optic cabling to transmit data across distributed avionics and eliminate the need for additional signal support equipment.
 
Fiber optic connectors hold individual fibers in place. They incorporate an associated adapter for alignment and mating of fiber ends which forms a unified connection point. Another way to think of this device is as a plug with a protruding ferrule. A ferrule protects the mating ends of a fiber from degradation, as splitting or cracking will damage the fiber’s ability to reflect light effectively.
 
While airlines formerly had to rely on an avionics bay to route data through the aircraft, the compact size of the fiber optic optical connector allows distributed avionics to put processing power closer to its point of use. Most aircraft formerly utilized copper cables, which require additional equipment for signal support, adding to overall weight. As a result, fiber optic cables offer 25% in space savings and 50% overall weight reduction. Connectors with composite shells are 40% lighter than metal connectors.
 
Along with knowing the benefits of connectors, you’ll want to know about the most common connectors that you might come across in aviation. Common 2.5 mm connectors, small form factor connectors, and multi-fiber push on connectors are the most prevalent fiber connectors used within the aviation industry. A general rule for this category of connectors is the following: common 2.5 mm connectors are the most versatile, small form factor(SFF) connectors are intended for high density purposes, and multi-fiber push ons (MPO) support high-data environments. 
 
There are three types of 2.5 mm common connectors, square connectors (SC), firewire connectors (FC), and stainless-steel connectors (ST).  As their name suggests, common 2.5 mm connectors have a 2.5 mm ferrule size and therefore can be used interchangeably, or mixed and matched with the addition of a hybrid adapter. These connectors were commonly used in the 1980’s and 1990’s, but the SC connector is still commonly seen in application with fiber optics.
 
SFF connectors have a latch design that allows for strong connections with reduced signal loss. In addition, it has a 1.25 mm ferrule giving it a compact and reliable design. The low loss connector (LC), a variety of SFF, is one of the most successful connectors in the industry.
 
To round out our connectors, the most commonly used power connector component in aviation is the MPO. With the rapid advancement of avionic technology, these connectors are necessary to provide high speed data transfer end-to-end. This connector can contain a multitude of fibers and can incorporate multimode fibers as well. MPO connectors are specified as “male” on one end and “female” on the other to ensure that all fibers are properly aligned.

DC Power Connectors are electrical connectors used for supplying direct current (DC) power. They have standard types that aren’t interchangeable. The correct dimensions and arrangement should be chosen to prevent interconnection of incompatible sources and loads. They are used in a variety of applications, including small portable electronics and automotive accessories. There are three common types of barrel connectors: jacks, plugs, and receptacles.
 
Barrel Box connectors, or low voltage DC power connectors, have current and voltage ratings, specified by the manufacturer. The jack and the plug feature one exposed conductor and a recessed conductor. Jacks usually receive power and are mounted inside the appliance. A plug is usually located on the electrical cord and supplies power from a power supply. A receptacle is mounted on a power cord as well but receives power from a mating plug. Most engineers accept the center pin configuration as the defining factor for the gender of barrel power connectors. “Male” connectors have a center pin, and the mating receptacles are deemed “female”.
 
A common way of categorizing barrel connectors is through the diameter of the inner pin and outer sleeve. The diameter of the inner sleeve should be slightly larger than that of the mating pin. Typical mating connections are cantilevered flat springs. Jack insertion Connectors depth dimensions are often less than the plug barrel lengths for the following two reasons. First, the plug barrel may not be required to be completely enclosed by the receiving jack. Second, the depth of the chassis wall must be considered. Additional depth should be accounted for in the plug barrel length when the connectors are mated. 
 
Connector Plugs and jacks often have two conductors, one for power and one for ground. Usually, the center pin is power, and the outer sleeve is ground, but it’s possible for it to be the opposite. Some jacks have a third connector that forms a switch with the outer sleeve conductor; this is used to detect the insertion of a plug or to select between power sources.

Aircraft inspection plates, doors, and other removable panels are secured with turnlock fasteners because they allow quick and easy removal of panels for inspection and servicing. These fasteners require positive sustained torque to unfasten and tend to correct themselves after minor disturbances. The most common manufactured turnlock fasteners are Dzus, Camloc, and Airloc. Some of the common names used to refer to turnlock fasteners are quick opening, quick action, and stressed panel fasteners.

Dzus turnlock fasteners have a stud, grommet, and receptacle. The stud is made from steel and are cadmium plated. There are three head styles: wing, flush, and oval. Turning the stud clockwise locks the fastener and turning it counterclockwise unlocks it. This is done using a specialized tool. The force that locks the stud in place is created by the spring.

Some of the most commonly used Camloc fasteners are the 2600, 2700, 40S51, 4002, and the stressed panel fasteners. Camloc fasteners are used on aircraft cowlings and fairings. The fastener has a stud assembly, a grommet, and a receptacle. Receptacles are sorted into two categories: rigid type and floating type. The receptacle is fastened to the aircrafts structure and the stud and grommet are installed in the removable portion while the stud and grommet are installed in a plain, dimpled, countersunk, or counterbored hole.

Anchor Panel fasteners have a stud, a cross pin, and a stud receptacle. There are flush, oval, and wing studs. It is important to know the thickness of the material being secured, as it has to be determined in order to choose a stud of the correct length. The cross pin is made from chrome-vanadium steel that has been heat treated. They provide the greatest strength, wear, and holding power. Once a cross pin is removed from the stud, a new one must replace it.