M6 Part 5 (Final)

Inner and outer bearing races are found in ball and roller bearings. Bearing races are the surfaces on which the balls or rollers of the bearing rotate. The inner race is the ring that is mounted on the rotating shaft, while the outer race is the ring that is mounted in the bearing housing. Both races are essential components of ball and roller bearings as they provide support and guidance for the rolling elements, allowing for smooth and efficient rotation. Plain bearings do not have separate inner and outer races, making ball and roller bearings the correct answer.

For an aircraft with a hydraulic system that operates above 3000psi, stainless steel tubing is the most likely choice for the fluid line. This is because stainless steel has high strength and corrosion resistance, making it suitable for handling high pressure and ensuring the integrity of the hydraulic system. Pure aluminum tubing may not have the necessary strength to withstand the high pressure, while aluminum alloy tubing may not provide sufficient corrosion resistance. Therefore, stainless steel tubing is the preferred option in this scenario.

A quick-disconnect coupling is a device used to join or disconnect fluid or gas lines quickly and easily. It typically consists of various components, such as a flared tube assembly, a flareless tube assembly, and two check valves. The flared tube assembly is designed to securely connect the tubing to the coupling, while the flareless tube assembly provides a tight seal without the need for flaring the tubing. The two check valves allow for the flow of fluid or gas in one direction while preventing backflow or leakage in the opposite direction.

Electrical cables that are exposed to the highest temperature on an aircraft are found in the engine. This is because the engine generates a significant amount of heat during operation, and the electrical cables in this area need to be able to withstand and function properly under high temperatures. The wings and fuselage of the aircraft are not exposed to the same level of heat as the engine, making it less likely for the cables in these areas to experience extreme temperatures.

The fuselage area below the galley and toilet is most prone to corrosion due to the presence of moisture and chemicals. This area is exposed to spills and leaks from the galley and toilet, which can lead to corrosion of the metal structure. Additionally, the constant exposure to moisture and humidity in this area can accelerate the corrosion process. Regular inspections and maintenance are necessary to prevent and address any corrosion issues in this specific area of the aircraft.

Turnbuckles are commonly used to tension cables. They consist of a metal body with right-hand and left-hand threaded ends, allowing for easy adjustment of the tension in the cable. By rotating the body, the distance between the ends can be increased or decreased, effectively tightening or loosening the cable. This makes turnbuckles a versatile and convenient tool for tensioning cables in various applications, such as in construction, marine, and suspension systems. Bolts and nuts can also be used to tension cables, but turnbuckles offer a more adjustable and precise method. Locking wires, on the other hand, are typically used for safety purposes to prevent bolts and nuts from loosening due to vibration or other factors.

The correct answer is to refer to the structure repair manual. This is because the manual will provide specific instructions and guidelines on how to repair the composite structure, including the appropriate wrap direction for the top layer of fabric. The manual will have detailed information and diagrams to ensure that the repair is done correctly and effectively.

A sake proof washer is a type of washer that is designed to prevent loosening or rotation of a fastener. The saw tooth serrations on the washer create a locking effect when it is tightened against a surface, providing resistance to vibration and preventing the fastener from coming loose. The saw tooth serrations act like tiny teeth that dig into the surface, increasing the friction and ensuring a secure connection. This feature makes the washer effective in applications where maintaining tightness is crucial, such as in machinery or automotive assemblies.

Turnbuckles are the correct answer because they are devices that have LH (left-hand) as well as RH (right-hand) threads. LH threads are tightened by turning counterclockwise, while RH threads are tightened by turning clockwise. Turnbuckles are commonly used in applications where tension needs to be adjusted, such as in rigging systems or for tightening cables or wires. The LH and RH threads allow for easy adjustment and tightening of the turnbuckle based on the specific requirements of the application.

Fretting corrosion is caused by the slight relative motion between two mating surfaces. It occurs when there is repetitive contact and rubbing between the surfaces, leading to the formation of wear particles and the degradation of the material. This type of corrosion is often observed in mechanical systems such as joints, connectors, and fasteners, where the movement between the surfaces is minimal but continuous. Fretting corrosion can result in material loss, surface damage, and the formation of pits or cracks, which can compromise the integrity and functionality of the components.

Corrosion on aluminum alloy is typically identified by the presence of a white color. This white film is a result of oxidation and the formation of aluminum oxide on the surface of the alloy. As aluminum reacts with oxygen in the air, it forms a protective layer of aluminum oxide, which appears as a white powdery substance. This white corrosion is a common indication of deterioration and can be used to identify the presence of corrosion on aluminum alloys.

The American Wire Gauge (AWG) is a standard system used to measure the size of electrical wire. The lower the AWG number, the larger the wire diameter and the greater the current it can carry. Therefore, AN-16 would be able to carry the greatest current load among the given options because it has the lowest AWG number.

The left hand threaded end of a turnbuckle can be identified by a groove or knurl on the barrel. This feature distinguishes it from the right hand threaded end, which typically does not have this groove or knurl. The groove or knurl provides a visual indicator for users to easily identify and differentiate between the two ends of the turnbuckle.

The correct answer is to prevent the rivets from age hardening. Age hardening is a process in which a metal alloy becomes harder and stronger over time due to the precipitation of solute atoms. By keeping the 2024 DD alloy rivets in refrigeration, the temperature is lowered, which slows down the aging process and prevents the rivets from becoming overly hardened. This helps to maintain the desired properties and performance of the rivets.

The efficiency of a pulley system is defined as the ratio of output work to input work. In this case, the efficiency is given as 80%. The velocity ratio is the ratio of the distance moved by the effort to the distance moved by the load. Given that the velocity ratio is 15, it means that for every 15 units of distance moved by the effort, the load moves 1 unit of distance.

To calculate the force required to lift the load, we can use the formula:

Force = (Load / Velocity Ratio) / Efficiency

Plugging in the values, we get:

Force = (290 kg / 15) / 0.8 ≈ 24.2 kg

Therefore, the force required to lift the load of 290 kg is approximately 24.2 kg.

Fasteners in the AN, NAS, MS series use UNC (Unified Coarse) or UNF (Unified Fine) threads. These threads are standardized and widely used in the United States for fasteners. They are not interchangeable with metric threads, which have a different thread pitch and diameter. Additionally, the fasteners in the AN, NAS, MS series do not have BA (British Association) and BSF (British Standard Fine) threads, as these are British thread standards. Therefore, the correct answer is that fasteners in the AN, NAS, MS series use UNC or UNF threads.

The main purpose of a matrix in a composite is to transfer stresses to the fiber. In a composite material, the matrix acts as a medium that holds the fibers together and distributes external loads or stresses to the fibers. The matrix material is typically weaker and more ductile than the fibers, allowing it to absorb and transfer stresses to the stronger fibers, thereby enhancing the overall strength and performance of the composite material.

Age-hardening of a metal is a process where the metal is quenched after heat treatment and left for some time to develop its properties. This process allows the metal to undergo precipitation hardening, where small particles form within the metal's microstructure, increasing its strength and hardness. The time allowed for aging can vary depending on the specific metal and desired properties.

Copper conductors used in aircraft electrical systems are coated with thin nickel or silver to prevent oxidation and facilitate soldering. Oxidation can occur when copper is exposed to air and moisture, which can degrade the conductivity of the conductor. By coating the copper with nickel or silver, it creates a barrier that prevents oxidation from occurring. Additionally, the coating helps to facilitate soldering by providing a surface that is easier to bond with other components or wires.