Fasteners are an important part of any aviation machinery. They have to be able to withstand extreme circumstances and remain reliable in all situations. In the aerospace industry, fasteners are used in countless different capacities. Nuts, a very commonly used fastener, are as varied as their uses. The four most common types of nuts are acorn nuts, square nuts, wing nuts, and weld nuts. This blog will explain each of these types in detail.

Acorn Nuts

Acorn nuts are also known as cap nuts. They are designed so that one end of the nut is covered by a dome in order to keep the screw covered. You will most likely find these nuts used in car wheels. When using these nuts, be aware of what length of screw will protrude above the nut. It can not be higher than the total height of the dome, otherwise it will be difficult to put the nut in place.

Square Nuts

Square nuts are easy to differentiate from others due to their square body. Most other types of nuts are either round or hexagonal in shape. Square nuts are most often used to fasten small items, for instance, during electrical installation. Their small size also lends them to use in tight spaces.

Wing Nuts

Wing nuts have wing-like structures on their surfaces. This makes them very easy to wind or unwind by hand. Because of this, wing nuts are commonly used in cases where regular removal and re-fastening is expected. Their ease of removal also means they are not strong enough to withstand large forces and therefore are not usable in heavy duty work.

Weld Nuts

Weld nuts are probably what you imagine when you picture a nut in your head. They are designed to have a protrusion from the surface of the nut. Just as the name implies, these nuts are typically welded after being put in place. Because of this, they are the most permanent nuts.

At NSN Parts Hub, owned and operated by ASAP Semiconductor, we can help you find any of the unique fasteners for the aerospace, civil aviation, and defense industries. We’re always available and ready to help you find all the parts and equipment you need, 24/7-365. For a quick and competitive quote, email us at sales@nsnpartshub.com or call us at 1-269-264-4495.



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Managing and operating an aircraft takes serious effort. From keeping up with FAR and FAA policies to ensuring that you’ve hired and trained a certified cabin crew, there is a lot that goes into overseeing an aircraft. Whether you’re the sole owner and supervisor of your aircraft or you’re delegating specific tasks to different teams of professionals, it’s crucial to know what kind of maintenance goes into keeping your fleet in tip top shape. Read on below for some helpful aircraft maintenance tips:

  1. Ensure Your Tires Are In Ideal Condition

Your aircraft may not utilize its Aircraft tires for long periods of time, but they run at high speeds and carry a ton of weight which means they can get worn down easily. As they are the “legs” of the plane, it's important to regularly check on tire pressure and their overall condition.

  1. Clean Your Instrument Panel

The instrument panel is a major asset to operating the plane and any smudges, spills, cracks or stains on this panel could potentially obstruct the view of the altitude indicator and other information important for the pilot crew. Most instrument panels now are made of glass so investing in an aviation glass cleaning item is beneficial. 

  1. Maintain / Acquire Maintenance Management Solution

An aviation maintenance management solution is often used with entire aircraft fleets but they can also be useful for private aircraft owners. The maintenance management system is designed to make maintenance for your aircraft easier to track.

  1. Make Sure Aircraft is Regularly Serviced

As important as it is for your car to receive regular maintenance work, it’s even more important for your aircraft to have it done. When getting work done, be sure to rely only on experts in their field to check for things like spark plugs, fittings, and the engine.

  1. Be On High Alert For Something Amiss

This is what will separate a meets-expectation aircraft manager from a superior one. Oftentimes, when some part of the aircraft is not working, it will go unnoticed until inspection. However, if you are cognizant of your aircraft, you would notice anything strange prior to routine tests and checkups.

  1. Obtain Clean Fuel

This is an important bit of advice that, unless you’re an expert at it, you might want to delegate to a professional. Your plane runs on this, so keeping clean, good-quality fuel should be a priority. Our experts at NSN Parts Hub can direct you to the best fuel for your aircraft.

  1. Keep Aircraft Exterior Clean

Last but not least, you’ll want to invest in the right cleaning products that will keep the exterior of your aircraft clean. A proper pressure washing system will certainly help but certain parts do require a specialized product.

At NSN Parts Hub, owned and operated by ASAP Semiconductor, we can help you find all the unique parts for the aerospace, civil aviation, and defense industries. Along with being the primary provider of aircraft and defense industry parts, our team of professionals at NSN Parts Hub are knowledgeable on managing aircraft maintenance. We’re always available and ready to help you find all the parts and equipment you need, 24/7-365. For a quick and competitive quote, email us at sales@nsnpartshub.com or call us at +1-269-264-4495.



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An aircraft requires three things to take flight and maintain it: lift, propulsion, and control. Lift is provided by the aircraft’s wings, and propulsion by its engines, but establishing control is the most challenging to maintain.

Control of an aircraft is broken down into three different axes, all based on the aircraft’s center of gravity. These axes are:

  1. The longitudinal axis, which runs from nose to tail. It is also called the axis of roll, as it involves one wing rolling up while the opposite rolls down.
  2. The lateral axis, which runs from wingtip to wingtip. Also called the axis of pitch, the lateral axis determines if the aircraft’s nose is pointed up or down.
  3. The normal axis, which runs from the top of the cabin to the bottom of the landing gear. Also called the axis of yaw, it relates to the nose pointing left or right.               

Modern conventional aircraft have control surfaces for each of these axes. The ailerons, panels in the trailing edge of the wings, adjust the aircraft’s longitudinal axis. Panels in the tail (or in some aircraft the entire tail) act as a horizontal elevator, controlling the aircraft’s pitch. Lastly, a vertical tail plane features a aircraft rudder (like a boat’s) that controls the aircraft’s axis of yaw.

Other control systems and methods have been invented, of course. Some combine control elements like the ailerons and elevators into a single control surface called a taileron, while others warp the entire wing’s shape to provide longitudinal control, but these methods are not as prevalent.

Stability refers to the aircraft’s ability to return to its original equilibrium state after a small displacement, without the pilot interfering. In other words, if the plane is disturbed in any of its axis, such as by turbulence, it will return to its original orientation. This is referred to as static stability. Dynamic stability is when an aircraft continuously tries to return to its original state, and may overcorrect and oscillate, or diverge completely and behave uncontrollably.

Longitudinal stability is the stability around the pitching axis. It is influenced by both the aircraft’s center of gravity, and the center of pressure. The further forward towards the nose the center of gravity is, the more stable the aircraft is with respect to pitching. However, the further forward the center of gravity is, the more difficult the aircraft is to control. Meanwhile, the center of pressure is the point that aerodynamic lift forces are assumed to act if they were combined onto a single point. If the center of pressure does not match the center of gravity, pitching movements will be induced around the center of gravity. The problem is that the center of pressure is not static and moves in flight depending on the angle of incidence on the wings. The pilot’s control over longitudinal stability comes with the design of the tail plane and elevators. By using the elevators, the pilot can correct undesired pitching motions.

Lateral stability is the stability of the aircraft when rolling one wing down and the other up. As it does this, the wings are no longer generating equal amounts of lift. This creates a vertical lift component in the direction of gravity, and a horizontal load component, causing the aircraft to sideslip. A sideslip load can contribute to returning the aircraft to the original configuration and can be achieved with wings that are either upward-inclined or swept-back.                 



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The rotor shaft of a helicopter is a center of activity, which is all carefully considered and accounted for during flight. Unlike airfoils on fixed wing aircraft, the propellers on helicopters move back, forth, up, and down during operation. With all this movement, it is important that the propeller movement is controlled. Various pieces of hardware such as bearings, fasteners, and dampers all help to stabilize the propeller movement. This blog will focus on the importance of dampers.

To begin, dampers are devices that are designed to prevent any resonance issues. Found in the lead/drag hinge, the dampers effectively absorb movement and therefore lessen the side effects of the rotational movement of the propellers on the helicopter’s center of gravity.

The lead/lag movement of propellers refers to the back and forth movement of the helicopter’s propellers. As the rotor spins, each blade responds to inputs from the control system to enable aircraft control. The propellers begin to flap upwards as the lift on a blade increases. In turn, the helicopter’s center of gravity shifts as a result of the individual movement of each propeller. Change in movement is usually a cause and effect chain. In this instance, the change in the center of gravity alters the speed of the whole Dampers rotor system. The lead/lag motion therefore needs to be regulated to ensure that the pilot has enough control over the rotor system. This is particularly important during moments when the flapping force of the propellers is stronger as a result of a maneuver.

Dampers are manufactured in various shapes and use various ways to absorb pressure. Hydraulic dampers for example, include a pressure pipe, piston rod, and the dampening medium of oil. The most common type of damper that is used in the rotor shaft are elastomeric or visco-elastic. Cylindrical in shape, elastomeric dampers are composed of two outer metal plates that sandwich together smaller metal plate, each separated by elastomeric layers such as molded silicone. The addition of elastomeric material is vital as the material has a high load strength and high tear rating. Under the stress of the propeller’s motion, the damper’s form stays intact.


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Hydraulic systems are a fundamental component in the design and construction of modern aircraft. As the engineering of hydraulic systems evolved over time, and the technology became more elaborate, aircraft designers began implementing hydraulic systems for many more aircraft functions. This is due, in part, to the fact that hydraulic systems are economically friendly to install, easy to maintain, and can still perform in the most demanding in-flight conditions. Modern aircraft use hydraulic systems to support for the operation of several flight-critical functions.

The most common application of aircraft hydraulic systems are flight control surfaces, landing gear, and brakes. The fundamentals of aircraft hydraulics are virtually the same regardless of different aircraft styles. Whether it be a small single-engine propeller-powered plane or a multi-engine jet transport, the design of the hydraulic maintains a structural integrity. Hydraulics are designed to be lightweight, easy to install, and simple to maintain. Hydraulics function efficiently with very little friction-related loss of fluid.

Depending on the purpose that the hydraulic system is intended to achieve, it is not uncommon to need to install redundant systems to facilitate safe operation of the aircraft. This can aid in the event that a hydraulic system fails. Many aircraft hydraulic systems share the same basic foundation. This includes a pump, reservoir, actuating cylinder, pressure relief valve, and heat exchanger. Regardless of the scope and scale of the system itself, these main elements will always be present.

The process in which aircraft hydraulic system operates is simple. A pressurized liquid is used to move a specific part of the vessel from one position to another. Depending on the weight of an aircraft, the operating pressure can vary from a few hundred pounds per square inch to a whopping five thousand pounds per square inch. When the pump is activated, it pressurizes the system, which puts the actuator in motion. The directional movement of the actuator is transferred to another surface, such as landing gear, brakes, even a cargo ramp. Pressure is then released from the system to reverse the movement.

Aircraft hydraulic systems have efficient responses to control inputs. This allows the pilot to execute flight control functions with ease, without worry, and most importantly, safely.


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An aircraft heating system is integral for the safe operation of an aircraft. In the duration of its flight cycle, an aircraft will encounter volatile temperature changes and a heating system can help ensure all aircraft components maintain their necessary temperature for efficient and reliable operation. Two heating systems that are frequently utilized in aviation are exhaust heaters and combustion heaters. The systems share one similarity— both utilize the heating of ambient air or ram air. Let’s take a look at how these heater systems work.

Exhaust heaters are most commonly seen on smaller, single-engine aircraft. The unit is installed around part of the engine’s exhaust system and is sometimes referred to as an exhaust shroud heater. An exhaust manifold delivers warm exhaust into the metal shroud. Ram air is also brought into the shroud from outside of the aircraft. The air is warmed by the exhaust, then routed through a heater valve to the cabin. In some models, the air is routed to the carburetor as well. Exhaust is then transferred to an outlet. 

This type of heater doesn’t need an independent electrical system or engine power to operate, making it efficient in a small aircraft. However, this system is hazardous in the event of failures or defects within its hardware— a small crack in the shroud or exhaust manifold has the potential to leak lethal levels of carbon monoxide into the cabin. This system requires rigorous maintenance efforts to keep it operating safely.

Combustion heaters are seen on various aircraft sizes. A combustion system operates independently from the engine and only relies on engine fuel from the main fuel system. The system incorporates a ventilating air system, fuel system, and ignition system to heat various components of an aircraft. In order to heat incoming air from the ventilating system, the combustion unit integrates an independent combustion system within a shroud in a heater unit, where fuel and air are mixed and ignited within an inner chamber.

Air intended for combustion is provided by a blower, which pulls air from outside the aircraft and ensures the air is pressurized to the correct specifications. Ram air is collected when the aircraft is grounded, through a ventilating air fan. The ram air is circulated around the combustion chamber and outer shroud, allowing it to heat through convection. Following this process, the heated air is then directed to the cabin. Exhaust from the same process is expelled from the aircraft. 

 A combustion unit is extremely versatile, which is why it is used on a variety of aircraft. Most are controlled and monitored by a pilot through a cabin heat switch and thermostat and incorporate various redundant safety features. These might include an overheat switch or duct limit.


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Avionics test methods are typically restricted to singular fashion testing. This defines the removal of a faulty avionic component from the aircraft, usually an avionics box, in order for it to be tested at a repair station. The main issue with this process is that it cannot accurately reflect the malfunctioning unit in tandem with its associated aircraft systems. Therefore, if a problem does not occur during testing and cannot be recreated by the service facility or an avionics technician, it is classified as a No Faults Found (NFF) case. 

Upon this occurrence, the said components have to be replaced. In commercial aviation, this process and potential replacement of avionics parts and systems can cost an airline up to 250,000 dollars a year, per aircraft. Paired with the gradual conversion of avionics from copper to fiber-optic technology, this predicament poses the demand for whole new methods of testing. 

Fiber optics are thin strands of plastic or glass, with a diameter averaging that of a human hair. Fiber optic wires are made up of bundles called optical cables that communicate light signals between systems. A fiber optic cable consists of three main parts. The core, which is made up of the thin fibers previously mentioned. Core fibers are contained within an outer optical material called cladding, whose purpose is to reflect any light leakage back into the core. These cables are coated with a plastic, called buffer coating, that surrounds the fiber optic bundles and protects them from corrosion and damage. 

Fiber optics require an optical transceiver in order to convert the optical signals into electrical signals, and vice versa. In the tumultuous environment of an aircraft, vibration and temperature changes can cause this device to degrade at a fast rate. This damage creates a predicament where cables may start to fail in ways that are difficult to detect, such as degraded output of power or degraded receiver sensitivity within a box. 

The integration of a new fiber optic system alone, much like that of a new electronic assembly, can cause failures in compatibility that are challenging to isolate. Bus functions and fiber optics systems interact with one another and function simultaneously within a network in real-time. Due to this exchange, it is imperative that both systems are tested together in the event of a failure. 

A possible solution for the complications of testing a fiber optics system, is a switch tester. This device is capable of checking optical power at sending and receiving points within a malfunctioning fiber optic assembly. Testing of this nature can isolate errors that originate from an optical transceiver using high-density switching. Some models of this device, in addition to this capability, have the capacity to transmit data to bus-test instruments while connected to the unit being tested. This allows the device to conduct a stress-test on Ethernet and Fiber Channels while they are in their typical interaction with the fiber optic system, in order to locate any errors within the communication networks. To add to its capabilities, this mechanism can also be utilized on the aircraft itself, or in a factory test, greatly reducing the risk of an NFF fiber optic component.


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Although advancements in aircraft technology are designed to create a more efficient and reliable flight experience, most aircraft still rely on six traditional instruments known as the “six-pack”. Like how the core of the human body is necessary for maintaining posture and balance, the “six-pack” is necessary for informing the pilot of vital information regarding the status of the aircraft.

These six instruments are classified into two separate categories based on their respective operating mechanisms: static instruments and gyroscopic instruments. And each classification has three instruments. Static instruments operate based on comparing the pressure of an enclosed capsule to fluctuating environmental pressure to indicate things like speed and altitude. Gyroscopic instruments are based on gyroscopes which indicate orientation and direction. Gyroscopic instruments can be found in vacuum or electric driven variations.

The static instruments include the altimeter, airspeed indicator, and vertical speed indicator (VSI). As the name suggests, the altimeter relays information on the altitude, or vertical distance of the aircraft. The altimeter works by comparing the static pressure of an enclosed capsule to the fluctuating pressure of the aircraft as it ascends or descends. This is then translated to a gauge display to indicate the vertical distance of the aircraft over the mean sea level. The airspeed indicator works in a similar fashion but differs by comparing ram air pressure to a constant air pressure in order to measure the speed of the aircraft. Temperature and density, which are components in measuring pressure, are both accounted for when measuring true airspeed— the actual speed of the aircraft. The VSI operates similarly to the previous two in order to measure the rate of ascent or descent of the aircraft, which is measured in feet per minute (fpm). However, the VSI differs from the other two in that it is more sensitive to changes in pressure, which makes it more sensitive to abrupt changes in pressure like in turbulence.

Gyroscopic instruments include heading indicators, attitude indicators, and turn coordinators. Turn coordinators indicate the rate of turn or roll of the aircraft, which is measured through a one-dimensional gyroscope which leans either to the left or right. Heading indicators inform pilots on what direction the aircraft is heading on a two-dimensional gyroscope. Rather than through typical cardinal directions, the heading indicator measures the direction of the aircraft on a 360-degree compass. Attitude indicators tell the pilot whether the aircraft is ascending, descending, turning, or maintaining a level altitude; they operate based on a three-dimensional gyroscope with a center that maintains a constant position while the outer rings of the gyroscope revolve around it to simulate a horizon and the aircraft’s direction. 
The names and different classifications of the various instruments are very reflective on the functions and operational methods of each instrument. Although advanced technology has replaced and automated the functions of these instruments, they act as a failsafe and because of this they are able to maintain their rightful place in the dashboard of an aircraft. 

At NSN Parts Hub, owned and operated by ASAP Semiconductor, we can help you find all the aircraft altimeters, airspeed indicators, or aircraft cockpit parts you need, new or obsolete. As a premier supplier of parts for the aerospace, civil aviation, and defense industries, we’re always available and ready to help you find all the parts and equipment you need, 24/7x365. For a quick and competitive quote, email us at sales@nsnpartshub.com or call us at +1-269-264-4495


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