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Showing posts from September, 2019

Fire extinguisher types

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There are 5 main fire extinguisher types – Water, Foam, Dry Powder, CO2 and Wet Chemical. You should have the right types of fire extinguisher for your premises, or you may not meet current regulations. The various types of fire extinguisher put out fires started with different types of fuel – these are called ‘classes’ of fire. The fire risk from the different classes of fire in your business premises will determine which fire extinguisher types you need. You will also need to make sure that you have the right size and weight of fire extinguisher as well as the right kind. You can read more about the current UK extinguisher regulations here. Whilst there are 5 main types of fire extinguisher, there are different versions of both the Water and Dry Powder extinguishers, meaning there are a total of 8 fire extinguisher types to choose from. The 8 types of fire extinguisher are: – Water – Water Mist – Water Spray – Foam – Dry Powder – Standard – Dry Powder – Specialist – Carbon Dioxide

Taxiing Aircraft

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Taxiing Aircraft As a general rule, only rated pilots and qualified airframe and powerplant (A&P) technicians are authorized to start, run up, and taxi aircraft. All taxiing operations are performed in accordance with applicable local regulations. Figure 1 contains the standard taxi light signals used by control towers to control and expedite the taxiing of aircraft. The following section provides detailed instructions on taxi signals and related taxi instructions.  Lights  Meaning Flashing green  Cleared to taxi Steady red  Stop Flashing red  Taxi clear of runway in use Flashing white  Return to starting point Alternating red and green  Exercise extreme caution Figure 1. Standard taxi light signals Taxi Signals Many ground accidents have occurred as a result of improper technique in taxiing aircraft. Although the pilot is ultimately responsible for the aircraft until the engine is stopped, a taxi signalman can assist the pilot around the flight line. In some aircraft configuration

Towing of Aircraft

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Towing of Aircraft Movement of large aircraft about the airport, flight line, and hangar is usually accomplished by towing with a tow tractor (sometimes called a “tug”). [Figure 1] In the case of small aircraft, some moving is accomplished by hand pushing on the correct areas of the aircraft. Aircraft may also be taxied about the flight line but usually only by certain qualified personnel. Towing aircraft can be a hazardous operation, causing damage to the aircraft and injury to personnel, if done recklessly or carelessly. This article outline the general procedure for towing aircraft. However, specific instructions for each model of aircraft are detailed in the manufacturer’s maintenance instructions and are to be followed in all instances.            Figure 1. Example of a tow tractor  Before the aircraft to be towed is moved, a qualified person must be in the flight deck to operate the brakes in case the tow bar fails or becomes unhooked. The aircraft can then be stopped, preventin

Resonant inspection N.D.T

Resonant inspection What is NDT?  Resonant inspection operates by analysing the natural whole-body resonances of a component. This means that an entire component can be inspected in one test for defects, material properties, dimensions, shape and coatings. The dimensions and stiffness of a component determine its natural resonant frequencies. Changes in either dimensions or stiffness will therefore affect the resonant frequencies. The elastic properties of the material of the component, as well as the presence of defects, will affect the stiffness of the component, so any condition that will affect the stiffness or the dimensions of a component will therefore affect the resonances, and therefore be theoretically detectable. It is particularly suited to automation in component manufacturing, and can provide a high-speed automated inspection. By automating the inspection processes, human errors can be eliminated, thereby considerably increasing the reliability of any manual-based inspect

Eddy current Testing NDT

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Magnetism, the underlying principle behind electric motors and generators, relays and stereo speakers, is also the force that enables an important category of NDT tools called eddy current instruments. Eddy current testing is widely used in the aerospace industry and in other manufacturing and service environments that require inspection of thin metal for potential safety-related or quality-related problems. In addition to crack detection in metal sheets and tubing, eddy current can be used for certain metal thickness measurements such as identifying corrosion under aircraft skin, to measure conductivity and monitor the effects of heat treatment, and to determine the thickness of nonconductive coatings over conductive substrates. Both field portable and fixed system instruments are available to meet a wide variety of test needs.  Eddy current NDT can examine large areas very quickly, and it does not require use of coupling liquids. In addition to finding cracks, eddy current can also b