Term
| What is the most important law applicable to the study of electricity? |
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Definition
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Term
| What are the elements of Ohm's Law? |
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Definition
| Voltage (E), current (I), and resistance (R) |
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Term
| What are the sources of electrical power? |
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Definition
| Mechanical (generator), chemical (Battery), Photoelectric (light), and thermal (heat) |
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Term
| What does an electrical circuit consist of? |
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Definition
| source, resistance in form of power consuming device and a conductor. (Wires) |
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Term
| What represents capacitance in an AC circuit? |
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Definition
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Term
| What is the function of a capacitor? |
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Definition
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Term
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Definition
| A voltage that is induced by magnetic flux lines in a coil in an AC circuit. The induced voltage is oposite in direction to the applied voltage, and opposes any change in alternating current. |
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Term
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Definition
| The opposition for AC to flow caused by the combined effect of resistance, inductive reactance, and capacitive reactance in an AC circuit |
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Term
| What is the unit of memasurement of power in a DC circuit? |
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Definition
| The watt. Amperes time volts equals watts (P = I x E) 746 watts equals one horsepower. |
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Term
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Definition
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Term
| In a DC circuit, what occurs when voltage is increased while resistance remains constant? |
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Definition
| There will be an increase in current. |
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Term
| What are the three types of DC electrical circuits? |
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Definition
| They are series, parallel, and series parallel |
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Term
| A 24 volt lead-acid battery has how many cells? |
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Definition
| it has 12 cells. Each cell is rated at 2 volts. |
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Term
| What should be the specific gravity of the electrolyte in a fully charged lead-acid battery? |
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Definition
| It should be between 1.275 and 1.300 |
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Term
| What instrument is used to determine the seccific gravity of electrolyte in a lead acid battery? |
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Definition
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Term
| Why can't a hydrometer be used to determine the charge of a nickel-cadmium battery? |
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Definition
| The specific gravity of the electrolyte in a nickel-cadmium battery does not change appreciably during charge or discharge of the battery |
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Term
| When using a hydrometer to check the charge of a lead-acid battery, at what temperatures must a correction factor be applied to the reading? |
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Definition
| Adjustments must be made if temperature of the electrolyte is above 90F or below 70F |
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Term
| What is electromagnetic induction? |
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Definition
| It is the transfer of electical energy by means of a magnetic field(lines of flux). This is the principle of transformer operation |
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Term
| How are battery compartments protected against corrosion? |
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Definition
| They are coated with a special corrosion resistant paint such as bituminous paint. |
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Term
| What should be the correct electrolyte level in a properly seviced battery? |
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Definition
| It should be approx 3/8 inched above the plates, the electrolyte level should be up to the hole in the baffle plate in each cell |
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Term
| What is paralleling generators? |
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Definition
| This is when two or more generators are oerated at the same time to supply power for a load that must be shared equally. |
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Term
| Describe a no-trip circuit breaker (tri free). |
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Definition
| A "trip free" breaker makes it impossible to manually hold the circuit closed when excessive current is flowing. (Pops when circuit gets hot and can't reset until it's cooled off) |
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Term
| Can you store Ni-cad and Lead-acid batteries together? |
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Definition
| No, the fumes from the lead-acid battery can contamminate the electrolyte in the ni-cad battery. |
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Term
| WHat type of lines are used on aircraft drawings to indicate hidden views, alternate positions and center lines? |
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Definition
A hidden view line is a medium width line made up of "short dashes". It reresents an edge that cannot be seen when looking at the part from a secific position.
Alternate Position lines are medium width lines compposed "one long and two short evenly spaced dashes". They are used to sho alternate postion of a part or the realative position of a missing part.
Center lines are comosed of "alternate long and short dashes". indicate the center. |
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Term
| Define "tolerance" as used in aircraft drawings. |
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Definition
| The difference bewtween the plus and minus allowable dimension of a part. |
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Term
| Define "clearance" as used in acft drawings. |
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Definition
| Clearance is the dimension given for the space between parts |
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Term
| What information is given in the title block of a blueprint? |
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Definition
| The drawing number, the name of the part or assembly, the scale, the date, the name of the firm, the name of the draftsman, the checker, and the approving official. |
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Term
| Why are dimensions used, and how are they shown on acft drawings? |
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Definition
| Dimensions are solid narrow lines, broken at the midpoint for the insertion of measurements. They are used to indicate the size of the object. |
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Term
| How can a change to an acft drawing be identified? |
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Definition
| By its revision letter. The revision letters are usually listed in a table next to the title block or at one corner of the drawing. |
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Term
| What is a "bill of material" associated with aircraft blueprints? |
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Definition
| It is a list of materials and parts neccesary for fabrication or assembly of a component or system |
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Term
| Why are symbols used when drawing acft blueprints? |
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Definition
| Symbols are a type of shorthand used for drawing. They show the characteristics of a component with a minimum amount of drawing. |
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Term
| How many views are required to determine the shape of an object? |
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Definition
| Three views: Front, Top and Side. |
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Term
| What is the datum and its purppose when making weight and balance computations? |
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Definition
| It is an imaginaryvertical line or plain from which measurements are taken both forward and aft to determine the relative location of items in the acft. The datum is always specified by the manufacturer. |
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Term
| What is the purpose of weight and balance control? |
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Definition
| Safety and efficiency in flight |
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Term
| When computing weight and balance, what is the "moment" and how is it obtained? |
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Definition
| a moment is a force which tends to rotate the acft about its center of gravity. It is obtained by multiplying the weight of an item (pounds) by the distance of the item from the datum (inches). It is usually expressed in inch-pounds |
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Term
| What is the "arm" of an item and how is it obtained? |
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Definition
| The arm is the distance (in inches) an item is located either forward or aft of datum. It is obtained either by actual measurement or from the aircraft weight and balance records. |
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Term
| What is the "tare weight", and how is it handled when making weight and balance calculations? |
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Definition
| "Tare" is the weight of extra equipment used for weighing the acft such as chocks, blocks, jacks, and chains. Tare weight must be substracted from the scale readings in order to obtain the actual weight of the acft. |
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Term
| What is meant by minimum fuel and how is it calculated for W/B purposes? |
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Definition
| Minimum fuel is the amount of fuel that should be used in W/B computations when the acft is loaded for an extreme condition check. For a reciprocating engine airplane certified under FAR Part 23, this is the fuel neccesary to operate the engines for one half hour at maximum continuous power |
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Term
| What is meant by residual fuel? |
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Definition
| It is the fuel remaining in the tanks, lines, and engine after draining. Also called "undrainable" or "unusable". It is part of the acfts empty weight. |
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Term
| How would you determine the empty weight and empty weight CG of an acft which is has tricycle landing gear if all weight and balance records are missing? |
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Definition
| Reweigh the acft and calculate the new W/B. |
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Term
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Definition
| Ballast is lead bars, metal plates, shot bags, sand bags, or other items of weight which are placed in the acft to attain a desired CG location |
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Term
| What is difference between fixed wing aircraft and helicopter cg range? |
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Definition
| The CG location in a helo is much more critical than fixed wing. The CG range in some helos is less than 3 inches. |
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Term
| When weighing an acft to determine the empty weight CG, what must you do with reagrd to the equipment which is normally carried in the acft? |
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Definition
| All operations equiment whether it is required, optional, or special equipment must be included in the acft's empty weight |
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Term
| Why do some manufacturers specify an empty CG even thought the acft is not operated at this empty weight? |
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Definition
| When the empty weight CG falls within the empty weight CG range, it is unneccesary to perform a W/B check if standard loading and seating arrangements are used. |
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Term
| Why must the acft category be considered when computing W/B? |
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Definition
| some airplanes are certified in both normal and utility categories. This means that maximum allowable gross weight differs depending on which category the acft will be operated in. |
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