ACS Codes Review

Codes missed from General and Airframe written.

◦ What is meant by resistance in an electrical circuit?

▪ The opposition to the flow of electrons.

◦ What is the basic unit of electrical resistance?

▪ The Ohm.

◦ What four things affect the resistance of an electrical conductor?

▪ The material, the cross-sectional area, the length, and the temperature.

◦ How can you tell the resistance of a composition resistor

▪ By a series of colored bands around one end of the resistor.

◦ What formula is used to find resistance when voltage and current are known?

▪ Resistance = Voltage divided by Current (R=E/I)

◦ What is the formula for power in a DC circuit?

▪ Power = Voltage Times Current (P = I • E)

◦ What is the relationship between mechanical and electrical power?

▪ 1 Horsepower = 746 Watts

◦ What is meant by true power in an AC circuit?

▪ The product of the circuit voltage and the current that is in phase with this voltage.

◦ In what units is true power expressed?

▪ In Watts.

◦ What is meant by apparent power in an AC circuit?

▪ The product of the circuit voltage and the circuit current, without reference to phase angle.

◦ In what units is apparent power expressed?

▪ In Volt-Amps.

◦ What is meant by reactive power in an AC circuit?

▪ The power consumed in the inductive and capacitive reactances in an AC circuit. Reactive power is also called “Wattless Power”

◦ In what units is reactive power expressed?

▪ In Volt-Amps Reactive (VAR), or kilovolt-amps reactive (KVAR).

◦ What is meant by power factor in an AC circuit?

▪ The ratio of true power to apparent power. It is also the ratio of circuit resistance to circuit impedance.

◦ What is meant by the capacity rating of a lead-acid battery?

▪ The number of hours a battery can supply a given current flow.

◦ What electrolyte is used in a lead-acid battery?

▪ A mixture of sulfuric acid and water.

◦ Does the specific gravity of a fully charged lead-acid battery increase or decrease as the battery becomes discharged?

▪ It decreases.

◦ What is the specific gravity of a fully charged lead-acid battery?

▪ Between 1.275 and 1.300.

◦ How many cells are there in a 24-volt lead-acid battery?

▪ 12

◦ What is the range of temperatures of the electrolyte in a lead-acid battery that does not require a correction when measuring its specific gravity?

▪ Between 70° F and 90°F.

◦ How do you treat a lead-acid battery compartment to protect it from corrosion?

▪ Paint it with an asphaltic (tar-base) paint or with a polyurethane enamel

◦ What is used to neutralize spilled electrolyte from a lead-acid battery?

▪ A solution of bicarbonate-soda and water.

◦ How high should the electrolyte level be in a properly serviced lead-acid battery?

▪ Only up to the level of the indicator in the cell.

◦ Why is the closed-circuit voltage of a lead-acid battery lower than its open-circuit voltage?

▪ Voltage is dropped across the internal resistance of the battery.

◦ What gasses are released when a lead-acid battery is being charged?

▪ Hydrogen and oxygen.

◦ What is the electrolyte used in a nickel-cadmium battery?

▪ Potassium hydroxide and water.

◦ Why is a hydrometer not used to measure the state of charge of a nickel-cadmium battery?

▪ The electrolyte of a nickel-cadmium battery does not enter into the chemical changes that occur when the battery is charged or discharged. Its specific gravity does not change appreciably.

◦ Is the electrolyte level of a nickel-cadmium battery lowest when the battery is fully charged or fully discharged?

▪ Fully discharged.

◦ What is a result of cell imbalance in a nickel-cadmium battery?

▪ The low internal resistance allows current to flow between the unbalanced cells and generate heat.

◦ What is thermal runaway?

▪ The large current flow allowed by the low internal resistance cases the cells to produce more heat than they can dissipate. The heat further lowers the internal resistance so more current can flow; this continues until the battery destroys itself.

◦ How may thermal runaway be prevented?

▪ By carefully monitoring the temperature of the cells and controlling the charging current to prevent an excess of current flowing into the battery.

◦ How is it possible to know when a nickel-cadmium battery is fully charged?

▪ Completely discharge the battery and give it a constant-current charge to 140% of its ampere-hour capacity.

◦ What is used to neutralize spilled electrolyte from a nickel-cadmium battery?

▪ A solution of boric acid and water.

◦ What type of drawing depicts electrical components with respect to each other within a circuit?

▪ An electrical schematic

◦ What is meant by Kilowatt?

▪ 1,000 Watts (1 thousand Watts)

◦ What is meant by a Megawatt?

▪ 1,000,000 Watts (1 Million Watts)

◦ What instrument is used to measure current flow?

▪ An Ammeter.

◦ What is a Megohm?

▪ 1,000,000 Ohms. (1 Million Ohms)

◦ What instrument is used to measure electrical resistance?

▪ An Ohmmeter.

◦ When measuring resistance of a component with an ohmmeter, should the circuit be energized?

▪ No, there should be no power on the circuit.

◦ What instrument is used to measure the specific gravity of the electrolyte in a lead-acid battery?

▪ A hydrometer.

◦ How many views can there be on an orthographic projection?

▪ Six

◦ How many views are used to show most objects in an aircraft drawing?

▪ Three (3)

◦ What information is given in the title block of an aircraft drawing?

▪ The name and address of the company who made the part, the name of the part, the scale of the drawing, the name of the draftsman, the name of the engineer approving the part, and the number of the part (the drawing number).

◦ Where is the title block normally located on an aircraft drawing?

▪ In the lower right-hand corner of the drawing.

◦ How can you know that the aircraft drawing you are using is the most current version of the drawing?

▪ By the number in the revision block, and by the log of the most recent drawings.

◦ What is a detail drawing?

▪ A drawing that includes all the information needed to fabricate the part.

◦ What is an assembly drawing?

▪ A drawing that shows all the components of a part in an exploded form. A parts list is included with the assembly drawing

◦ What is an installation drawing?

▪ A drawing that shows the location of the parts and assemblies on the complete aircraft.

◦ What type of drawing is most helpful in troubleshooting a system?

▪ A Schematic Diagram.

◦ What is a block diagram?

▪ A drawing that shows the various functions of a system by a series of blocks. These blocks do not include any detail but instead indicate what happens in each block.

◦ How are dimensions shown on an aircraft drawing?

▪ By numbers shown in the break of a dimension line.

◦ What is the purpose of a center line on an aircraft drawing?

▪ It divides a part into symmetrical halves.

◦ Which has the more critical center of gravity range, an airplane or a helicopter?

▪ A Helicopter.

◦ Where is the center of gravity for most airplanes located in relation to the center of lift?

▪ The CG is normally ahead of the center of lift.

◦ How do you find the moment of an item installed in an aircraft.

▪ Multiply the weight of the item in pounds by its distance from the datum in inches.

◦ Where do you find the arm of an item installed in an aircraft?

▪ In the Type Certificate Data Sheets or the aircraft equipment list.

◦ What is the alloy number of the most commonly used aluminum alloy for aircraft structural use?

▪ 2024-T

◦ What is the alloy number of a high strength aluminum alloy that has zinc as an alloying component?

▪ 7075.

◦ What type of composite material is used when stiffness is the prime requirement?

▪ Graphite (Carbon)

◦ What type of composite material is used when toughness is the prime requirement?

▪ Kevlar (Aramid Fiber)

◦ Why is a piece of steel tempered after it has been hardened?

▪ When steel is hardened, it becomes brittle. Tempering removes some of this brittleness.

◦ How is steel annealed?

▪ It is heated to just above its upper critical temperature until it reaches a uniform temperature throughout, then it is allowed to cool very slowly in the oven.

◦ How is steel hardened?

▪ It is heated to its critical temperature quenched in water, brine, or oil.

◦ What is meant by tempering steel?

▪ The steel is first hardened; then some of the hardness is removed to relieve some of the internal stresses and brittleness.

◦ What is meant by case hardening?

▪ The surface of the metal is hardened by the infusion of carbon or aluminum nitride. The interior of the metal remains strong and tough.

◦ What are two methods of case hardening?

▪ Carburizing and Nitriding.

◦ What is the method of solution heat treatment of an aluminum alloy?

▪ The metal is hardened by heating it in a furnace to a specified temperature and immediately quenching it in water. It is soft when it is removed from a quench, but as it ages it regains its hardness.

◦ What is the method of precipitation heat treating of an aluminum alloy?

▪ The metal is heated and quenched, then it is returned to the oven and heated to a lower temperature. It is held at this temperature for a specified time, then removed from the oven and allowed to cool in still air. This increases the strength and hardness of the metal. Precipitation heat treating is also called artificial aging.

◦ What is another name for precipitation heat treatment?

▪ Artificial Aging.

◦ Identify and explain the differences between heat-treated and non-heat-treated aluminum alloys.

▪ Heat-treated aluminum alloy designations are normally followed with a -T, followed by a number (1-10) that designates the type of heat treat. A common aircraft aluminum alloy is 2024-T3. Heat treated aluminum is stronger than non-heat-treated aluminum.

◦ Why is it important that a piece of aluminum alloy be quenched immediately after it is removed from the heat treating oven?

▪ Any delay in quenching aluminum alloy after it is removed from the oven will allow the grains structure to grow enough that intergranular corrosion is likely to form in the metal.

◦ What is a correct application for self-tapping sheet metal screws on an aircraft?

▪ They may be used to hold nonstructural components onto the aircraft.

◦ 24. How can you tell when a self-locking nut must be discarded? (AM.I.E.K4)

▪ When you can screw the nut onto a bolt without having to use a wrench.

◦ What is a channel nut?

▪ A series of nuts mounted loosely in a channel that is riveted to the aircraft structure. You can install screws in a channel nut without having to hold the nut with a wrench.

◦ Of what two materials are cotter pins made?

▪ Low-carbon steel and corrosion-resistant steel.

◦ 27. What is the smallest size cable that is allowed to be used In the primary control system of an aircraft?

▪ 1/8-inch diameter.

◦ 28. What type of control cable must be used when pulleys are used to change the direction of cable travel?

▪ Extra-flexible cable (7×19).

◦ What is meant by a ratio and how is a ratio expressed? (AM.I.H.K4)

▪ A fraction that compares one number to another; for example, 6:2 is a ratio.

◦ 1. Who is authorized to perform a 100-hour inspection on an aircraft? (AM.I.I.K1)

▪ A certificated Aviation Mechanic who holds an Airframe and Powerplant rating.

◦ 2. Who is authorized to perform an annual inspection on an aircraft? (AM.I.I.K1)

▪ A certificated A&P mechanic who holds an Inspection Authorization.

◦ 3. Can a certificated A&P mechanic supervise an unlicensed person as the unlicensed person performs a 100-hour inspection on an aircraft?

▪ No, a certificated mechanic must personally perform the inspection.

◦ 4. Who Is authorized to rebuild an aircraft engine and issue a zero-time maintenance record?

▪ Only the manufacturer of the engine or a facility approved by the manufacturer.

◦ 5. Which FAR specifies required maintenance records? (AM.I.I.K1)

▪ 14 CFR §91.417 specifies you must keep records of maintenance, preventative maintenance, major repairs and alterations, and 100-hour, annual, and progressive inspections.

◦ 6. Are instructions included In the Federal Regulations mandatory or optional? (AM.l.1.K1)

▪ They are mandatory.

◦ 7. Who Is authorized to approve an aircraft for return to service after a major repair?

▪ An aircraft mechanic holding an Inspection Authorization.

◦ 8. Who is authorized to perform preventative maintenance on an aircraft that is not flown under Part 121, 127, 129, or 135?

▪ The holder of a pilot certificate that flies that particular aircraft.

◦ 9. Who is authorized to rebuild an aircraft engine and issue a zero-time record? (AM.I.I.K1)

▪ The manufacturer of the engine or a facility approved by the manufacturer.

◦ 10. Who is authorized to approve an aircraft for return to service after a minor alteration has been performed on the airframe?

▪ A certificated Aviation Mechanic holding an Airframe rating.

◦ 11. What is the minimum age for an Aviation Mechanic certificate? (AM.I.I.K1)

▪ 18 years.

◦ 12. What are the two ratings that can be Issued to an Aviation Mechanic certificate?

▪ Airframe and Powerplant.

◦ 13. How many months of practical experience is needed to qualify for the Aviation

Mechanic certificate with both Airframe and Powerplant ratings?

▪ 30 months.

◦ 14. What can be used In place of the 30 months of experience to qualify to take the mechanic tests?

▪ A certificate of completion from a certificated aviation maintenance technician school.

◦ 15. What type of experience is required to take the tests for Aviation Mechanic certification?

▪ Practical experience with the procedures, practices, materials, tools, machine tools,

and equipment generally used in constructing, maintaining, or altering airframes, or

powerplants appropriate to the rating sought.

◦ 16. What tests are used to demonstrate that a mechanic applicant has the proper knowledge?

▪ The written knowledge tests.

◦ 17. What tests are used to demonstrate that a mechanic applicant meets the minimum skill requirements?

▪ The oral and practical tests.

◦ 18. What certificate and ratings are required for a mechanic to conduct a 100-hour Inspection and approve the aircraft for return to service?

▪ An Aviation Mechanic certificate with both Airframe and Powerplant ratings.

◦ 19. What certificate and ratings are required for a mechanic to conduct an annual Inspection and approve the aircraft for return to service?

▪ An Aviation Mechanic certificate with an Inspection Authorization.

◦ 20. When, after making a permanent change of address, is the holder of an Aviation Mechanic certificate required to notify the FAA?

▪ Within 30 days.

◦ 21. Is a certificated Aviation Mechanic with Airframe and Powerplant ratings authorized to perform 100-hour and annual inspections?

▪ No. Only 100-hour inspections. Inspection Authorization is required to perform an annual inspection.