Common Core 107
Aviation Fundamentals
107.1 Describe the following terms pertaining to motion:
Inertia- The willingness
of an object to remain at rest or to continue in motion unless acted
upon by an outside force.
107.2 Define the following laws of motion:
Newtons First Law: According
to Newton's first law of motion (inertia),
an object at rest will remain at rest, or an object in motion will
continue in motion at the same speed and in the same direction, until
acted upon by an outside force.
107.3 Define Bernoulli's principle.
The principle states that when a fluid flowing through a tube reaches a constriction or narrowing of the tube, the speed of the fluid passing through the constriction is increased and its pressure decreased. The general lift of an airfoil is dependent upon the airfoil's being able to create circulation in the airstream and develop the lifting pressure over the airfoil surface. As the relative wind strikes the leading edge of the airfoil, the flow of air is split. Part is deflected upward and aft, and the rest is deflected down and aft. Since the upper surface of the wing has camber or a curve on it, the flow over its surface is disrupted, and this causes a wavelike effect to the wing. The lower surface is relatively flat. Lift is accomplished by the difference in the airflow across the airfoil.
107.4 Discuss the following weather warnings and their effect on naval aviation:
Wind warning- Please
note: one knot equals approximately 1.1 mile-per-hour. Destructive
weather poses a significant threat to personnel, aircraft, ships,
installations, and other resources. Adequate and timely weather
warnings, coupled with prompt and effective action by commanders
concerned, will minimize loss and damage from destructive weather.
107.5 Describe the following aerodynamic terms:
Lift- The force that
acts, in an upward direction, to support the aircraft in the air. It
counteracts the effects of weight. Lift must be greater than or equal
to weight if flight is to be sustained.
107.6 State the three primary movements of aircraft about the axis.
Pitch - The movement of the aircraft about its lateral axis. The up and down motion of the nose of the aircraft.
- Yaw - The movement of the aircraft about its vertical axis. The drift, or right or left movement of the nose of the aircraft.
- Roll - The movement of the aircraft about its longitudinal axis. The movement of the wing tips; one up and the other down.
107.7 Identify and state the purpose of the primary flight controls for:
1. Fixed wing aircraft- Lateral control (ELEVATOR), Longitudinal control (AILERON), and Directional control (RUDDER)
2. Rotary wing aircraft- Cyclic Pitch, Collective Pitch, and Rotary Rudder
107.8 State the purpose of the following flight control surfaces:
Flap- Gives the aircraft
extra lift. The purpose is to reduce the landing speed, thereby
shortening the length of the landing rollout. They also facilitate
landing in small or obstructed areas by permitting the gliding angle
to be increased without greatly increasing the approach. The use of
flaps during takeoff serves to reduce the length of the takeoff run.
107.9 Explain the term angle of attack.
The angle at which a body, such as an airfoil or fuselage, meets a flow of air.
107.10 Explain the term autorotation.
A method of allowing a helicopter to land safely from altitude without using engine power by making use of the reversed airflow up through the rotor system to reduce the rate of descent. Accomplished by lowering collective pitch lever to maintain rotor rpm while helicopter is decreasing in altitude, then increasing collective pitch at a predetermined altitude to convert inertial energy into lift to reduce the rate of descent and cushion the landing.
107.11 State the components of a basic hydraulic system.
A reservoir to hold a supply of hydraulic fluid.
- A pump to provide a flow of fluid.
- Tubing to transmit the fluid.
- A selector valve to direct the flow of fluid.
- An actuating unit to convert the fluid pressure into useful work.
107.12 Describe and explain the purpose of the main components of landing gear.
Shock Strut Assembly - Absorbs the shock that otherwise would be sustained by the airframe.
- Tires - Allows the aircraft to roll easily and provides traction during takeoff and landing.
- Wheel brake assembly - Used to slow and stop the aircraft. Also used to prevent the aircraft from rolling while parked.
- Retracting and extending mechanism - All the necessary hardware to electrically or hydraulically extend and retract the landing gear.
- Side struts and supports - Provides lateral strength/support for the landing gear.
107.13 State the safety precautions used when servicing aircraft tires on aircraft.
Modern aircraft wheels and tires are among the most highly stressed parts of the aircraft. High tire pressure, cyclic loads, corrosion and physical damage contribute to failure of aircraft wheels. Always approach the tires from fore and aft. When inflating, stand off to the side.
107.14 State the 5 basic sections of a jet engine.
The intake which is an opening in the front of the aircraft engine that allows outside or ambient air to enter the engine.
- The compressor which is made of a series of rotating blades and a row of stationary stator vanes. The compressor provides high-pressure air to the combustion chamber (or chambers).
- The combustion chamber where fuel enters and combines with the compressed air.
- The turbine section which drives the compressor and accessories by extracting some of the energy and pressure from the combustion gases.
- The exhaust cone which is attached to the rear of the engine assembly and eliminates turbulence in the emerging jet, thereby giving maximum velocity.
107.15 Describe the following engine systems:
Turbojet- Projects a
column of air to the rear at an extremely high velocity. The
resulting effect is to propel the aircraft in the opposite or forward direction.
107.16 State the purpose of an afterburner.
Used during takeoff and combat maneuvering to boost the normal thrust rating of a gas turbine engine through additional burning of the remaining unused air in the exhaust section.
107.17 State the NATO symbols for the following fuels and briefly explain the characteristics and reasons for the use of each:
JP4- Has a flamespread
rate of 700-800 feet per minute and a low flashpoint of -10 degrees F
or -23 degrees C. Never used on ships. Use of JP4 will normally cause
an engine to operate with a lower exhaust gas temperature (EGT),
slower acceleration, and lower engine RPM.
107.18 Describe the 3 hazards associated with jet fuel.
Eye, skin irritant, inhalation hazard.
107.19 Describe the symptoms of fuel vapor inhalation.
The symptoms include nausea, dizziness, and headaches. Fuel vapor inhalation can cause death.
107.20 Explain the purpose of the Auxiliary Power Unit (APU).
These power units furnish electrical power when engine-driven generators are not operating or when external power is not available. Most units use a gas turbine to drive the generator. The gas turbine provides compressed air for air conditioning and pneumatic engine starting. This makes the aircraft independent of the need for ground power units to carry out its mission.
107.21 Identify the reasons for and methods of Non-Destructive Inspection (NDI)
It is essential that defects be found and corrected before they reach catastrophic proportion. NDI can provide 100 percent sampling with no affect to the use of the part or system being inspected. Methods used may include visual, optical, liquid penetrate, magnetic particle, eddy current, ultrasonic, radiographic, etc. NDI is the practice of evaluating a part or sample of material without impairing its future usefulness.
107.22 Discuss icing and its effects on the performance of naval aircraft.
Ice on the airframe decreases lift and increases drag, weight, and stalling speed. The possibility always exists that engine system icing may result in loss of power. Icing can cause: loss of engine power, aerodynamic efficiency, loss of proper operation of control surfaces, brakes and landing gear, loss of outside vision, false instrument indications, and loss of radio.
107.23 State the purpose of the following:
Pitot-static- The
pitot-static system in an aircraft includes some of the instruments
that operate on the principle of the barometer. It consists of a
pitot-static tube and 3 indicators, all connected with tubing that
carries air. The three indicators are the altimeter, airspeed
indicator, and the rate-of-climb indicator. Each operates on air
taken from outside the aircraft during flight. The tube or line from
the pitot tube to the airspeed indicator applies the pressure of the
outside air to the indicator.
107.24 State the purpose of the following armament:
Bombs- Any weapon other
than a torpedo, mine, rocket or missile, dropped from an aircraft.
Bombs are free-falling explosive weapons and may be unguided or
"smart" or guided. Designed for release over enemy targets
to reduce and neutralize the enemy's war potential by destructive
explosion, fire, nuclear reaction, etc.
107.25 Explain the purpose of the following:
Circuit breaker- A
protective device that opens a circuit when the current exceeds a
predetermined value. Circuit breakers can be reset.
107.26 Explain the following avionics terms:
Note: Ohm's Law states E=IR
Voltage- The "driving
force" behind current. Voltage, as applied to Ohm's Law, can be
stated to be the base value in determining unknown circuit values.
Designated by the letter (E).