What is the main purpose of a servo in an autopilot system?
Correct for displacement of the aircraft about its axis. Change mechanical energy to electrical energy. Move the control surface as commanded.
Grounding is electrically connecting a conductive object to the primary structure. One purpose of grounding is to:
prevent current return paths. allow static charge accumulation. prevent development of radio frequency potentials.
The hydraulic packing seals used in a landing gear shock strut are:
generally designed to be compatible with more than one type of fluid. kept from direct contact with fluid by teflon or nylon backup rings. used only with a specific type of fluid.
Aircraft flight control trim systems must be designed and installed so that the:
pilot can determine the relative position of the trim tab from the cockpit. operating control and the trim tab will always move in the same direction. trim system will disengage or become inoperative if the primary flight control system fails.
What is the purpose of flapper-type check valves in integral fuel tanks?
To allow defueling of the tanks by suction. To prevent fuel from flowing away from the boost pumps. To allow the engine-driven pumps to draw fuel directly from the tank if the boost pump fails.
Oil canning of the sides of aluminum or steel electrical junction boxes is considered to be:
normal operation in vibration prone areas. a shorting hazard. acceptable operation.
A CSD unit drives a generator through the use of:
a synchronous electric motor. an infinitely variable mechanical gearing system. a variable hydraulic pump and hydraulic motor.
Integrated drive generators (I DG) employ a type of high output ac generator that utilizes
brushes and slip rings to carry generated do exciter current to the rotating field. battery current to excite the field. a brushless system to produce current.
Shallow scratches in sheet metal may be repaired by:
burnishing. buffing. stop drilling.
The use of turbine fuels in aircraft has resulted in some problems not normally associated with aviation gasolines. One of these problems is:
increasing viscosity of fuel as fuel temperature lowers at altitude. higher vapor pressure. microbial contaminants.
The purpose of the vertical fin is to provide:
directional stability. longitudinal stability. lateral stability.
(Refer to Figure 1 .) Which of the rivets shown will accurately fit the conical depression made by a 100° countersink? 1. 2. 3.
What is the advantage of a current limiter?
It breaks circuit quickly. It can be reset easily. It will take overload for a short period.
When purging a freon air-conditioning system, it is important to release the charge at a slow rate. What is the reason for the slow-rate discharge?
Prevent the large amount of freon from contaminating the surrounding atmosphere. Prevent excessive loss of refrigerant oil. Prevent condensation from forming and contaminating the system.
Which of the following are the major parts of a dc motor?
1. Armature assembly.
2. Field assembly.
3. Brush assembly.
5. Pole piece.
7. End frame.
1, 2, 3, 7. 2, 3, 4, 5. 3, 5, 6, 7.
What device in a hydraulic system with a constant-delivery pump allows circulation of the fluid when no demands are on the system?
Pressure relief valve. Shuttle valve. Pressure regulator.
Which statement about wood decay is correct?
Decay that occurs before the wood is seasoned does not affect the strength of the finished piece. A limited amount of certain kinds of decay is acceptable in aircraft woods since decay affects the binding between the fibers and not the fibers themselves. Decay is not acceptable in any form or amount.
A transmitter in a fuel pressure warning system serves what function?
Transmits an electrical signal to fluid pressure. Converts fluid pressure to an electrical signal. Transmits fluid pressure directly to the indicator.
In most modern hydraulically actuated landing gear systems, the order of gear and fairing door operation is controlled by:
sequence valves. shuttle valves. microswitches.
After an automatic direction finding antenna has been installed, the:
antenna must be grounded. loop must be calibrated. transceiver must be compensated.
What is the purpose of the oil separator in the pneumatic deicing system?
To protect the deicer boots from oil deterioration. To remove oil from air exhausted from the deicer boots. To prevent an accumulation of oil in the vacuum system.
What is the source of pressure for inflating deicer boots on reciprocating engine aircraft?
Vane-type pump. Gear-type pump. Piston-type pump.
Characteristics of MIL-H-8446 (Skydrol 500 A & B) hydraulic fluid are:
blue color, phosphate ester base, fire resistant, butyl rubber seals. light purple color, phosphate ester base, fire resistant, butyl rubber seals. light green color, phosphate ester base, fire resistant, butyl rubber seals.
The position of the thermostatic expansion valve in a vapor-cycle cooling system is determined by temperature and pressure of the:
freon entering the evaporator. air in the outlet of the condenser. freon in the outlet of the evaporator.
When inspecting a butt-welded joint by visual means,
the penetration should be 25 to 50 percent of the thickness of the base metal. the penetration should be 100 percent of the thickness of the base metal. look for evidence of excessive heat in the form of a very high bead.
In the landing configuration GPWS typically monitors the radio (radar) altimeter; air data computer; instrument landing system; and:
aileron, rudder, and elevator positions. landing gear and flap positions. spoiler, slat, and stabilizer positions.
A typical takeoff warning indication system, in addition to throttle setting, monitors the position of which of the following?
Ailerons, elevators, speed brake, and steerable fuselage landing gear. Elevators, speed brake, flaps, and stabilizer trim. Aerodynamically actuated slats, elevators, flaps, and speed brake.
Repairing advanced composites using materials and techniques traditionally used for fiberglass repairs is likely to result in:
restored strength and flexibility. improved wear resistance to the structure. an unairworthy repair.
Excluding lines, which components are required to make up a simple hydraulic system?
Actuator, pressure reservoir, accumulator, and selector valve. Pump, reservoir, selector valve, and actuator. Pump, reservoir, relief valve, and shuttle valve.
To prevent vapor lock in fuel lines at high altitude, some aircraft are equipped with:
vapor separators. direct-injection-type carburetors. booster pumps.
VHF radio signals are commonly used in:
ATC communications. VOR navigation. both VOR navigation and ATC communications.
What safety device is usually located between the driving unit and hydraulic pump drive shaft?
Thermal relief valve. Pump motor safety switch. Pump drive coupling shear section.
The main system pressure relief valve in a simple hydraulic system equipped with a power control valve should be adjusted:
with the power control valve held in the CLOSED position. while one or more actuating units are in operation. with the power control valve in the OPEN position.
(1) A do selsyn system is a widely used electrical method of indicating a remote mechanical movement or position. (2) A synchro-type indicating system is an electrical system used for transmitting information from one point to another. Regarding the above statements,
only No. 1 is true. only No. 2 is true. both No. 1 and No. 2 are true.
A flexible sealing element subject to motion is a:
compound. packing. gasket.
Which instruments are connected to an aircraft's pitot-static system? 1. Vertical speed indicator. 2. Cabin altimeter. 3. Altimeter. 4. Cabin rate-of-change indicator. 5. Airspeed indicator.
1, 2, 3, 4, and 5. 1, 2, and 4. 1, 3, and 5.
Lockout deboosters are primarily pressure reducing valves that:
allow full debooster piston travel without fluid from the high pressure side entering the low pressure chamber. cannot allow full debooster piston travel without fluid from the high pressure side entering the low pressure chamber. must be bled separately after brake bleeding has been completed.
Which instruments are connected to an aircraft's static pressure system only? 1. Vertical speed indicator. 2. Cabin altimeter. 3. Altimeter. 4. Cabin rate-of-change indicator. 5. Airspeed indicator.
1 and 3. 2, 4, and 5. 2 and 4.
A DME antenna should be located in a position on the aircraft that will:
not be blanked by the wing when the aircraft is banked. permit interruptions in DME operation. eliminate the possibility of the DME locking on a station.
Filing or grinding a weld bead:
may be performed to achieve a smoother surface. reduces the strength of the joint. may be necessary to avoid adding excess weight or to achieve uniform material thickness.