10 Most important and commonly used Aircraft Terminologies

Every aviation student or enthusiast should know:

✈️ 10 Important Aircraft Terminologies

MTOW (Maximum Takeoff Weight)

• The maximum weight at which an aircraft is certified to take off safely.

MLW (Maximum Landing Weight)

• The maximum weight at which an aircraft can safely land without structural damage.

MZFW (Maximum Zero Fuel Weight)

• The maximum permissible weight of the aircraft without fuel (includes payload + crew + equipment).

CG (Center of Gravity)

• The point where the aircraft’s total weight is balanced, critical for stability and control.

Thrust-to-Weight Ratio

• A measure of engine performance; compares thrust produced by engines to aircraft weight.

Service Ceiling

• The maximum altitude an aircraft can reach while maintaining a specified rate of climb.

Range

• The maximum distance an aircraft can fly on a full fuel load under specified conditions.

ETA (Estimated Time of Arrival)

• The predicted time an aircraft will arrive at its destination.

V-Speeds (Velocity Speeds)

• Standard airspeeds important for operation, e.g.:
• V1 = Decision speed (abort/takeoff decision).
• VR = Rotation speed (nose lifts off).
• V2 = Takeoff safety speed.

Flight Envelope

• The limits of an aircraft’s speed, altitude, and maneuverability within which it can operate safely.

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What is Aircraft Basic System and types of Aircraft Systems with Definitions

 Aircraft Basic Systems

Aircraft systems are essential components that ensure the safe operation, performance, and control of the aircraft. These systems support various functions such as propulsion, navigation, communication, and passenger safety.

Types of Aircraft Systems with Definitions:

1. Electrical System

• Definition: Provides electrical power to instruments, lights, avionics, and other systems.
• Components: Batteries, generators, alternators, wiring, circuit breakers.

2. Hydraulic System

• Definition: Uses pressurized fluid to operate components like landing gear, flaps, and brakes.
• Components: Hydraulic pumps, reservoirs, actuators, valves.

3. Pneumatic System

• Definition: Uses compressed air for operations such as air conditioning, pressurization, and de-icing.
• Components: Compressors, regulators, ducting, valves.

4. Fuel System

• Definition: Supplies and regulates fuel to the engines.
• Components: Fuel tanks, pumps, valves, filters, fuel lines.

5. Propulsion System

• Definition: Provides the thrust necessary for flight using engines (jet or propeller).
• Components: Engines, propellers, thrust reversers.

6. Avionics System

• Definition: Includes all electronic systems used for communication, navigation, and monitoring.
• Components: Radios, GPS, transponders, autopilot, radar.

7. Environmental Control System (ECS)

• Definition: Maintains a comfortable cabin environment including temperature, pressure, and air quality.
• Components: Air conditioning units, pressurization valves, filters.

8. Landing Gear System

• Definition: Supports the aircraft during landing, take-off, and while on the ground.
• Components: Wheels, struts, brakes, steering systems, retracting mechanisms.

9. Flight Control System

• Definition: Controls the movement and attitude of the aircraft.
• Types:
• Primary Controls (e.g., ailerons, elevators, rudder)
• Secondary Controls (e.g., flaps, spoilers, trim tabs)

10. Ice and Rain Protection System

• Definition: Prevents ice formation and clears rain from critical surfaces.
• Methods: Thermal, pneumatic, chemical, mechanical systems.

11. Fire Protection System

• Definition: Detects and extinguishes fires in engines and other areas.
• Components: Fire detectors, extinguishers, warning systems.

12. Oxygen System

• Definition: Provides supplemental oxygen to crew and passengers at high altitudes.
• Components: Oxygen masks, cylinders, regulators.

 

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M-12 Final Practice Test-2 ( Helicopter Aerodynamic 116 Questions 145 Mints)

Module - 12 (Helicopter Aerodynamic)

Final Practice Exam Test

  

 

1. Lift generated by a blade is proportional to the?
   1.   blade speed and angle of attack
   2.   relative airflow and the pitch
   3.   relative airflow and the angle of attack
2. Phase lag is due to the blades ?
   1.   weight
   2.   rotational velocity
   3.   inertia
3. A helicopter hovering near a tall building will ?
   1.   drift towards it
   2.   be unaffected by it
   3.   drift away from it
4. When the cyclic stick is eased forward in the hover position ?
   1.   altitude is increased
   2.   vertical lift is reduced
   3.   forward thrust is decreased
5. Static stability of a helicopter is ?
   1.   the stability of the helicopter when
      hovering
   2.   the tendency to oscillate until the neutral is achieved
   3.   the tendency move back toward neutral after disturbance
6. During forward flight the advancing blade will?
   1.   lag
   2.   flap down
   3.   flap up
7. What principle does the delta 3 hinge use?
   1.   Triangular pitch change lever
   2.   Offset hinges
   3.   Flapping actuators
8. Solidity of the rotor is the ratio of the ?
   1.   all up weight to disc area
   2.   all up weight to blade area
   3.   blade area to disc area
9. What is a controlling factor of turbulence and skin friction?
   1.   Countersunk rivets used on skin exterior
   2.   Fineness ratio
   3.   Aspect ratio
10. Helicopters in forward flight are usually ?
    1.   longitudinally stable
    2.   laterally stable
    3.   directionally stable
11. The tropopause exists at about ?
    1.   36,000 ft
    2.   18,000 ft
    3.   30,000 ft
12. The HUMS receives signals from ?
    
    1.   transponders
    2.   transformers
    3.   transducers
13. What causes lateral vibration ?
    
    1.   Tail drive shaft misalignment
    2.   Main rotor head
    3.   Loose load/vibration absorber
14. A series actuator in a helicopter autopilot system has ?
    1.   50% authority
    2.   10% authority
    3.   full authority
15. The tail rotor is subject to ?
    
    1.   positive torque
    2.   negative torque
    3.   both positive and negative torque
16. What is the difference between transient and static droop ?
    
    1.   Centrifugal latches
    2.   Over-swing
    3.   Under-swing
17. The ability of the blade to move up and down is ?
    1.   feathering
    2.   flapping
    3.   dragging
18. When raising the collective lever ?
    
    1.   the pitch is increased on all blades
    2.   the angle of attack is decreased on the retreating blade
    3.   the pitch is decreased on all blades
19. The throttle hand grip is located on the ?
    
    1.   throttle box
    2.   cyclic stick
    3.   collective lever
20. Pitch trimming in autopilot is initiated by ?
    
    1.   continued pitch input
    2.   pitch of aircraft in cruise
    3.   C of G movement
21. Aircraft emergency escape slides are usually pressurised with ?
    
    1.   Oxygen
    2.   Helium
    3.   CO2
22. Where the aircraft passenger seating capacity exceeds 149 but less than 200 then ?
    
    1.   1 megaphone is required
    2.   2 megaphones are required
    3.   3 megaphones are required
23. The minimum vertical projected separation between seat rows is ?
    
    1.   7 inches
    2.   5 inches
    3.   3 inches
24. Engine wing fire bottles should be charged with nitrogen at 15 °C to ?
    
    1.   1250 psi
    2.   600 psi
    3.   1500 psi
25. A fire that can be put out by a crew member in a cargo bay is in a ?
    
    1.   class D compensation
    2.   class C compensation
    3.   class B compensation
26. A Systron-Donner fire detection system uses ?
    1.   helium gas
    2.   oxygen gas
    3.   nitrogen gas
27. The weight of an extinguisher is stamped ?
    1.   on bracket
    2.   on head fitting
    3.   on base of body
28. A fuel cross-feed valve is lubricated ?
    1.   by the fuel
    2.   by air
    3.   by internal cooling
29. Bladder type fuel tanks are secured by ?
    1.   bolts
    2.   contact adhesive
    3.   press type rivets
30. A constant delivery pump has its output varied with ?
    1.   gears
    2.   regulators
    3.   servo pressure
31. Prior to aluminium alloy bonding, we use ?
    
    1.   solvent etch
    2.   alkaline etch
    3.   acid etch
32. A radome is protected from static electricity build-up by ?
    1.   bonding strips
    2.   special conductive grease
    3.   conductive paint
33. What is the ideal storage temperature for windscreen panels?
    1.   50 °F to 70 °F
    2.   50 °C to 70 °C
    3.   30 °C to 50 °C
34. Which anti-corrosive treatment is found on alloy steels ?
    1.   Zinc plating
    2.   Cadmium plating
    3.   Nickel plating
35. Which of the following is an example of a failsafe structure ?
    1.   Spar
    2.   Longeron
    3.   Stringer
36. A material commonly used for bulkhead sealing is ?
    1.   PTFE
    2.   soft rubber
    3.   aluminium
37. The helicopter's normal axis is ?
    1.   through the centre of gravity, perpendicular to longitudinal and lateral axis
    2.   through the centre of gravity, between
       the main and tail rotor
    3.   hrough the centre of lift, perpendicular
       to air flow
38. The main forces on an helicopter structure are ?
    1.   tension, compression, twisting and shear
    2.   tension, compression, torsion and strain
    3.   tension, compression, torsion and shear
39. What governs the ultimate fatigue life of an helicopter ?
    1.   Pressure Cycles
    2.   Flying Hours
    3.   Landings
40. A partition within the helicopter's structure is called a ?
    1.   bulkhead
    2.   cleat
    3.   frame
41. A member taking a compression load is called a ?
    1.   strut
    2.   cable
    3.   beam
42. If a colour is used to identify primary structure, it will be ?
    1.   green
    2.   yellow
    3.   red
43. Perspex is resistant to ?
    1.   Acetone
    2.   Paraffin
    3.   C.T.C
44. If an helicopter has alkaline batteries, the battery compartment drain pipes will be ?
    1.   aluminium alloy
    2.   plastic
    3.   stainless steel
45. Helicopter frames are constructed of ?
    1.   'U' section
    2.   'Z' section
    3.   'I' section
46. Buckling in a semi-monocoque structure is prevented by ?
    1.   bulkheads
    2.   longerons
    3.   stringers
47. A Fenestron tail rotor ?
    1.   has four blades
    2.   is a shrouded rotor
    3.   is a variable speed rotor
48. How much air is required for the Flight Deck ?
    1.   10 cubic feet/minute
    2.   10 lbs/minute
    3.   Whatever the captain sets
49. In a Bleed Air air-conditioning system, the warm air supply is provided by ?
    1.   the engine exhaust heat
    2.   the compressor of the gas turbine
       engine
    3.   the gas turbine exhaust
50. A water separator is located ?
    1.   upstream of the turbine
    2.   downstream of heat exchanger
    3.   downstream of turbine
51. Which of these barometric instruments uses a restrictor to compute its output ?
    1.   VSI
    2.   Machmeter
    3.   ASI
52. Track altitude in a radio altimeter system begins at ?
    1.   10000 ft radio alt
    2.   2500 ft radio alt
    3.   1000 ft radio alt
53. The runway heading is ?
    1.   QDR
    2.   QDM
    3.   QFU
54. The vacuum system gauge reads 5 inches of mercury, This is from ?
    1.   ambient and minus
    2.   zero and positive
    3.   zero and minus
55. For A helicopter certificated after 1997 and with RVSM, the maximum tolerance for the system would be ?
    1.   +/-500 feet for the system overall
    2.   +/-300 feet plus +/-50 feet for
       instrument errors
    3.   +/-200 feet plus +/-50 feet for instrument error
56. The HSI provides information on ?
    1.   VOR, ILS, plan, attitude
    2.   VOR, ILS, map, radar, attitude
    3.   VOR, plan, map, ILS, radar
57. When aligning an helicopter for a compass swing, the maximum allowable error is ?
    1.   1 degrees
    2.   5 degrees
    3.   3 degrees
58. Which pitot probe provides information to the captains instruments ?
    1.   Upper
    2.   Lower
    3.   Both
59. Which instrument shows Decision Height ?
    1.   ECAM
    2.   HIS
    3.   ADI
60. Compared to air driven gyros, the electric gyro runs. ?
    1.   faster
    2.   slower
    3.   same speed
61. The needle of a resolver is connected to?
    1.   two coils and a permanent magnet
    2.   two coils and an electromagnet
    3.   two coils only
62. Gyro rigidity is proportional to ?
    1.   mass, speed and radius of mass from
       spin axis
    2.   mass, and radius of mass from spin axis
    3.   mass and speed
63. A V.S.I. is connected to ?
    1.   vacuum
    2.   pitot pressure
    3.   static pressure
64. The millibar is a unit of ?
    1.   barometric pressure
    2.   pressure altitude
    3.   atmospheric temperature
65. A temperature of 59 °F is equivalent to ?
    1.   32 °C
    2.   14.69 °C
    3.   15 °C
66. Limit stops are fitted in an artificial horizon to ?
    1.   reduce gimbal nutation
    2.   prevent gimbal lock
    3.   limit the outer gimbal movement
67. Isogonal lines link places of ?
    1.   zero variation
    2.   equal variation
    3.   different variation
68. If True Airspeed is 470 knots, what is the Equivalent Air speed?
    1.   278 knots
    2.   550 knots
    3.   662 knots
69. If an altimeter millibar scale was set to 1 0 1 3.2 5 and the barometric pressure at that time was 1020, the altimeter should read?
    1.   positive altitude
    2.   zero feet
    3.   below zero feet (negative altitude)
70. To prevent corrosion at the terminals of a lead-acid battery ?
    1.   copper connectors are used
    2.   petroleum jelly may be applied to the connections
    3.   the connectors may be painted
71. Pressure may be expressed in ?
    1.   weight or mass
    2.   force per unit volume
    3.   force per unit area
72. One dot VOR deviation represents ?
    1.   2 miles
    2.   5 °
    3.   1 1/4 °
73. The fluid suitable for use in a Dead Weight Tester is?
    1.   castor-oil
    2.   kerosene
    3.   anti-freeze oil
74. The capsule in an altimeter responds to ?
    1.   differential pressure
    2.   absolute pressure
    3.   gauge pressure
75. How many axis does the helicopter autopilot control?
    1.   Three
    2.   Four
    3.   Two
76. Emergency frequency is ?
    1.   125.5 Hz
    2.   123.5 Hz
    3.   121.5 Hz
77. A radar altimeter in track mode is effective to ?
    1.   2000 ft
    2.   2500 ft
    3.   1000 ft
78. How do you clean seat belts ?
    1.   With MEK
    2.   With white spirit
    3.   With warm water with low alkalinity soap
79. A 'hyperbolic' system is ?
    1.   LORAN C
    2.   VOR
    3.   ILS
80. What is the reply frequency of an aircraft transponder ?
    1.   1090 MHz
    2.   1000 MHz
    3.   1030 MHz
81. What does the differential sensing coil sense ?
    1.   Power
    2.   Current
    3.   Volts
82. Where does the GCU gets its power?
    1.   Battery
    2.   RAT
    3.   PMG
83. Excessive commutator sparking can be caused by ?
    1.   brushes positioned on MNA
    2.   rotating field diode failure
    3.   weak spring tension
84. The ground interlock pins are numbered ?
    1.   A and B
    2.   C and N
    3.   E and F
85. Diodes are placed across a contactor to ?
    1.   prevent contact bounce
    2.   speed up operation by reducing back
       EMF
    3.   ensure smooth contactor operation
86. Oxygen purging is a process of ?
    1.   pressure testing the system
    2.   measuring the flow rate from the regulator
    3.   removing moisture from the system
87. On testing a generator it is found to require adjusting, where would you adjust it ?
    1.   By means of a remote trimmer
    2.   By means of a remote trimmer
    3.   On the GCU
88. The purpose of a synchronising bus bar is?
    1.   to allow monitoring and trimming from
       the flight deck
    2.   to enable two propeller systems to be
       synchronised
    3.   to monitor total current load
89. Battery charging procedures can be found in ATA ?
    1.   Chapter 24 Section 31
    2.   Chapter 24 Section 21
    3.   Chapter 31 Section 21
90. Zener diodes are for ?
    1.   voltage stabilisation
    2.   voltage regulation
    3.   rectification
91. In a generator system, a stability winding is used ?
    1.   to prevent voltage overshoot
    2.   in series with the field to prevent
       oscillations
    3.   to control output current
92. Specific Gravity in a lead acid battery should give an indication of ?
    1.   electrolyte temperature
    2.   electrolyte level
    3.   charge
93. A neutralising agent for sulphuric acid is ?
    1.   citric acid
    2.   borax powder
    3.   sodium bicarbonate
94. What is the purpose of the diode on a contactor ?
    1.   Prevent bounce
    2.   Prevent spikes
    3.   To prevent current going the wrong way
95. A P.M.G (Permanent Magnet Generator) is a small built in generator which ?
    1.   provides initial excitation
    2.   only rotates during starting
    3.   only rotates after starting
96. ILS marker beacon lights are ?
    1.   green, blue, amber
    2.   blue, white, green
    3.   blue, amber, white
97. A GPS satellite will come into view ?
    1.   10 ° above the horizon with respect to
       the viewer
    2.   20 ° above the horizon with respect to
       the viewer
    3.   15 ° above the horizon with respect to
       the viewer
98. CAT 2 RVR limit is ?
    1.   200 meters
    2.   400 meters
    3.   800 meters
99. What is primary radar ?
    1.   Radar that sends out pulse and receives reflected pulse
    2.   Radar that gives height and position
    3.   Land based
100. The components of an ILS are ?
     1.   a localizer and the marker beacons
     2.   a localizer, a glide slope and the marker beacons
     3.   a localizer and a glide slope
101. What channel of the autopilot does the glide slope control ?
     1.   Pitch
     2.   Roll
     3.   Yaw
102. The VOR system comprises ?
     1.   reference phase signal
     2.   variable phase signal
     3.   variable and reference phase signals
103. When an helicopter is heading due north (magnetic) towards a VOR station the reference and variable signals will be ?
     1.   180 ° out of phase
     2.   270 ° out of phase
     3.   150 ° out of phase
104. The Inertial Navigation System computes distance from acceleration by ?
     1.   a single integration
     2.   a differential followed by an integration
     3.   two successive integrations
105. The GPS satellite system consists of ?
     1.   20 satellites and 5 standby satellite
     2.   21 satellites and 3 standby satellites
     3.   24 satellites and 1 standby satellites
106. Windshield heating provides ?
     1.   thermal expansion for a tighter fit
     2.   impact resistance enhancement
     3.   increases strength to resist cabin
        pressure
107. The decision height light will illuminate when ?
     1.   the aircraft's indicated altitude is above decision height
     2.   the decision height is selected
     3.   the aircraft's indicated altitude is below decision height
108. On a flight management system, the database is updated every ?
     1.   2 Months
     2.   1 Months
     3.   3 Months
109. Upper and lower strobe lights are coloured ?
     1.   red
     2.   green
     3.   white
110. What is the arc of a landing light is ?
     1.   15 °
     2.   11 °
     3.   20 °
111. Tyre creep could be caused by ?
     1.   excessive wear
     2.   over pressure
     3.   under pressure
112. Ribbed tyres with marker tie bars may be worn to ?
     1.   the top of the tie bar
     2.   the base of the tie bar
     3.   1 mm from the rib base
113. When checking for alignment of a MLG, check ?
     1.   symmetry, twist, tracking
     2.   symmetry, splay, tracking
     3.   symmetry, tracking, camber
114. The purpose of the flutter plate in a shock absorber is to ?
     1.   separate the oil from the air
     2.   restrict the compression of the air
     3.   permit free flow of oil during compression and restriction of oil during extension
115. Air for anti-icing of the wings is obtained from ?
     1.   air conditioning ducting
     2.   engine compressors
     3.   a combustion heater
116. Rotor disc attitude is altered by ?
     1.   swash plate & spider assembly
     2.   ball & screw system
     3.   rotating block

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