Army aircrafts Flashcards
(98 cards)
1
Q
What are some types of aviation missions you may do?
A
- Combat Operations: Close air support, air assault, reconnaissance.
- Humanitarian Operations: Disaster relief, search and rescue.
- Logistics and Transport: Cargo delivery, troop transport.
2
Q
Describe the 4 helicopters capabilities and roles.
A
- UH-60 Black Hawk: Utility, medevac, and assault.
- AH-64 Apache: Attack helicopter with advanced targeting systems.
- CH-47 Chinook: Heavy-lift for cargo and troops.
- LUH-72 Lakota: Light utility and domestic operations.
3
Q
Why do pilots like the CH-47?
A
Pilot Sentiment:
- Highly valued for its unparalleled heavy-lift capability and stability in difficult conditions.
Why Pilots Like It:
- Exceptional payload capacity (26,000 lbs external).
- Dual-rotor design offers enhanced stability in mountainous and adverse weather conditions.
- Used in a wide range of missions, from troop and cargo transport to humanitarian aid.
Best For:
- Heavy-lift missions, especially in challenging environments.
4
Q
Why do pilots like the LUH-72?
A
Pilot Sentiment:
- Generally appreciated for its reliability and simplicity, but not seen as a top choice for high-intensity combat.
Why Pilots Like It:
- Ease of operation and maintenance.
- Modern glass cockpit with advanced avionics.
- Effective for training, search and rescue, and non-combat roles.
Best For:
- Non-combat utility, training, and homeland security missions.
5
Q
Why do pilots like the AH-64?
A
Pilot Sentiment:
- Often considered the most thrilling to fly due to its advanced weapon systems and combat focus.
Why Pilots Like It:
- Highly effective for close air support and anti-armor missions.
- Advanced targeting systems like the Longbow radar give pilots a tactical edge.
- Renowned for survivability and lethality in high-threat environments.
Best For:
- Offensive operations and combat missions.
6
Q
Why do pilots like the UH-60?
A
Pilot Sentiment:
- Frequently described as the most versatile and balanced aircraft in the lineup.
Why Pilots Like It:
- Multi-mission flexibility, excelling in troop transport, medevac, and combat support.
- Robust design with high survivability.
- Pilots appreciate its balance of speed, agility, and payload capacity.
**Best For: **
- General-purpose utility, medevac, and tactical support.
7
Q
What are some UH-60 performance specs?
A
- Maximum Speed: 159 knots
- Cruising Speed: 150 knots
- Range: 320 nautical miles
- Service Ceiling: 19,000 feet
8
Q
What is the UH-60 crew and capacity?
A
- Crew: 2 (pilot and co-pilot) plus 2 crew chiefs/gunners.
- Passengers: Up to 11 fully equipped troops or 6 stretchers in MEDEVAC configuration.
9
Q
What are some LUH-72 performance specs?
A
- Maximum Speed: 145 knots
- Cruising Speed: 133 knots
- Range: 370 nautical miles
- Service Ceiling: 18,000 feet
10
Q
What are some LUH-72 power plant specs?
A
- Engines: Two Safran Arriel 1E2 turboshaft engines.
- Engine Power: 738 shaft horsepower per engine.
11
Q
What is the LUH-72 crew and capacity?
A
- Crew: 2 (pilot and co-pilot).
- Passengers: Up to 6 troops or 2 stretchers plus medical attendants.
12
Q
What are some UH-60 power plant specs?
A
- Engines: Two General Electric T700-GE-701D turboshaft engines.
- Engine Power: 1,940 shaft horsepower per engine.
13
Q
What are some CH-47 performance specs?
A
- Maximum Speed: 170 knots
- Cruising Speed: 140 knots
- Range: 400 nautical miles
- Service Ceiling: 20,000 feet
14
Q
What is the CH-47 payload capacity?
A
- Internal: Up to 24,000 pounds
- External (Sling Load): Up to 26,000 pounds
15
Q
What is the CH-47 crew and capacity?
A
- Crew: 3 (pilot, co-pilot, and flight engineer/crew chief).
- Passengers: Up to 33 troops or 24 stretcher patients plus medical attendants.
16
Q
What are some CH-47 power plant specs?
A
- Engines: Two Honeywell T55-GA-714A turboshaft engines.
- Engine Power: 4,733 shaft horsepower per engine.
17
Q
Describe the components of the helicopter structure.
A
- Fuselage
- Mast
- Engine
- Main rotor
- Second rotor
18
Q
What is the fuselage?
A
Body of the craft
19
Q
What is a mast?
A
Cylindrical metal shaft that protrudes upward out of the fuselage.
20
Q
What does the engine of the craft do?
A
Drives power upward through the mast to the rotor blades, which are controlled by the pilot.
21
Q
What is the main rotor used for?
A
To generate lift and thrust
22
Q
How is thrust from the main rotor balanced?
A
By a second rotor. (Usually a tail rotor)
23
Q
What is a tail rotor intended for?
A
To account for the effects of torque.
24
Q
What direction is it conventional for rotors in the USA, UK, and Germany to turn?
A
Main rotor rotates counter clockwise.
25
What are some advantages of rotorcraft?
1. Takeoff vertically
2. Hover
3. TOL in places planes can't
4. Perform tasks such as drop cargo/troops in challenging conditions.
26
What are the helicopter types?
- Single main rotor helicopters
- Tandem rotor helicopters
- Coaxial rotor helicopters
27
What is the most common design for a helicopter?
Single main rotor helicopters
28
Describe the single main rotor helicopter.
- Single main rotor generating power with a secondary rotor such as a tail rotor
- Tail rotor is used to offset the effects of torque
29
What's one disadvantage of the single main rotor helicopter design?
Some power is used for countering torque, rather than being used solely for lift.
30
Describe the tandem rotor helicopter.
- Has a front and rear main rotating blade
- Each set of blades rotates counter to the other, meaning torque is automatically offset
- No need for a tail rotor to deal with torque
- Because of this, all of the power from the engine can be used for lift.
- These are some of the fastest and most powerful in existence
31
Describe the coaxial rotor helicopter.
- Two sets of blades above and beneath each other
- Mounted to the same mast
- Rotates in opposite directions to each other
- This has the advantage of reducing payload and allowing for greater cargo/passenger capacity.
32
What is thrust created by?
The engine(s)
33
How is thrust transferred into motion?
Via the mast and rotors
34
Define drag.
A force which acts against thrust.
35
What causes drag?
The shape and size of the aircraft disrupting the flow of air as it travels.
36
What are the types of drag that impact helicopters?
1. Profile drag
- Form drag
- Skin friction drag
2. Induced drag
3. Parasite drag
4. Total drag
37
How is profile drag created?
Caused by the frictional resistance of helicopter blades passing through the air.
38
Describe the two components of profile drag.
Form: Increases as the speed of the helicopter increases.
Skin: Caused by microscopic roughness of the helicopter blades.
*Any roughness on the surface causes air to become trapped and drag to increase.*
39
How is induced drag created?
- Caused by airflow circulation around the blades creating vortices
- This type of drag increases when the helicopter is flying at lower speeds and decreases when it is flying at higher speeds.
- During low speed flight, induced drag is the main cause of drag.
40
How is parasite drag created?
- By the helicopter components that are external to the fuselage
- EX: Landing gear, cowlings, and doors can all create parasite drag.
- This drag slows down the speed of a helicopter by opposing thrust.
41
Define total drag.
The sum total of the profile, induced and parasite drag acting upon the helicopter at any given time.
42
What are some benefits of total drag being at its lowest?
- Maximum endurance
- Best rate of climb
- Minimum rate of descent in autorotation.
43
Define weight.
- Force which results from the combines mass of a helicopter being acted upon by gravity.
- It is a downward force which acts through the center of gravity of the helicopter.
44
Define lift.
The upward force created by the spinning of the helicopter blades allowing air to pass over them.
45
Define AOA (angle of attack).
A description of the angle at which the helicopter blade's direction of movement is relative to the air.
46
What can impact the AOA?
- Sometimes manipulated by the pilot, by moving the cyclic and collective
- Also impacted by factors outside the control of the pilot, such as blade flapping and flexing and turbulent conditions.
47
What are the 3 scientific principles that apply to helicopters.
1. Bernoulli's principle
2. Venturi flow
3. Newton's third law of motion
48
What are the 4 main flight controls?
1. Cyclic
2. Pedals
3. Collective
4. Throttle
49
What does a cyclic resemble?
A joystick.
50
What does moving the cyclic do?
Allows the pilot to alter the pitch angle of the main rotor blades, which causes thrust in a particular direction.
51
Where is the collective located and what does it do?
- Located to the left side of the pilot's feet and serves the purpose of simultaneously moving the pitch angle of the main blades.
- This impacts upon the total level of lift or thrust.
- As a result, the collective is used to increase or decrease altitude or airspeed.
52
Where are anti-torque pedals located?
At the pilots feet.
53
What do the anti-torque pedals do?
- Adjust the pitch of the tail rotor, altering the amount of thrust produced.
- Changes the direction of the nose of the helicopter.
54
What does the throttle control usually resemble?
Motorcycle-style rotating grip.
55
What's the difference in throttles for dual engine aircraft?
There is a separate throttle for each engine, usually taking form of a lever.
56
What are the 4 basic flight maneuvers?
1. Straight and level
2. Turns
3. Climbs and descents
4. Hovering
57
What is straight and level flight?
- When a helicopter moves at a steady altitude and heading.
58
How is straight and level flight achieved?
- Tilting the nose forward, increasing the speed at which the helicopter moves.
- The lower the nose, the more power required.
59
How are turns achieved?
- By pushing the cyclic in the desired turning direction.
- This causes the rotor to tilt.
- The anti-torque and throttle controls are used in conjunction to ensure the altitude is maintained during the turn and the process is smooth.
60
What is hovering?
When helicopter moves as minimally as possible at a constant heading and altitude over a reference point.
61
How are climbs and descents achieved?
- Through manipulation of the collective.
- Moving the collective manipulates the amount of lift, causing the helicopter to rise or fall as the pilot desires.
62
How is hovering achieved?
By the pilot subtly correcting variations in motion
63
What is the key to hovering?
Make very small corrective motions which are ceased before the helicopter begins to move.
64
What are the 3 types of helicopter taxi?
1. Hover taxi
2. Air taxi
3. Ground taxi
65
How high does hover taxiing occur?
25 ft or less above ground level.
66
How high does air taxiing occur?
100 ft or less and requires the pilot to avoid flying over people, vehicles, and other aircraft.
67
What are the types of army aircraft?
- Sikorsky UH-60 Blackhawk
- Boeing CH-47 Chinook
- Boeing AH-64 Apache
- Eurocopter UH-72 Lakota
68
UH-60 weapons.
- M240 machine
- M134 Minions
- Hydra-70 rockets
- VOLCANO mine field dispersal system.
69
AH-64 weapons.
- 1200 round M230 chain gun.
- Hydra-70 air to ground rockets
- AGM-114 hellfire missiles.
70
What all governs the speed of the air flowing across the blades?
1. Shape of the revolving blade
2. Air velocity of the helicopter
3. Position of the airfoil in the plane
71
What is unique about the shape of a helicopter blade?
- It is made in such a way that for every revolution, the longitudinal velocity vector is sometimes with the helicopter's forward velocity and sometimes opposite to it.
- EX: A regular helicopter blade that revolves counterclockwise generates a maximum airflow velocity at its 3 o'clock position and a minimum at its 9 o'clock position.
72
What is autorotation?
- A situation during flight of an airborne helicopter, when air lift in generated only by the air flowing across its blades.
- In case of a failure, this feature allows pilots to land the helicopter without crashing it.
- On failure, the freewheeling unit comes in effect to disconnect power to the mains rotor.
- As a result, the blades spin freely, causing autorotation of the helicopter by the air present around them.
73
What is freewheeling?
- Automatically disengages the engine from the main rotor when RPM is less than main rotor rpm.
- This allows the main rotor and tail rotor to continue turning at normal in- flight speeds
- Mandatory feature for autorotation in helicopters according to aviation standards, and all helicopter pilots are trained to use this feature in case of emergencies to avoid crashes.
74
How is autorotation during. helicopters forward motion minimized?
- By reducing the driven region on the retreating blade.
- During forward motion, the rotor disc experiences lift by upward flowing air on the driven, driving and stall region along the length of the blade, and on the retreating side of the blades (in counter clockwise motion, the blades move from the nose to the tail).
- The driven region expands on the advancing side due to the lower AOA, while the stall region expands on the retreating side.
- The driven region on the retreating side is also reduced by reversed airflow.
75
True or False:
The relative wind is slower near the root of the blade than on the tip.
True. This results in different aerodynamic forces across the surface of the blade in the driven, driving, and stall regions.
76
What effect does blade twist have one the AOA in the driven region?
- Makes the AOA in the driven region smaller than the AOA in the driving region.
- This causes deceleration of the rotor, as the lift produced by hovering ins neutralized by air drag, due to total aerodynamic force (TAF).
77
What 3 things influence the size of the driving region?
1. Number of RPM
2. Blade pitch
3. Rate of descent
*Therefore, the driving region can be altered by changing any of these features.*
- This generates an acceleration force responsible for thrust.
78
Describe the stall region of a hovering helicopter.
- Is the circular area formed by the revolving of the first quarter of the blade from the root of the rotor.
- The AOA during hovering is maximized, creating drag and subsequently, reducing blade rotation.
79
What causes blade flapping?
Greater airlift during hovering.
80
In regards to blade flapping, describe the blade angles design.
- It is designed in such a way that during hovering, air lift is balanced by the centrifugal forces of the spinning wheel.
- The blades move faster to balance the lift that is increased by airflow, or spins of the blades, during autorotation while hovering.
81
What is a blade span?
The distance between the tip of the blade and the drive shaft on the rotor it is attached to.
82
What is blade twist?
A design feature of a helicopter blade to distribute air lift evenly throughout the surface of the airfoil.
83
How is blade twist attained?
By generating greater pitch angles toward the blade root. one low rotational velocities, and vice versa.
84
When does dissymmetry of lift occur?
During take off.
85
What causes dissymmetry of lift?
- Caused by the difference in amounts of force experienced by advancing and retreating blades of the helicopter on either side of the rotor disc.
* Due to forward motion, the wind speed on the advancing is more prone to create unbalance, which eventually causes the helicopter to crash*
86
How is dissymmetry countered ?
By blade flapping, which. its when the retreating blade flaps down and the advancing blades flaps up, and vice versa.
87
What is setting with power?
- That state of a helicopter's flight when it descends vertically downward, at about a rate of 5 ft per second and low forward speeds.
- It is a state of stall when, even though the main rotor system is using 20% up to 100% of the power generated by the engine, the down flow produced by the spinning blades is uses to overcome the up flow caused by drastic descent, leading to turbulence.
88
What is the vortex ring state?
Another name for settling with power. Since maximum power is used by the rotor, minimal or no power is available for the pilot to stop the descent.
89
What can be classified into scalar and vectors?
All physical quantities, such as length, time, mass, speed, velocity, and force.
90
What is a scalar?
- Physical quantities that have only a magnitude or size.
- EX: distances between two points and mass of a body.
91
What’s another name for Newtons 1st law of motion?
Law of inertia
92
What is Newton’s 1st law of motion?
- The law that states that “Until acted on by an external force, an object’s velocity will remain constant.”
93
What is center of gravity?
That point of a body through which the weight of the body acts.
94
Define torque.
- The product of force and moment arm.
- It is a vector quantity with the SI unit of Nm
- Also called a moment of a force
- It causes a rotation of a body about a point called the pivot or the fulcrum
95
What are the 3 types of levers?
1. First class levers
2. Second class levers
3. Third class levers
96
What are the 4 tracks you can go into?
1. Standardization
2. Maintenance
3. Instructor
4. Safety
97
What is AR 95-1?
Aviation flight regulations
98
