Flashcards in Nelnet Army Aviation Information Test Deck (40):
A lighted heliport may be identified by
a green, yellow, and white rotating beacon
The primary purpose of the tail rotor system is to
counteract the torque effect of the main rotor
During a hover, a helicopter tends to drift in the direction of the tail rotor thrust. This movement is called
The upward bending of the rotor blades resulting from the combined forces of lift and centrifugal force is known as
In a helicopter, the center of gravity (CG) range is usually located
A short distance fore and aft of the main rotor mast
The lift differential that exists between the advancing main rotor blade and the retreating main rotor blade is known as
Dissymmetry of lift
Ground resonance is most likely to develop when
A series of shocks causes the rotor system to become unbalanced
The proper action to initiate a quick stop is to
Lower collective pitch and apply aft cyclic
Takeoff from a slope in a helicopter with skid-type landing gear is normally accomplished by
Bringing the helicopter to a level attitude before completely leaving the ground
The proper procedure for a slope landing in a helicopter with a skid-type landing gear is
When parallel to the slope, slowly lower the upslope skid to the ground prior to lowering the downslope skid
Density altitude refers to a theoretical air density that exists under standard conditions at a given altitude. Standard conditions at sea level are
29.92 in Hg (inches of mercury) and 15 degrees Celsius
A helicopter pilot should consider using a running takeoff
When gross weight or density altitude prevents a sustained hover at normal hovering altitude
Foot pedals in the helicopter cockpit enable the pilot to
Control torque effect
If the helicopter is moving forward, the advancing blade will be in the
Right half of the rotor disc
The method of control by which the pitch of all main rotor blades is varied equally and simultaneously is the
Collective pitch control
The combination of factors that will reduce helicopter performance the most is
High altitude, high temperature, and high humidity
The most favorable conditions for helicopter performance are the combination of
Low-density altitude, light gross weight, and moderate-to-strong winds
--> Relative Wind
Angle of Attack
During surface taxiing, the helicopter pilot should use the pedals to maintain heading and the cyclic to maintain
The thinner air of higher altitudes causes the airspeed indicator to read "too low." An indicated airspeed of 80mph at 5,000 feet is actually a true airspeed of approximately
How does blade rotation create lift?
Laminar flow of air molecules generates a low pressure area above the rotating airfoils relative to under.
How does raising the collective change the angle of attack (AOA) and center of pressure (CP)?
The relative wind to chord line angle increases, and the CP above the blade moves forward
Without changing your altimeter, your true altitude in flight will
Increase with increases in pressure
Changing an altimeter from 29.85 to 30.00 is what apparent change in elevation or altitude?
150 feet increase
Ground effect is best described as
Induced lift caused by decreases in drag due to ground disruption of airfoil upwash, downwash, and blade tip vortices
Assuming no-wind, describe the aerodynamic forces required for stationary hover
Thrust and lift act in the same vertical direction and are both equal to a combined weight and drag
What are the Newton laws of motion
- A body at rest will remain at rest and a body in motion will remain in motion
-Acceleration is a change in magnitude or direction of the velocity vector with respect to time
-For every action, there is an equal and opposite reaction
-The force required tor produce a change in motion is directly proportional to its mass and rate of change in velocity
What airfoil terminology defines the downward flow of air?
What changes rotational pitch of the rotor blades?
Cyclic pitch control
What is the function of foot pedals in a helicopter?
To move the aircraft about the vertical axis
What is an airspeed indicator (ASI) indication of a clogged static port?
ASI will indicate slower than actual speeds on climbs and faster on descents
During a forward autorotation, the inner 25 percent of blade region is referred to as the
Which of the following is NOT a factor for weight and balance calculations?
Tactical terrain flight at night up to a level of 25-feet-tall trees and obstacles is called what?
Nap-of-the-earth (NOE) flight
Which of the following is NOT a consideration when using NVGs?
Objects with poor reflective surfaces such as wires and suspension lines are easier to see
What is a Fenestron?
An anti-torque rotor that uses forced air through slots and rotating nozzle (protected tail rotor)
What is not an effect of ice build-up on your airfoil?
What chart uses a 1:500,000 scale?
Sectional aeronautical charts
What happens when you push forward on cyclic pitch in a two-bladed rotor system?
Gyroscopic precession exposed to differing blade AOA occurns 90 degrees from stick deflection