mer fly Flashcards
Which four forces acts on an airplane to make it airborne?
Lift, thrust, weight and drag
Can you explain lift?
While in flight the airplane is supported by lift. Lift is the force acting opposite of gravity and is generated whenever air flows smoothly over and under the wings. As relativeair flows over and under the wing, the air that flows over the wing, as speed increases will loose pressure, but the relative air on the bottom side of the wing, will experience more pressure, witch will force the wings up and create an upward force. Low pressure on top of the airfoil and high pressure on the bottom of the airfoil is creating lift.
Witch force is caused by gravity and acts to pull the airplane towards the ground?
Weight
What is the force that opposes lift?
drag
What is the two things that is important to create lift?
relative wind and shape of the airfoil
Explane Bernoullis principle
As velocity of a moving fluid increases, the pressure within that fluid decreases.
(more pressure)——-less pressure-faster movement
What is the angle of attack?
Its the angle at which the wing Is slanted toward the airflow. Generally increasing at the angle of attack increases the lift. This is why an airplanes nose is pointing upwards in a climb.
what can happen at high angles of attack?
When the air on top of the airfoil has to travel a further way it can become turbulent. The air no longer flows along the top of the wing, but starts to leave its path and circulate upwards, witch makes the air on top even lighter(even less pressure) since the air no longer is close on the airfoil. The air on the bottom of the wing will hit the airfoil harder and cause more pressure, since it’s so difficult to get around to the other side. This can cause the plane to stall. Looses a lot of lift all at once.
Can you mention 5 types of wind in aviation?
propellar wash, relative wind, headwind, tailwind and wind caused by the thrust of the plane
witch wind directly opposes the direction the airplane is traveling?
relative wind
What is the wing of an airplane called?
an airfoil
For every action there is an equal an opposite reaction.
Newtonts 3. law
What is stalling?
When an airplane has a rapid loss of lift. When we increase the angle of attack too much, air doesn’t want to flow around the surface og the wing anymore. The air on top of the wing starts to get separated from the upper part of the wing. This means we don’t have good laminar airflow anymore. If you continue to increase the angle of attack even more, the wing will no longer be able to support the weight of the aircraft. When this happens, we get a rapid loss of lift. This rapid loss of lift, is what we call a stall.
laminar airflow?
as air flows above and below the wing, it does so in very thin layers. (Definition of laminar airflow is in fact thin horizontal layers)
When the air on top of the wing starts to get separated from the upper part of the wing. What is a word for this?
Boundry layer separation
What is the critical angle of attack?
Right before an airplane stall, it reaches a point where the corde line on the airfoil is at its greatest angle with the relative wind. If this angle increases at all at this point, the aircraft will stall. This angle of attack, is what we call critical angle of attack.
When you exceed the wings critical angle of attack the airplane will….
stall
How to fix an airplane in stall?
first, reduce the angle of attack.(pitch down or revise some of that backtick on the yoke.)
What is an aggravated stall?
Spin
What is spin?
When an airplane stalls, it’s possible for one wing to stall more than the other. This is called an aggravated stall. Yaw is introduced and causes a downward corkscrew path
When the vertical aksis of the aircraft is not aligned with the direction of travel, what is that called?
side slip
What is PARE?
Spin recovery procedure
What does the P in spin recovery procedure stand for?
Power- idle
What does the A in spin recovery procedure stand for?
Alerons and elevator- neutral
What does the R in spin recovery procedure stand for?
Ruddler- opposite(until the spinning stops)
What does the E in spin recovery procedure stand for?
Elevator up(to recover level flight)
In a spin, are both wings stalled?
YES
Which three axis is the pilot able to use to control the airplane in flight?
Lateral axis(pitch axis), longitudinal axis(roll axis) and vertical axis(yaw axis)
What is the point on the airplane where you can hang the airplane from a string and it would balance perfectly?
The centre of gravity. Its normally where the centre of movement of all three axis.
What Is stability
The ability an aircraft has to correct for disturbances in its equilibrium and return to its original flight plan. for eks. if you are pushed up by turbulence, a stable airplane will be able to pitch back down to its original flight path.
Why are fighter jets less stable aircraft?
because they are designed to be more maneuverable
What is the two types of stability that affects our three axis?
Static and dynamic stability
What is negative static stability?
When the airplane would continue to pitch beyond set degree
What is neutral static stability?
When the airplane continues in the same altitude as you pitched for
What is positive static stability?
If you pitch your airplane up a few degrees, and the airplane just descends back down
What is the airplanes response to an upset in the equilibrium over time called?
Dynamic stability
Some ways we can get longitudinal stability…
Some airplanes are designed so that the outer tip of the wing is higher that the wing root, this is called dihedral.
When the airplane has high wings, any time the aircraft rolls, the weight of the aircraft acts on the pendulum and swings it back to level flight, that’s keel effect
When we put a vertical fin on the tail of the aircraft, which acts like a weather vane. Anytime the vertical fin is not aligned with the relative wind. The relative wind will push the tail back until it alignes itself. What is this kind of stability called?
directional stability
What happens when you put too much weight behind in a plane the centre of gravity?
Yoou move the centre of gravity behind the centre of lift witch makes the plane less controllable, witch makes it less stable
What happens to the planes contorllability when you increase the angle og attack at low airspeeds?
The controllability and stability decreases. The centre of gravity is moved and the tail can’t produce enough downward force to keep the airplane stable
Anytime the engine is moving the propeller, air will flow over the surface of the airplanes control surfaces, what is that called
slip stream
Why is airspeed so imprtant to the airplanes controllability?
because every control surface needs relative wind to control the aircraft. The amount of relative wind depends mostly on the airplanes speed
What part of the airplane can increase lift, increase drag and make us able to land at slower airspeeds?
the flaps
When can it be beneficial to land with less flaps?
when you have gust crosswinds
What is the four common types of flaps?
plane flap(most basic type of flap), split flap(deflected from the lower surface of the airfoil), slotted flap(most common flap), flower flap(is a type of slotted flap. its designed to increase the surface area of the wing)
What do we use when we want to roll the airplane?
ailerons, with the yoke rotation left or right
What happens to the aileron that has been lowered by the yoke?
it creates more lift on that side
What is the name of the thing that happens when you are in straight level flight and produce lift, which result the airplane going up or down?
vertical lift
What is horizontal component of lift?
it is what makes our airplane turn. When we roll our airplane one direction or the other, not all the lift will be vertical anymore, some of the lift will move laterally.
Adverse yaw
Is when we roll or bank the airplane, the lowered aileron will produce more lift and more drag. Which means the nose of the airplane will be forced to point away from the direction of travel
How to correct adverse yaw
“Step on the ball”
An object in motion, will continue in motion until acted on by an outside force
Newtond 1. law
What’s the centrifugal force?
When we change the airplanes direction of travel by adding horizontal lift, we are creating that force. Our airplane wants to continue straight ahead and that’s the centrifugal force we have to overcome
What do we get when we combine the centrifugal force and weight?
We get load
What happens when we increase our bank angle?
The higher bank angle- the higher load
What do we measure load factor by?
g- forces (the force of gravity multiplied)
what is equal to 3 g´s?
the weight of our airplane times 3
what is g limitations
its how much the wings can handle of load factor
what happens with too much g ´s
wing damage
What is the easiest way to exceed the planes g limitations?
by exceeding the planes speed limitations
What happens when you multiply the weight and the load?
you get the total load
what happens at higher load?
higher stall speed
what does v- speeds stand for?
velocity (indicated airspeed)
Mention tre other types of airspeed except for v- speed…
calibrated airspeed, true airspeed and ground speed
What is the two climbing airspeeds?
Vx and Vy
What kind of climb airspeed do you want to pitch for if you want to clear an obstacle on the ground in your climb? (The highest altitude in the shores amount of distance)
Vx
What kind of climb airspeed do you want to pitch for if you want to climb in altitude as fast as possible? (Normally when you don’t need to clear for an obstacle)
Vy
The fastes airspeed you can fly without causing structural damage, what is this speed called?
Va
What kind of airspeed is Vfe?
The maximum speed with the flaps extended
What is Vno?
Normal operating speed
What is Vlo
maximum speed for extending and retracting the landing gear “landing gear lowered”
What is Vle
Maximum speed after the gear has been extended “landing gear extended”
What ar the two types og drag of an aircraft in flight?
induced drag and parasite drag
Which drag increases as airspeed increases?
parasite drag
which drag decreases as airspeed increases?
induced drag
What is the speed called that gives us the least amount of drag for the amount of lift the aircraft is producing?
LD max
Which climb airspeed is close to LD max?
Vy
What is the technical explanation of the throttle?
The throttle controls the amount of air entering the engine. Push it in to go faster, drag it out to go slower
When you are flying at a constant altitude, not going up or down, what is that called?
level flight
What is the airplanes attitude indicator?
artificial horizon, that showes the airplanes pitch and bank in relation to the horizon
What is the altimeter?
Shows the aircrafts height above mean sea level (MSL)
What is the vertical speed indicator?
it showes the airplanes rate in feet per minute the plane is going up or down. For most airplanes, a comfortable rate of climb of decent is between 500 and 1000 feet per minute.
What is a tachometer?
it showes how much power the engine is producing
What is AGL
Among ground level. The distance between the airplane and the ground. This is estimated by the MSL minus the estimated ground height
knots
nautical miles an hour
What does VFR stand for?
Visual flight rules. The pilot flies the plane in referance to the outside horizon. “Fair weather flying”
What is IFR?
Instrument flight rules. Requires a lot of additional procedures and air traffic control communications. This gives pilots the opportunity to fly in bad weather conditions.
What is IMC?
Instrumental Meterological conditions. This referring to low visibility or flying within coulds. This is only done when following IFR rules
What is the four w´s of communications?
who you are calling, who you are, where you are and what you want
