Principles Of Flight Flashcards
While an airplane is in the air, there are 4 forces acting upon it. Which are:
Lift, weight, thrust, and drag
What is lift?
Lift is the upward force created by the wi gs as the air flows around it
What is weight?
Weight is the downward force toward the center of the earth. Opposite of lift, which exists due to gravity.
What is thrust?
Thrust is the forward force, which is generally created by the aircraft propellers or turbine engines, which pulls or pushes the aircraft through the air.
What is drag?
Drag is the force acting in the direction opposite of thrust, which fundamentally limits the performance of the airplane
When an airplane is maintaining heading, altitude, and airspeed, it is said to be in what?
Straight-and-level unaccelerated flight
In unaccelerated flight _______
Lift equals weight, and thrust equals drag
In unaccelerated flight _______
Lift equals weight, and thrust equals drag
Airfoils
An airfoil is generally any surface that creates an aerodynamic force as a fluid.
Fluids are _______
Any substance that deforms under an applied stress
Liquids, gases, and plasma are all considered _______
Fluids
In addition to the wings, all the flight control surfaces, as well as the propeller, are considered _______
Airfoils
The aircraft’s fuselage is even an _______
airfoil, but it is not very good at producing lift.
The forward most point of the wing is called the _______. The aft most point is called the
Leading edge
Trailing edge
If we connect the leading edge and trailing edge with an imaginary line, this line would be called the _______
Chord line
As an airplane is moving through the air, the path that the airplane travels along is known as its _______
flight path
The airflow that flows around the airplane as it travels through the air is known as the _______
relative wind. The relative wind is parallel to but opposite of the aircraft’s flight path
The angle between the aircraft’s chord line and the relative wind is known as the _______
Angle of attack. The angle of attack is a major factor as to how much lift the wings generate
Newton’s 3 laws of motion:
- A body at rest remains at rest or in motion until acted upon by an outside force
- Force is equal to mass times acceleration
- For every action, there is an equal and opposite reaction
As the velocity of a fluid (in this case air) increases, _______
its internal pressure decreases
Imbalance in pressure is called a _______
Pressure gradient
Planform refers to _______
the shape of the wing when viewed from above
Camber is the _______
curvature of the wing
Camber is usually designed into an airfoil to increase _______
the maximum coefficient of lift. And thereby minimize the stall speed of the aircraft
The wings aspect ratio is the relationship between _______
the length and width of the wing. Generally, the higher the aspect ratio, the more efficient the generation of lift is.
The wing area is _______
the total surface area of the wings
High lift devices such as flaps are designed to _______
Increase lift and drag. Flaps allow the airplane to land at a fair steep descent angle without gaining any airspeed, and allows the airplane to touchdown at a much slower airspeed.
Flaps can be lowered in _______
steps, or more precisely in set degree amounts
Initially, the input of flaps will increase _______
lift with only a small drag increase. As flaps are extended further, usua,ly about the halfway point, lift increases slightly, and drag rapidly.
Weight is _______
the force of gravity pulling the aircraft back down to the earth
Throughout the flight, weight will slowly decrease _______
due to fuel powering the engine.
Thrust is the _______
forward acting force propelling the airplane through the air
In most general aviation airplanes, thrust is created by the _______
propellers, or in larger jets, the turbine engines
Similar to lift, thrust is generated from the same _______
principles as lift but in horizontal direction
Drag is _______
the force opposing thrust which limits the speed of an aircraft
There are two types of drag:
Parasite drag and induced drag
Parasite drag is _______
the direct result of air resistance as the airplane through the air
There are 3 types of parasite drag:
- Form drag
- Interference drag
- Skin friction drag
Form drag results from _______
the turbulence created as the air tries to flow around the aircraft
Interference drag occurs in ______
locations over the aircraft where different surfaces meet
Putting an object closer together will create up to _______. To minimize this, _______
- 200 percent more drag
- manufacturers will place smaller angular pieces at these locations
Skin friction drag is caused by _______. A good example of this are _______. Keeping the surfaces clean and waxed while also utilizing flush mount rivets will _______
- the rough imperfections of an airplane surface
- the rivets located on the airplane skin
- minimize the production of skin friction
As the airplanes speed increases, the amount of parasite drag will __________
also increase
While the wing is creating lift, behind the wing there is a _______. At the same time ______. As these vortices wrap around the wing _______. This in effect _______
- downwash of air
- The airflow around the wingtips are creating vortices that spiral from below the wing to above the wing
- they actually change the downwash angle of the air flowing over the wing
- tilts the direction of lift created backwards
L/D max is _______
our best glide speed. 68 knots for Cessna to maneuver aloft the longest in case of an emergency
In the backside of the power curb, the pilot will have to _______. In fact, if they want to accelerate out of this airspeed, they will have to _______
- add more and more thrust to counter the high amounts of drag being created.
- add an excessive amount of power or even full power
A thing to keep in mind in slow airspeeds is that ______
there is much less airflow traveling over the flight control surfaces. So it would not have the fast response one would be used to, and it may require large inputs before any real response is felt.
