Aircraft Design Flashcards
Thickness in the wing is?
The distance between the upper surface and the lower surface
If engineers are designing an aircraft that will travel to multiple airports, then they have to make sure the _______ doesn’t exceed those airports
wingspan
What is load?
The force that deflects flight and produces stress on the aircraft
Engineers must optimize safety designs for _______
bird strikes, turbulence, storms, and human errors
Stability is the aircraft’s _______
inherent ability to regain equilibrium after it has been disturbed. The stability must also be done by the pilot
Flight axes are imaginary _______
lines in which an airplane can turn around.
There are 3 flight axes:
lateral axis, longitudinal axis, and vertical axis
Lateral axis is _______
an axis that runs from one wing tip to the other, and turning around this axis is called pitch. This is the most affected axis
The stability of the lateral axis is called
longitudinal stability.
Longitudinally unstable aircraft are _______
difficult and often dangerous to fly. An aircraft that is longitudinally unstable can make deep dives or climbs which could cause a stall.
Longitudinal axis is the axis that _______. Turning around this axis is called _______. The stability of this axis is _______, and lateral instability can cause _______.
runs from the nose to the tail of an aircraft
roll
lateral stability
rolls
Vertical axis is the axis that _______. Turning around this axis is called _______. The stability of this axis is called _______, which is _______
runs down through the aircraft perpendicular to the wings and fuselage
yaw
directional stability
easy to achieve because of the vertical fin and fuselage design.
Sweepback:
the backward slant of an airplane wing.
Keel effect is when the weight _______
acts as a pendulum and swings the aircraft back into position when the relative wind disturbs lateral stability. This mostly affects high wing aircraft since they have a large keel area.
Keel area:
the area of the fuselage where the relative wind can affect lateral stability
There are advantages and disadvantages to both high wing and low wing aircraft. _______
The higher the wing, the less need for dihedral. The higher the wing, the easier it is to fly the aircraft because of the increased stability due to the improved pendulum effect.
Parasol wings:
placed on struts high above the fuselage of seaplanes, help keep the engine from water spray.
Shoulder wing:
a configuration whereby the wing is mounted near the top of the fuselage
Aircraft wings are typically made of _______
aluminum or magnesium alloy. Modern aircraft use lighter, stronger materials, such as carbon fiber
There are several wing designs such as:
rectangular, elliptical, tapered, trapezoid, delta, ogive, forward-swept, sweptback, and variable designs.
Rectangular wings are _______
straight, non-tapered, and used mostly in small aircraft. They are the simplest to manufacture, but they are not aerodynamically efficient
Elliptical wings are _______
the most aerodynamically efficient wings because they allow for the least possible amount of drag and thinness. A drawback is that they are hard to manufacture
Tapered wings are _______
similar to rectangular wings, but instead they get tapered towards the tips and allow similar lift distribution as elliptical wings. They are not as aerodynamically efficient as elliptical wings, but they are easier to manufacture
The delta wing looks like a _______
triangle, and they have a large surface area. It is mostly used in supersonic flights for supersonic aircraft, but it’s also efficient for subsonic and transonic flights. They have a high maneuverability because of their low wing loading. Delts wings are structurally sound, and they have a large area for fuel. They are also simple to manufacture and maintain. One disadvantage is that at low speeds they have a large AOA and more drag
Trapezoidal wings have their _______
trailing edge sweeped forwards and the leading edge backwards. This wing design provides great flight performance and is commonly used in US combat aircraft. They are also highly efficient for supersonic flights and have good stealth characteristics. One disadvantage is that its high wing loading decreases its maneuverability.
Ogive wings are _______
a complex and mathematically difficult design used for high-speed aircraft to reduce drag during supersonic flight. Although they have excellent performance during supersonic flight with little drag, they don’t perform well in subsonic. Because they are so intricate, they are hard to manufacture. They are often called “Concorde wings” because the retired Concorde has been the only airplane with these types of wings
Sweepback wings have the leading edge _______
swept back. They are used for less drag in transonic flight. The majority of commercial aircraft use this design because they allow for faster flight with less drag.
Forward-swept wings have the leading edge _______
swept forwards. It had controllability issues and it was only used in a few aircrafts. Although it has an unusual design, it allows for more maneuverability. It allows for a steeper angle of airflow without a stall. In WWII, Germans created this concept, but it never went past its prototype. In 1984, NASA and the Air Force partnered and made the X-29 to experiment with the design. It proved to be more maneuverable at high speeds, but the project was discontinued in 1992.
Variable wing design can use _______
combinations to adapt over different range speeds to optimize performance. For example, at high-speed flight, such as supersonic or transonic, sweepback is better. But at low speeds like subsonic, non-swept is better. A disadvantage of the design is its high mechanical complexity.
Wing loading is _______
the total weight of the airplane divided by the area of the wings. Aircraft high in wing loading sometimes need more distance for landing and take off, and they are also less maneuverable.
An aircraft high in wing loading will compensate _______
from having a smaller wing by flying faster and generating more lift that way
Supersonic:
flight at speeds greater than the speed of sound
Subsonic:
flight at speeds less than the speed of sound
Transonic:
flight at speeds just under or just above the speed of sound (700-780 mph)