Aircraft Design

Question 1

Thickness in the wing is?

Answer 1

The distance between the upper surface and the lower surface

Question 2

If engineers are designing an aircraft that will travel to multiple airports, then they have to make sure the _______ doesn’t exceed those airports

Answer 2

wingspan

Question 3

What is load?

Answer 3

The force that deflects flight and produces stress on the aircraft

Question 4

Engineers must optimize safety designs for _______

Answer 4

bird strikes, turbulence, storms, and human errors

Question 5

Stability is the aircraft’s _______

Answer 5

inherent ability to regain equilibrium after it has been disturbed. The stability must also be done by the pilot

Question 6

Flight axes are imaginary _______

Answer 6

lines in which an airplane can turn around.

Question 7

There are 3 flight axes:

Answer 7

lateral axis, longitudinal axis, and vertical axis

Question 8

Lateral axis is _______

Answer 8

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

Question 9

The stability of the lateral axis is called

Answer 9

longitudinal stability.

Question 10

Longitudinally unstable aircraft are _______

Answer 10

difficult and often dangerous to fly. An aircraft that is longitudinally unstable can make deep dives or climbs which could cause a stall.

Question 11

Longitudinal axis is the axis that _______. Turning around this axis is called _______. The stability of this axis is _______, and lateral instability can cause _______.

Answer 11

runs from the nose to the tail of an aircraft

roll

lateral stability

rolls

Question 12

Vertical axis is the axis that _______. Turning around this axis is called _______. The stability of this axis is called _______, which is _______

Answer 12

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.

Question 13

Sweepback:

Answer 13

the backward slant of an airplane wing.

Question 14

Keel effect is when the weight _______

Answer 14

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.

Question 15

Keel area:

Answer 15

the area of the fuselage where the relative wind can affect lateral stability

Question 16

There are advantages and disadvantages to both high wing and low wing aircraft. _______

Answer 16

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.

Question 17

Parasol wings:

Answer 17

placed on struts high above the fuselage of seaplanes, help keep the engine from water spray.

Question 18

Shoulder wing:

Answer 18

a configuration whereby the wing is mounted near the top of the fuselage

Question 19

Aircraft wings are typically made of _______

Answer 19

aluminum or magnesium alloy. Modern aircraft use lighter, stronger materials, such as carbon fiber

Question 20

There are several wing designs such as:

Answer 20

rectangular, elliptical, tapered, trapezoid, delta, ogive, forward-swept, sweptback, and variable designs.

Question 21

Rectangular wings are _______

Answer 21

straight, non-tapered, and used mostly in small aircraft. They are the simplest to manufacture, but they are not aerodynamically efficient

Question 22

Elliptical wings are _______

Answer 22

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

Question 23

Tapered wings are _______

Answer 23

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

Question 24

The delta wing looks like a _______

Answer 24

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

Question 25

Trapezoidal wings have their _______

Answer 25

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.

Question 26

Ogive wings are _______

Answer 26

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

Question 27

Sweepback wings have the leading edge _______

Answer 27

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.

Question 28

Forward-swept wings have the leading edge _______

Answer 28

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.

Question 29

Variable wing design can use _______

Answer 29

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.

Question 30

Wing loading is _______

Answer 30

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.

Question 31

An aircraft high in wing loading will compensate _______

Answer 31

from having a smaller wing by flying faster and generating more lift that way

Question 32

Supersonic:

Answer 32

flight at speeds greater than the speed of sound

Question 33

Subsonic:

Answer 33

flight at speeds less than the speed of sound

Question 34

Transonic:

Answer 34

flight at speeds just under or just above the speed of sound (700-780 mph)

Question 35

Center of gravity (CG) is _______. CG is also the meeting _______. It’s important to consider CG when designing aircraft, but it is equally important to consider _______. Pilots take the load _______. An aircraft too nose-heavy or too aft-heavy is _______

Answer 35

the point where all of the aircraft’s weight is centered point of all the axes that CG will move along the longitudinal axis based on load distribution distribution into account prior to each flight dangerous to fly

Question 36

Carry-on:

Answer 36

a bag or suitcase taken onto an aircraft as handheld luggage. A common sized bag for carry-on luggage is 22"x 14"x 9". Most airlines have a carry-on weight limit of 40 pounds. International airlines may have different restrictions for carry-on luggage.

Question 37

Standard weights are _______

Answer 37

weights that are used as a reference for measuring the weight of other objects.

Question 38

In a small aircraft, pilots can easily determine the effective load balance. For example, _______

Answer 38

if there is one pilot, and one child and adult passenger with no luggage in the back, it would make sense to sit the child in the front and the adult back to distribute the weight evenly. But if there are 200 pounds of cargo in the back, then it would make more sense to sit the adult in front and the child back to compensate for the cargo load.

Question 39

In large commercial aircraft, airlines weigh baggage as it is being _______

Answer 39

checked to determine the cargo weight, and standard weights are used for adult and child passengers, which also includes carry-on allowances. The weight is then entered into a computer system which calculates the CG and load distribution. The computer then generates a plan for the crew to see where to distribute the cargo. For example, the front might be filled with passengers, but the rear is empty, so the plan will specify how much should be loaded in each compartment to compensate for passenger load. After loading cargo, a load sheet is then produced to inform the pilot how the aircraft was loaded and how the CG was calculated.

Question 40

CG is an important concept during flight because it is where _______

Answer 40

the aircraft finds balance

Question 41

Center of lift (CoL) is _______

Answer 41

an important concept, and it is the point at which the wings generate lift. It is always aft of the CG

Question 42

The CoL is also referred to as the _______. Lift would cause the nose to _______

Answer 42

center of pressure (CP) pitch down because of the forward CG, but the tail balances this out by creating downward lift, which allows for level flight

Question 43

G is what happens when the pilot's body _______

Answer 43

is trying to go straight but the direction is constantly changing. This pushes the body outward, and this is called G-force or gravity force

Question 44

G-force is a measure of _______

Answer 44

acceleration. Acceleration is the change in velocity over the change in time (△Velocity/△Time). Velocity is determined by both speed and direction (speed+direction). So even if the speed stays the same, direction is constantly changing, so there is constant acceleration. This outward force is called centrifugal force

Question 45

Centrifugal force is expressed as a _______

Answer 45

multiple of G

Question 46

When we roll towards one direction or the other, some of the lift is _______

Answer 46

pointed horizontally. That horizontal component of lift causes the airplane to turn. But in a turn condition, not only do we have to overcome weight, but we also have to overcome centrifugal force. When we change the direction of travel by adding horizontal lift, we are creating centrifugal force (our airplane wants to continue going straight ahead and that’s the force we have to overcome). So we have to overcome weight and centrifugal force in a turn. When we combine these two, we get a result in force known as the load. Because load is greater than weight, we need to produce more lift in the turn so we don’t descend. Increasing bank angle increases load, so it requires even more lift. Descent turns to wings level also increases load because the airplane wanted to continue descending but stopped. By increasing the load factor, we increase the load our wings have to carry. We measure load factor by G forces or G’s. G’s are simply the force of gravity multiplied.

Question 47

You will find the G limitations for your aircraft _______. Keep an eye on your airspeed so you don’t _______

Answer 47

in the POH or AFM exceed G’s.

Question 48

Load factor is important when considering wing design. _______

Answer 48

Load is a force on the aircraft that deflects from flight and causes stress on the aircraft. It is measured in G’s. A load factor of 3 would mean the aircraft is experiencing a total load of 3 times its weight. Not only would the aircraft experience 3 G’s, but the pilot also would.

Question 49

It’s important for pilots to understand the load factor of the aircraft they are operating. _______

Answer 49

A dangerous load can endanger the aircraft and anyone onboard if the pilot doesn’t understand the aircraft load factor. In addition, a high load factor can also increase the risk of a stall at safe speeds.

Question 50

During the design of an aircraft, the limit load factor _______

Answer 50

is determined, which is the highest load factor at which the aircraft won’t experience structural damage.

Question 51

All aircraft are given their limit load factor under normal operations, which are _______

Answer 51

the operations that an aircraft normally does. For example, an acrobatic plane doing stunt operations is not normal operations for most normal aircraft.

Question 52

Most airplanes can withstand more than the limit load factor _______

Answer 52

to account for quick landings or steep dives.

Question 53

The CFR requires that airplanes can withstand up to 1 and a half the limit load factor, _______

Answer 53

which is referred to as the factor of safety

Question 54

Load factors are determined for each _______

Answer 54

aircraft, depending on its operational category, such as normal, utility, or acrobatic

Question 55

The FAA defines normal aircraft as:

Answer 55

non-acrobatic, weighing 19,000 pounds or less, and having 19 passengers or less, excluding the pilot.

Question 56

Utility aircraft are the same _______

Answer 56

type and size as a normal, but they are approved for limited acrobatics, such as spins or steeper bank angles.

Question 57

Acrobatic aircraft are the same _______

Answer 57

type and size as normal aircraft, but they don’t have acrobatic restrictions

Question 58

Payload refers to?

Answer 58

the total weight of passengers, cargo, or any other objects or materials carried by an aircraft. It represents the useful or revenue-generating load that an aircraft can transport. The payload can include passengers, baggage, freight, mail, or any combination thereof. Fuel is not included. It is calculated by subtracting the empty weight of the aircraft, including fuel, and other necessary equipment, from the maximum allowable gross weight.

Question 59

Newer engineering uses composites to build the fuselage, such as:

Answer 59

fiberglass, carbon fiber, Kevlar, cloth, or a combination. Composites are extremely smooth and easy to use, which help to make a sleek, streamlined aircraft. Carbon fiber is an extremely strong and lightweight material that helps to save fuel during flight

Question 60

Weight and balance are important when considering?

Answer 60

the design of an aircraft. Aircraft that are overloaded have more take off speed, longer runways, lower climbing rate, more fuel burning, less range, lower maximum altitude, less maneuverability, longer landing roll, etc.

Question 61

When designing and constructing an aircraft, the maximum gross weight is determined by?

Answer 61

calculations.

Question 62

Static load is?

Answer 62

the weight of the aircraft itself

Question 63

Dynamic load is?

Answer 63

the load imposed by flight maneuvers

Question 64

An aircraft must be able to support static load and dynamic load. For example:

Answer 64

the wings of 3,000 pound aircraft must support 3,000 pounds during level flight, but on a 60 degree sharp turn, they must support 6,000 pounds of load.

Question 65

It’s vitally important for the pilot to know what about the aircraft’s weight?

Answer 65

the current and accurate weight of the aircraft

Question 66

Periodic weighting of aircraft is _______

Answer 66

desired, but at minimum the aircraft must be weighted after extensive repairs or maintenance.

Question 67

The aircraft weight is always the _______

Answer 67

basic empty weight (BEW), which does not include the weight of fuel, passengers, crew, oil, or cargo.

Question 68

During preflight planning, the pilot must make what about weight?

Answer 68

weight calculations for safe flight.

Question 69

The total weight of an aircraft and where it is placed is _______

Answer 69

critical for flight.

Question 70

When making weight calculations, the pilot must consider what weights?

Answer 70

the basic empty weight (BEW), weight of fuel, passengers and crew, and baggage.

Question 71

A gallon of fuel weighs approximately?

Answer 71

6 pounds.

Question 72

If a pilot needs to reduce weight, they can store _______

Answer 72

less fuel for flight, but the range should be considered when making calculations

Question 73

Balance is the location of?

Answer 73

the center of gravity (CG) in an aircraft. How weight is distributed can impact the balance of the aircraft. Too much weight on the front makes it nose heavy while on the back makes it tail heavy. Unbalanced aircraft are unstable and are harder to fly for the pilot. Think of the aircraft as a teeter totter, an aircraft will fly better if it’s balanced. Many pilots will add baggage to the back to compensate for full fuel and no load on the back.

Question 74

The reference datum is?

Answer 74

an imaginary vertical plane from which horizontal distances are measured for aircraft weight and balance purposes. The datum is determined by the manufacturer, and in small aircraft, the reference datum is often located along the firewall or at the leading edge of the wing.

Question 75

During preflight planning, the pilot will calculate the CG to?

Answer 75

ensure weight and balance. When calculating the CG, pilots will determine the weight using aircraft weight, fuel weight, passenger weight, and cargo weight. An important part of calculating CG is understanding the datum line.

Question 76

The maximum landing weight (MLW) is _______

Answer 76

the maximum aircraft gross weight due to design or operational limitations at which an aircraft is permitted to land. The MLW is set in order to ensure safe landings; if an aircraft weighs too heavy during touchdown, it may suffer structural damage or even break apart upon landing.

Question 77

The maximum take off weight (MTOW):

Answer 77

The MTOW of an aircraft is the maximum mass, defined by the aircraft manufacturer (due to structural or other limits), at which the aircraft is certified for take off.

Question 78

The maximum ramp weight (MRW) (also known as the maximum taxi weight (MTW)) is _______

Answer 78

the maximum weight authorised for manoeuvring (taxiing or towing) an aircraft on the ground as limited by aircraft strength and airworthiness requirements

Question 79

The FAA requires all aircraft to carry the pilot’s _______

Answer 79

operating handbook (POH)

Question 80

What has the datum line and weight balance information for the aircraft?

Answer 80

The POH.

Question 81

When manually calculating CG, _______

Answer 81

weight, moment, and arm are used.

Question 82

Moment:

Answer 82

the product of the weight of an item multiplied by its arm. Moments are expressed in pound-inches (in-lb). Total moment is the weight of the airplane multiplied by the distance between the datum and the CG.

Question 83

Arm:

Answer 83

the distance from the datum to the CG of any component part or any object loaded on the aircraft. When the object or component is located aft of the datum, it is measured in positive inches; if located forward of the datum, it is measured as negative inches or minus inches.

Question 84

How to manually calculate the CG and the gross weight:

Answer 84

Ascertain from the pilot's operating handbook the empty weight of the aircraft and determine the weights of people, baggage, and fuel. Multiply each weight by the arm to find the moment. Add all the weights to get the gross weight. Divide the total moment by the total weight of the aircraft to determine the CG in inches from the datum. This is typically done by filling in a chart.

Question 85

Each aircraft is given an envelope or a CG range by the manufacturer _______

Answer 85

in the form of a chart in the POH. The aircraft will be safe to fly as long as the CG calculations fall within the envelope window or range.