Flight dynamics (fixed-wing aircraft)

Question 1

The three critical flight dynamics parameters

Answer 1

The three critical flight dynamics parameters are theangles of rotationin threedimensionsabout the vehicle’scenter of mass, known aspitch,rollandyaw.

Question 2

Attitude

Answer 2

a vehicle’s orientation (attitude) about itscenter of mass.

the relative orientation of the Earth and body frames describes the aircraft attitude.

Question 3

actuators

Answer 3

The control systems include actuators, which exert forces in various directions, and generate rotational forces ormomentsabout theaerodynamic centerof the aircraft, and thus rotate the aircraft in pitch, roll, or yaw. For example, apitching momentis a vertical force applied at a distance forward or aft from the aerodynamic center of theaircraft, causing the aircraft to pitch up or down.

Question 4

moments

Answer 4

rotational forces.

For example, apitching momentis a vertical force applied at a distance forward or aft from the aerodynamic center of theaircraft, causing the aircraft to pitch up or down.

Question 5

steady flight

Answer 5

Steady flight,unaccelerated flight, orequilibrium flightis a special case inflight dynamicswhere the aircraft’s linear and angular velocity are constant in abody-fixed reference frame.

Question 6

wings level or zero bank angle

Answer 6

The equilibrium roll angle

Question 7

heading

Answer 7

yaw

Question 8

trim

Answer 8

The equilibriumpitch anglein submarine and airship parlance is known as “trim”, but in aircraft, “trim” usually refers to the equilibriumangle of attack, rather than orientation.

Question 9

longitudinal axis

Answer 9

The most common aeronautical convention defines the roll as acting about the longitudinal axis, positive with the starboard (right) wing down.

Question 10

vertical body axis

Answer 10

The yaw is about the vertical body axis, positive with the nose to starboard.

Question 11

longitudinal plane of symmetry

Answer 11

Pitch is about an axis perpendicular to the longitudinal plane of symmetry, positive nose up.

Question 12

angle of attack

Answer 12

Afixed-wing aircraftincreases or decreases the lift generated by the wings when it pitches nose up or down by increasing or decreasing theangle of attack(AOA).

Influid dynamics,angle of attack(AOA, or{\displaystyle \alpha }(Greek letteralpha)) is theanglebetween areference lineon a body (often thechord lineof anairfoil) and thevectorrepresenting the relative motion between the body and the fluid through which it is moving.

Some authors[3][4]do not use an arbitrary chord line, but use thezero lift axis, whereby zero angle of attack corresponds to zerocoefficient of liftby definition.

Question 13

fixed-wing aircraft

Answer 13

Afixed-wing aircraftis anaircraft, such as anaeroplane, which is capable offlightusingwingsthat generateliftcaused by the vehicle’s forwardairspeedand theshape of the wings. Fixed-wing aircraft are distinct fromrotary-wing aircraft, in which the wings form a rotor mounted on a spinning shaft, andornithopters, in which the wingsflapin similar manner to abird.

Question 14

bank angle

Answer 14

The roll angle is also known as bank angle on a fixed-wing aircraft, which usually “banks” to change the horizontal direction of flight.

Question 15

drag

Answer 15

Influid dynamics,drag(sometimes calledair resistance, a type of friction, orfluid resistance, another type offrictionor fluid friction) is aforceacting opposite to the relative motion of any object moving with respect to a surrounding fluid.

An aircraft is usually streamlined from nose to tail to reducedragmaking it typically advantageous to keep the sideslip angle near zero, though there are instances when an aircraft may be deliberately “sideslipped” for example aslipin a fixed-wing aircraft.