Geometry of an Aircraft

Question 1

Name the Part of the Plane (excluding D and E)

Answer 1

A-Tail unit (Empennage)

B-Rudder

C-Elevators

F-Ailerons

G-Wings

H-Powerplant

I-Fuselage

J-Leading edge

Question 2

Fuselage

Answer 2

Has a Truss Structures

Two types; Monocoque-Shell is the primary load carrier, Semi-Monocoque- Frames (Formers) around fuselage, Stringers (Longerons) aligned nose to tail

Typically Aluminium

Question 3

Undercarriage

Answer 3

Needs to be strong

About 5% of the aircraft weight

Can contain Landing gear

Question 4

Powerplants

Answer 4

Two types: Props and Jets

Question 5

Tail unit

Answer 5

Provides stability and control

Contains Rudder anf Elevators

Question 6

Wing

Answer 6

Provides Lift

Can contain fuel

Question 7

Definition: Chord

Answer 7

Distance between Leading and Trailing edge of a wing

Question 8

Root Chord

Answer 8

The length of the centre line of a wing

Question 9

Sweep Angle

Answer 9

Conventionally measured along the quarter chord line

Increases speed and reduces Transonic Drag

Question 10

Aerodynamic Centre

Answer 10

Usually located close to the quater chord line

It is fundamental to understanding tand eevaluation of the stability of an aircraft

Question 11

2 Types of Mean Chords

Answer 11

1. Standard Mean Chord (SMC)- Same area and span. Purely geometric
2. Mean Aerodynamic Chord (MAC)- Same area, aerodynamic force and position of the centre of pressure at a given angle of attack

Both measures of the chord of an equivalent rectangular wing sharing attributes with the real wing

Question 12

Dihedral wing angle

Answer 12

Low wing

Maneourvability

Question 13

Anhedral wing angle

Answer 13

High wing

Stability

Question 14

S

Answer 14

Wing Area

Question 15

b

Answer 15

Span

Question 16

Aspect ratio, AR

Answer 16

High AR= Lower thrust requirements

Induced drag is proportional to 1/AR

Problems with high AR

• Bending moments
• Maneouverability
• Other forms of drag dominate

Question 17

Wing Tips

Answer 17

Increase effective AR

Lower lift-induced drag (Vortices)

Increases othe types of drag

Adds weight to ends of wings

Question 18

Name the different parts of an Aerofoil

Answer 18

• Leading Edge
• Trailing Edge
• x_t=Distance to t_max
• x_c=Distance to sigma
• t_max=Max thickness
• sigma=Camber
• r₀=LE Radius

Question 19

For a symetric aerofoil…

Answer 19

0 lift at 0^o angle of attack

Question 20

Add-ons to a wing

Answer 20

Slats to the LE, delays stall

Flaps to the TE, reduces lift+increases drag

Spoilers, “”

Question 21

3 Axes of control

Answer 21

1. Roll
2. Yaw
3. Pitch