lecture-2 final - airport

CE-363

Lecture 2: Aircraft Characteristics

Dr. Ankit Gupta, Assistant Professor

Department of Civil Engineering

National Institute of Technology Hamirpur

Lecture Outline

Aircraft characteristics

Influence of aircraft characteristics

Aircraft Characteristics

Engine Type and Propulsion

Size of aircraft

Aircraft weight and wheel configuration

Minimum Turning Radius

Minimum Circling Radius

Speed

Capacity

Noise

Vortices at tail ends

Jet Blast

Fuel Spillage



Propulsion may be through any type of engine –

Piston engine, Jet engine (Turbo jet, Turbo propulsion or

Ram jet) or Rocket engine

These may provide speed as high as 500 km/hr, 800

km/hr, 1280 – 2400 km/hr, 4600 km/hr respectively

The aircraft may operate at low, low to high, middle

altitudes. Ram jet is used in missiles and rocket

engine is used for outside atmospheric operations

rokers

Highlight

rokers

Highlight

rokers

Highlight

rokers

Highlight

rokers

Highlight


Size of aircraft

This is defined using basic parameters like

fuselage length (from nose to tail),

gear tread (distance between main gears),

height (at tail),

tail width,

wheel base (distance between nose gear and main

gear) and

wing span (near main gear)


Size of aircraft



Maximum Gross take-off weight (a)

Maximum Structural landing weight (b)

Operating Empty weight (c)

Pay-load (d)

Fuel weight (e)

Zero-Fuel weight (c+d)



a

c (66-44%) d

24 – 16%

e

6 – 40%

Fuel Reserve (4-6%)

b


Aircraft weight and

wheel configuration



While taking a turn, the nose gear is steered and

therefore, makes an angle with the axis of main gear,

called angle of rotation. The point of intersection of

axis of main gear and line through axis of steered

nose gear is called point of rotation.

The maximum angle of rotation is around 50 – 60o

The line joining the centre of rotation and the tip of

farthest wing of the aircraft is known as the minimum

turning radius.


Minimum Turning

Radius



This is the radius in space required for the

aircraft to take a smooth turn. It depends upon

Type of aircraft

Air traffic volume

Weather condition


Speed

Air Speed

Speed of aircraft in air relative to the medium (i.e.

air)

Indicated speed – indicated by the instrument on

board

This is around 2 percent lower than the true speed


Speed


Speed

Ground Speed

Speed of aircraft relative to the ground

Air speed = Ground speed (+/-) wind velocity

Mach 1 ~ equivalent to speed of sound


Speed


Capacity

Defined as the number of passengers and

amount of cargo it can handle

Dependent up on

Size of aircraft

Propulsive power of aircraft

Speed of aircraft


Noise

This is a big problem in the areas where airports are

quite near to the developed areas.

Major sources of noise are

Engine

Machinery (prominent during landing)

Primary jet (prominent during take-off)

Disturbances are more severe during take-off than

during landing

Since the inception of the jet engines, the noise has

reduced due to technological advancement



Vortices are made up of two counter rotating

cylindrical masses extending along the flight

path

These are formed near the tail ends of the

wings or tail end of the aircraft

The velocity of wind in these vortices may be

very high


Jet Blast

This is the blast that comes out of the jet

engine at the rear of the aircraft to provide it

force for movement

Its severity depends up on

Height of the tail pipe from the ground

Angle of the tail pipe

Blast fences need to be erected to control

damage

rokers

Highlight

rokers

Highlight

rokers

Highlight

rokers

Highlight


Fuel Spillage

Spilling of fuel occurs when the engine is shut

down or is losing speed

Influencing Aircraft Characteristics


Size of aircraft




Speed

Capacity

Noise


Jet Blast

Fuel Spillage


Engine Type and Propulsion - decides

Size of aircraft

Speed of aircraft

Length of runway

Weight

Carrying capacity

Noise nuisance

Circling radius

Range

Maintenance facilities

Blast pads, etc.


Size of aircraft

Load carrying capacity

Facilities like size of apron, terminal area, etc

Wing span – taxiway width, separation between traffic

lanes, size of gate, apron size, width of hanger gate

Length – widening of taxiway on curves, size of apron,

hangers, aircraft capacity, width of exit taxiway

Height – height of hanger gate, etc.

Tail width – size of parking and apron

Wheel base – minimum radius of taxiway

Gear tread – minimum turning radius



Thickness of runway, taxiway, apron

Distribution of load through wheels

Generation of revenue

Turning

Stability



Radius of taxiways

Position in the landing aprons and hangers

Path of nose and main gears



Separation of two nearby airports

Adjustment of timings of landing and take-off

aircrafts

Airport capacity

Zoning laws relating to height of an obstruction

(in turning zone area)


Speed

Reduced journey times

Increase in frequency of operations

Broadening of air network


Capacity

Facilities like processing terminals

Passenger and baggage handling

Cargo processing

Need of equipments

Size of apron


Noise

Sleep disturbances, startle

Annoyance

Health risks, deafness, heart attack, etc

Loss of Concentration, attentiveness



Hazardous to the following aircraft due to tail

vortices and wing vortices

Stresses at the joints with fuselage

Pressure on or under the wings producing lifts

or drags


Jet Blast

Inconvenience, discomfort or ever injury to

passengers

Wake velocities and hot exhaust gas may

harm nearby aircraft (if directed towards it)


Fuel Spillage

Seriously affects the bituminous pavement

Slip of wheels

lecture-2 final - airport

Documents