Airport Planning L28: Aircraft Characteristics Dr. Rajat Rastogi, Associate Professor
Airport Planning
L28: Aircraft Characteristics
Dr. Rajat Rastogi, Associate Professor
Lecture Outline
• Aircraft characteristics
• Influence of aircraft characteristics
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Aircraft Characteristics
• Engine Type and
Propulsion
• Size of aircraft
• Aircraft weight and
wheel configuration
• Minimum Turning
Radius
• Speed
• Minimum Circling
Radius
• Capacity
• Noise
• Vortices at tail ends
• Jet Blast
• Fuel Spillage7/18/2016 11:45 AM
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Engine Type and Propulsion
• Propulsion Type –
• Piston engine, Jet engine (Turbo jet, Turbo propulsion or
Ram jet) or Rocket engine
• Speeds: 500 km/hr, 800 km/hr, 1280 – 2400
km/hr, 4600 km/hr respectively
• Altitudes low, low to middle and high altitudes
• Ram jet is used in missiles and rocket engine is
used for outside atmospheric operations7/18/2016 11:45 AM
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Engine Type and Propulsion
• Specific Fuel Consumption – Fuel required to
create thrust of 1 lb
• Factors influencing:
• Weight of aircraft
• Altitude
• Speed
• Engine’s Bypass Ratio ????7/18/2016 11:45 AM
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Size of Aircraft
• Basic parameters -
• 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)
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Size of Aircraft
Tail width
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Aircraft Weight
• Operating Empty weight (OEW) - a
• Pay-load (PL) - b
• Zero-Fuel weight (ZFW) – c = a+b
• Maximum Structural Pay-load = (ZFW – OEW)>b
• Maximum Ramp Weight (MRW): Apron to
Runway end
• Trip Fuel Weight (TFW)
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Aircraft Weight
• Maximum Gross Take-off weight (MGTOW) - d
• Maximum Structural Take-off weight (MSTOW):
at sea level, Temp. 15oC, Standard Design
Wheel weight
• Maximum Structural landing weight (MSLW): e
Weight for which landing gear is designed
• Landing weight MSLW
• Tae-off weight MSTOW
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Aircraft Weight
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d
a (66-44%) b
24 – 16%
TFW
6 – 40%
Fuel Reserve (4-6%)
c
MRWe
Aircraft Wheel Configuration
• Aircraft weight and wheel configuration
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Minimum Turning Radius
• Angle of Rotation – Angle made by nose gear with
the axis of main gear while turning
• The maximum angle of rotation is around 50 – 60o
• Point of Rotation - The point of intersection of
axis of main gear and line through axis of steered
nose gear
• The line joining the centre of rotation and the tip
of farthest wing of the aircraft is known as the
minimum turning radius
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Minimum Turning Radius
• Minimum Turning Radius
• R = WB*Tan(90 - ) + t/2
• WB = Wheel Base
• = Steering angle
• t = Wheel track
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Minimum Circling 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
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Speed of Aircraft
• Air Speed
• Speed of aircraft relative to the medium
(i.e. air), depending upon air density
• Indicated speed – indicated by the
instrument on board
• This is around 2 percent lower than the true
speed at each 330 m (1000ft) above sea level
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Aircraft Speed
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Aircraft Speed
• Ground Speed
• Speed of aircraft relative to the ground
• Air speed = Ground speed (+/-) wind velocity
• Mach 1 ~ equivalent to speed of sound
• Speed of sound = 33.4 T0.5 miles per hr
• T = Temperature in degree Rankine
• 1 knot = 1 naum/h (1 nautm = 6080ft = 1.15
land mile)7/18/2016 11:45 AM
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Aircraft Speed
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Aircraft Speed - Performance
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• Do-Not Exceed speed (Vne)
• Design Maneuvering Speed (Va)
• Lift-off Speed (Vlo)
• Rotate Speed (Vr)
• Decision Speed (Vl)
• Stall Speed (Vso)
• Reference Landing Approach Speed (Vref)
• Vref = 1.3 * Vso
Aircraft Capacity
• Defined as the number of passengers and
amount of cargo it can handle
• Dependent up on
• Size and design of an aircraft
• Propulsive power of aircraft
• Speed of aircraft
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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)
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Aircraft Noise
• Disturbances are much more sever during
take-off than during landing
• Since the inception of the jet engines, the
noise has reduced due to technological
advancement
• Aircraft noise is less damaging than road
traffic noise ????
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Vortices at Tail Ends
• 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
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Vortices at Tail Ends
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Aircraft 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 round
• Angle of the tail pipe
• Blast fences need to be erected to control
damage
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Fuel Spillage
• Spilling of fuel occurs when the engine is shut
down or is losing speed
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Influencing Aircraft Characteristics
• Engine Type and
Propulsion
• Size of aircraft
• Aircraft weight and
wheel configuration
• Minimum Turning
Radius
• Speed
• Minimum Circling
Radius
• Capacity
• Noise
• Vortices at tail ends
• Jet Blast
• Fuel Spillage7/18/2016 11:45 AM
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Engine Type and Propulsion
• Size of aircraft
• Speed of aircraft
• Length of runway
• Weight
• Carrying capacity
• Noise nuisance
• Circling radius
• Range
• Maintenance
facilities
• Blast pads, etc.
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Size of an 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
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Size of an Aircraft
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Chūbu Centrair International Airport
Asheville Regional Airport
Size of an Aircraft
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Size of an Aircraft
• Height – height of hanger gate, etc.
• Tail width – size of parking and apron
• Wheel base – minimum radius of
taxiway
• Gear tread – minimum turning radius
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Aircraft weight and wheel configuration
• Thickness of runway, taxiway, apron
• Distribution of load through wheels
• 5% on nose gear and rest on landing gears
• Generation of revenue
• Turning
• Stability
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Minimum Turning Radius
• Radius of taxiways
• Position in the landing aprons and hangers
• Path of nose and main gears
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Minimum Circling Radius
• 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)
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Aircraft Speed
• Reduced journey times
• Increase in frequency of operations
• Broadening of air network
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Capacity and Range
• Facilities like processing terminals
• Passenger and baggage handling
• Cargo processing
• Need of equipments
• Size of apron
• Range proportional to Payload
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Noise
• Sleep disturbances, startle
• Annoyance
• Health risks, deafness, heart attack, etc
• Loss of Concentration, attentiveness
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Vortices at Tail Ends
• Hazardous to the following aircraft due to tail
vortices and wing vortices
• Tangential velocities ~ weight of aircraft and
inversely proportional to speed
• More intense when near the airport
• Stresses at the joints with fuselage
• Pressure on or under the wings producing lifts
or drags
• Wake-turbulence classification of aircraft7/18/2016 11:45 AM
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Jet Blast
• Inconvenience, discomfort or ever injury to
passengers
• Wake velocities and hot exhaust gas may harm
nearby aircraft (if directed towards it)
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Fuel Spillage
• Seriously affects the bituminous pavement
• Slip of wheels
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?????