What is an Aircraft

8/6/2019 What is an Aircraft

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What is an aircraft?

vehicle which flies by gaining support from

the air in general, the atmosphere of a planet

counters the force of gravity by either staticlift or by using the dynamic lift or downward

thrust from jet engines.



Classification

� Lighter-than-air aircraft called Aerostats,

examples balloons and blimps.

�

Heavier-than-air aircrafts called Aerodynesinclude autogyros, helicopters and fixed

winged aircrafts.

� Fixed winged aircrafts use IC engines or

Turbine engine( jet or turbo prop)



Parts of an Airframe



� Fuselage: portion contains the crew and

payload, either passengers, cargo.

� they are long, cylindrical tubes or sometimes

rectangular box shapes.

� wing: produces the lift that allows a plane to

fly.

� The wing is made up of two halves, left and

right, connected to each other by means of

the fuselage



�A wing produces lift because of its special

shape, a shape called an airfoil



Engine

� Can be classified in two major categories

� propeller-driven piston engines and jet

engines.� larger planes, have engines mounted in

separate pods hanging below the wing or

attached to the fuselage. These pods are

called nacelles.



Turboprop engine



� uses most of the energy from the hot exhaust

gases to drive a propeller

� jet core produces about 15 percent of the

thrust while the propeller generates the

remaining 85 percent.

� the turboprop engine employs as large aturbine as possible, for this is its main source

of power

�more efficient than turbojets on designed tofly at speeds below about 800 km/h



Jet engine

Schematic of a simple jet engine



� obtains its oxidizer from the external

atmosphere

� compressed air is then mixed with fuel,

typically a petroleum-based liquid similar to

kerosene, and burned.

� The high-pressure gas is exhausted through anozzle to generate thrust.



Horizontal stabilizer

� aircraft consisting of only a wing or a wing andfuselage is inherently unstable.

� also known as the horizontal tail, acts as astabilizer when aircraft is disturbed in pitch.

� horizontal tail is a miniature wing of an airfoilcross-section.

� produces a force pointed downward, aquantity called downforce to maintainequilibrium



Vertical stabilizer

� functions in the same way as the horizontaltail but provides stability for a disturbance inyaw.

� if a disturbance causes the nose to deflect toone side, the vertical tail produces acounteracting force that pushes the nose inthe opposite direction to restore equilibrium.

� vertical tail produces a force pointed to oneside of the aircraft called side-force.



Basic Control Surfaces



Elevator

� located on the horizontal stabilizer.

� can be deflected up or down to produce achange in the downforce produced by the

horizontal tail.

� The angle of deflection is considered positivewhen the trailing edge of the elevator is

deflected upward.� the downforce produced by the horizontal tail

increases causing the nose to pitch upward.



Rudder

� located on the vertical stabilizer.

� can be deflected to either side to produce achange in the side-force produced by the

vertical tail.

� angle of deflection is positive when thetrailing edge of the rudder is deflected

towards the right wing.� This creates a side-force to the left which

causes the nose to yaw to the right.



Aileron

� located on the tips of each wing.

� deflected in opposite directions to produce a

change in the lift produced by each wing.� The wing with more lift rolls upward causing

the aircraft to go into a bank.

�

angle of deflection is positive when theaileron on the left wing deflects downward

and that on the right wing deflects upward.



Aircraft control surfaces and positive deflection angles



Additional Components



� Flap: usually located along the trailing edge of

wings, typically inboard of the ailerons and

close to the fuselage.

� only deflect downward to increase the lift

produced by both wings simultaneously.

� often used during takeoff and landing toincrease the lift the wings generate at a given

speed.

�Slats: leading-edge flaps, more often calledslats, are also used to increase lift



� cabin & cockpit: cockpit is a compartment at

the front of the fuselage where the pilots and

flight crew sit.

� contains the control yolks (or sticks) and

equipment the crew use to send commands to

the control surfaces and engines as well as tomonitor the operation of the vehicle.

� cabin is typically a compartment within the

fuselage where passengers are seated



� Nose & main gear:

�

The landing gear is used during takeoff,landing, and to taxi on the ground

� Most planes today use a tricycle landing gear

arrangement.



Flight control systems

Consists of control surfaces, respective cockpit

controls and necessary operating mechanisms

to control the aircraft in flight.

Primary Control surfaces

Fly-by-wire

Digital Fly-by-wire

FADEC (Full Authority Digital Engine control)



Flight Management System

It is composed of four major components

FMC (Flight Management Computers)

AFS (auto Flight Systems)Navigation system including IRS and GPS

EFIS (Electronic Flight Instrument System)



Electrical systems

� Primary function is to generate, regulate and

distribute power throughout the system

�

Used to operate aircraft flight instruments,essential systems and passenger services

� Different sources of power include engine

driven AC generators and APUs (Auxiliary

Power Units)

What is an Aircraft

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