Aerospace Flight Mechanics

Fuselage, Wings, Empennage or Tail, Powerplant, Landing Gear

Components of an aircraft

Fuselage

The main body of an airplane

Wings

Airfoils attached to each side of the fuselage

Empennage

Known as the tail section

Vertical Stabilizer, Rudder, Horizontal Stabilizer, Elevator

Empennage is consisted of

Powerplant

The heart of the aircraft

Powerplant

A unit or machine that converts chemical energy contains in the fuel to thrust force

Thrust Force

Essential for moving the airplane forward and producing lift force.

Propeller

With the piston engine it is used to convert torque at engine shaft to be thrust.

Jet engine Output

It is the thrust force in the jet engine.

Landing Gear

Located underneath of the fuselage with shock strut

High strength to weight ratio

Light weight

Corrosion resistant

Should be non-flammable

High-quality

Airframe materials properties

Composite material

Most used material now in airframe construction

Wood

Steel & its alloys

Aluminum & its alloys

Titanium alloys

Magnesium alloys

Plastics and composite materials

Example of materials used in airframe construction

Truss Type

Monocoque

Semi-monocoque

Basic Fuselage Structure Types

Pratt Truss

Warren Truss

Two types of truss structure

Truss Type

Most early aircraft used this technique with wood and wire trusses and this type of structure is still used in many lightweight aircraft using welded steel tube trusses.

Monocoque

In this method, the exterior surface of the fuselage is also the primary structure.

Semi-monocoque

This is the preferred method of constructing an all aluminum fuselage.

Formers

Frame

Ring

Bulkhead

The basic structure vertical members

Longerons

Stringers

The basic structure longitudinal members

Semi-cantilever

Type of wing structure where the wing struts are usually attached approximately halfway out on the wing

Spars

Ribs

Stringers

The principal structural parts of the wing

Wing ribs

Determine the shape and thickness of the wing (airfoil)

Fuel tanks

They are either an integral part of the wing structure or consist of flexible containers mounted inside of the wing in most modern airplanes

Ailerons

Flaps

Two types of control surfaces attached to the rear or trailing edges of the wings

Ailerons

Extend from about the midpoint of each wing outward toward the tip and move in opposite directions to create aerodynamic forces that causes the airplane to roll

Flaps

Extend outward from the fuselage to near the midpoint of each and move simultaneously downward to increase the lifting force of the wing for takeoffs and landings

Empennage

The correct name for the tail section of an airplane

Rudder

Elevator

One or more trim tabs

The movable surfaces include

Stabilator

Incorporates a one-piece horizontal stabilizer that pivots from a central hinge point and is moved using the control stick

Rudder

Attached to the back of the vertical stabilizer and is used to move the airplane’s nose left and right

Elevator

Attached at the back of the horizontal stabilizer, and is used to move the nose of the airplane up and down during flight

Trim tabs

Small, movable portions of the trailing edge of the control surface

Landing Gear

The principle support of the airplane when parked, taxiing, taking off, or when landing

Convential landing gear

Landing gear employing a nearmounted wheel

Tail wheel airplanes

Referred to airplanes with conventional landing gear

Nose wheel

When the third wheel is located on the nose

Tricycle gear

The design of the nose wheel

Steerable nose wheel or tail wheel

Permits the airplane to be controlled throughout all operations while on the ground

Powerplant

Includes both the engine and the propeller

Engine

Its primary function is to provide power to turn the propeller

Cowling or Nacelle

The purpose is to streamline the flow of air around the engine and to help cool the engine by ducting air around the cylinders

Propeller

Mounted on the front of the engine, translates the rotating force of the engine into a forward acting force called thrust that helps move the airplane through the air.

Wing Pod Mount

Commonly use on commercial airplane since fuel is carry on wing

Fuselage Mount

Has no ground clearance limitation

1. Long live
2. Repairable / Less maintenance
3. Requirement for graceful degradation

Spacecraft operational characteristics

Payload fairing

Payload / Spacecraft

Payload adaptor

Stage structure

Thrust structure

Typical spacecraft structures

Strutted structure

Central cylindrical shell structures

Two categories of spacecraft structures

Payload fairing

It protects the payload; the frontliner

Heat engine

Converts chemical energy into heat energy

Reciprocating engine

A type of heat engine that derives its name from back-and-forth

Sputnik I

The first satellite that operated until January 3, 1958.

October 4, 1957

When did Sputnik I first operated?

Opposed engine

Most popular reciprocating engine used on light aircraft, 36 hp to 400 hp, has even number of cylinders, high power-to-weight ratios and vibrates less than other engines.

In-line engines

Has an even number of cylinders, aligned in a single row parallel with the crankshaft, liquid-cooled or air-cooled, small frontal area and allows for better streamlining least drag, and limited to four or six cylinders.

V Type engines

Arranged around a single crankshaft in two in-line banks that are 45, 60, 90 degrees apart; had two rows of cylinders, and 8 or 12 cylinders

Radial engines

Consists of a row or rows; greatest drag, lowest weight for horsepower ratios and problems in cooling.

Pratt and Whitney R-4360

The largest multiple-row radial engines

Crankcase

The foundation of reciprocating engine

Cylinders

The powerhouse of the engine/ head and barrel

Pistons

Cylindrical plunger / 4000 F

Connecting rods

Valves

Regulates the flow of gases

Poppet valve

The most common valve.

In-Line and V

Opposed

Radial

Types of engine crankcases

Spark plugs

Ignites air fuel mixtures

Piston Head

Ring Grooves

Ring Land

Piston Pin Boss

Piston Skirt

Piston parts

Plain Type

Master and Articulated

Fork and Blade

Types of connecting rods

Crankshaft

The backbone of a reciprocating engine

Valve Operating Mechanism

Consists of a cam ring or camshaft equipped with lobes that work against a cam roller or a cam follower.

Gas turbine engine (turbo jet)

Sucks in air and compresses or squeezes it. The gases flow through the turbine and make it spin. These gases bounce back and shoot out of the rear of the exhaust, pushing the plane forward.

External Combustion Engine

Internal Combustion Engine

Types of combustion engine

Reciprocating engine

Jet engines

Types of internal combustion engine

Aeolipile

Was invented by Hero, a mathematician in 250 BC.

Dr. Sanford Moss (1900)

Engr. for the General Electri Company who invented turbosupercharger

Sir Frank Whittle

A Royal Airforce Officer and is considered the father of Jet Propulsion. He received the first patent for the Jet Engine (1930)

Hans Von Ohain

The designer of the first operational turbojet engine, a German Engr., Physicist, and Aerodynamicist

Heinkel He-178 Aircraft

World’s first aircraft to fly using the thrust from a turbojet engine. August 27, 1939 was the first successful flight

Jet Propulsion

Propelling force generated in the direction opposite to the flow of mass of gas or liquid under the pressure which is escaping through a hole or opening called jet nozzle.

* Increase the speed of exhaust gases
* Increase the quantity of exhaust gases

Two ways on how to increase jet engine thrust

* Air density
* Air speed
* Air Temperature
* Air Pressure
* RAM Pressure

Environmental factors affecting thrust

* Non-air breathing ( closed)
* Air breathing (open)

Types of reaction engines

* Solid propellant
* Liquid propellant
* Hybrid propellant

Types of rocket propellants

Propellant

The chemical mixture burned

Fuel

A substance that burns

Oxidizer

An agent that releases oxygen

Mixture ratio

The ratio of oxidizer to fuel

Solid propellant motors

Simplest of all rocket designs

* Ram jets
* Pulse jets
* Gas turbine engine

Types of air-breathing engine

Ramjet

Athodyd or aero-thermodynamic-duct that has no static thrust and no moving engine, the simplest

Scramjet

Supersonic combustion ramjet, a variant of ramjet

Pulse jet

Air intake duct is equipped with a series of shutter valves

* Turbojet engine
* Turboprop engine
* Turboshaft engine
* Turbofan engine

Types of gas turbine engine

Turbojet

A type of gas turbine engine that has compressed air

Turboprop engine

A gas turbine engine that delivers power to a propeller

Turboshaft engine

A gas turbine engine that delivers power to a shaft

Turbofan engine

The most efficient and multi-bladed ducted propeller driven by a gas turbine engine

* Low bypass
* Medium bypass
* High bypass
* Ultra bypass

Types of bypass ratios

* Air inlet
* Compressor
* Diffuser
* Combustion Section
* Turbine
* Exhaust

Major sections of gas turbine engine