Part 1: Historical and Societal influences of Flight a. 1884-1892
Known as a gentlemen inventor, Lawrence Hargrave, was the first Australian to design monoplane wing designed aircraft. Hargrave based his inventing by ‘following the footsteps of nature’ inspired by the motion of fish, snakes and birds.
1893, 1894
Hargrave invent the box kite and following year in 1894 he flies for a short period using a ‘train’ of four box kites.
1910
The first powered, control flight is demonstrated by a visiting Harry Houdini in Victoria and again at Rosehill in Sydney.
1912-17
In 1912 the Australian Flying Corps, AFC, in 1912 led the path aircraft for military purposes. The aircrafts were applied in 1914 and again in 1916 for war purposes. In 1916 the importance of aircraft was realised and the NSW Aviation School was formed to train civil and military aircraft, located at Richmond. Post war saw the aircrafts as a form of transport between Sydney and Melbourne in 1917 using a Curtiss Jenny and Caudron G111.
1921
To further advance the power of potential of air power, the Royal Austrlian Air Force, RAAF, was established in 1921. This was mainly to support the struggling aircraft in the military however at the same time a fundamental character, Lt Colonel Oswald Watt advanced the safety and use of civil aircraft.
1930-37
Australia and England led the way for the world of female pilots. Qantas and Royal Flying Doctor Service took advantage of the new transport and the air craft industry began to flourish.
1950s
The demand for new aircraft to carry more customers resulted in the wide-body aircraft the success of the Boeing 707 saw the industry sky rocket. From here on the basic commercial air craft design was established and Qantas began to purchase.

b.
A major event during the history of flight in Australia was a home grown invention of the black box or flight data recorder. Dr David Warren from Melbourne Aeronautical Research Laboratories made the invention in 1953 and it was in production by 1957. The recorder records the communications between the pilots and the information of the instrument/ computers, all encased in high strength material. The black box had a huge significance as it became the key to solving disaster investigations. In many cases the crashes are horrific and most of the plane is destroyed along with the crew and passengers but the tough materials of the black box ensure its survival and protection of vital data. The box will send out a distress signal to speed up the recovery time and potentially save lives.
c.
The advancements in materials lead to the super tough recorder designed to survival the most devastating crashes. Aluminium has great corrosion resistant properties and used to case the vital memory cards. Dry silica can with stand temperature of 1600 degrees and is use to protect the memory devices in the post crash fires. However the real toughness and strength comes from the stainless steel casing, 0.46cm thick. This material has very high strength and toughness properties, often titanium is used for the outer layer for simular properties.
d.
The nature of what an aeronautical engineer does throughout his/her career is to design, develop, test aircraft, missiles and space vehicles. The engineer will often specialise in one kind of vehicle for example helicopters. Majority of aeronautical engineers are employed in the aircraft industry. Aeronautical engineers work closely with other specialists to develop new materials for the improvement of aircraft.
Aeronautical engineering mainly revolves around the transport of humans at great speeds and with speed comes danger and responsibility for safety. The security of the passengers and crew can be ensured through design, assembly, testing and repair. The creative aspect of an aeronautical engineer is to design propulsion mechanisms, flight simulators, support equipment and communication systems. The process is often done firstly on a blue print then transferred to a computer for 3D models, ensuring the weight is evenly distributed in respect to the plane. Once the design is complete it is time to move into the physical. The engineer will often have smaller scale models assembled before the prototype; the engineer will oversee the entire project and decide if changes should be made to improve strength and efficiency. Testing is vital to ensure the aircraft will function as it should without failure. Tests are preformed to design and improve by using high pressure wind tunnels and flight simulators. However often disasters can begin at microscopic levels and a range of tests can be carried out, further detail later in the assessment. Once the problems have been identified it is time to repair. Engineers are responsible for the method used to repair and maintenance schedules.
Aeronautical engineering includes missiles, bombers and many other air born aircraft which can be used to kill humans and destroy the environment. This is a huge ethical topic. Weapons are always the last resort and used to fight ‘evil’. Engineers are often critised for the weapons however most engineers simply improve the materials and structure. Such weapons are often developed in times of desperation, such as the atomic bomb with the intention of stopping Hitler.
e. Vortex Generators
Aircrafts generate the lift through the speeds which flows above and below the wing generating different pressures. These pressures can be varied due to the environment/ turbulence and stalling. To avoid this is the innovation of vortex generators has been applied. Air flows above the wing but the air is ‘free’ and tends to flap off, not the entire flow goes over the wing. The vortex generator assists the lift by creating a disturbance between the free air and the fast flowing air closer to the wing, the result is more lift. This allows the aircraft to be more efficient and manoeuvre at lower speeds. The same principal has been allied to car and other earth bound vehicles to produce downward force.

Part 2.
a.
Aluminium is being used much more in modern times for its corrosion resistant properties and its much lighter than steel. However steel is still used in the aircraft, aircraft cannot afford to develop cracks or fail. Steels can weld to be as strong as the parent materials however aluminium cannot do the same; it will be weaker than the parent material in most cases.
b.
Fatigue cracks usual occur in airframes, rotating shafts, bearings, aircraft wings and engine connection rods as a result of environmental exposure and cyclic loadings. Non-destructive testing used to inspect for fatigue cracks because the components of aircraft are expensive.
The application of testing for cracks is often internal and extremely small therefore special testing is used. X-ray tests are fired through the material and defects are detected by either film or fluorescent screen. X-rays can be used to detect cracks, blowholes and voids in cast however not suitable for forgings.
Fluorescent penetrate testing is when the test subject is soaked in penetrate fluid and allowed to be absorbed. It is then dried out and a developing powered is applied which will cause cracks to appear luminous under ultra-violet light. Penetrate testing can be used on metals and to observe manufacture flaws and fatigue aggravated cracks.
Ultrasonic flaw detection is when ultrasonic vibrations are used on one side of the components being tested and the time is recorded. The time variants indicate flaws. This test can be used to detect extremely small flaws, can be used on all materials.
In recent times new technology is changing the methods of testing, an example of this is holograph interferometer testing. This method involves no contact with the test subject and a laser creates patterns on the material, defects in the pattern determine flaws.
c.
The ‘skin’ of the aircraft is the final layer of the aircraft between the atmosphere and the structure; it is the defence from the elements. Aluminium is a great corrosion resistant material however is soft and lacks great strength properties. However it can be hot-rolled onto a sheet of strong alloy to protect the alloy from corrosion. This is known as an alclad composite. Duralumin is a great example and is composed of aluminium, copper, magnesium and manganese.
Part 3
a.
Innovations in materials are always driven by cost, performance and efficiency. Aircrafts will always perform greater if they are lighter in weight however not at the sacrifice of strength. If an aircraft can have a longer performing span it will have much more value, another factor driving improvements of materials.
b.
Reasons why Aluminium Alloys are used instead of pure aluminium:
- Greater strength to weight ratio
-Greater stress corrosion cracking and fatigue resistance
-Improved stiffness and resistance to bending
c.
The rivet would be made from a selected aluminium and copper alloy. Once the rivet has been manufactured it is a matter of time before it is hardened for the purpose of holding together. In order to the slow the process the rivet is keep cool until it reaches the same diameter of the drilled hole on the aircraft. Once it is right it is inserted using a riveting gun and make a ‘soft’ entry and in time will gain strength properties and hold the two components firmly.
d.
A composite material is a combination of two or more individual materials of different composition to form a new material, a composite. The resultant material of the composition has a combination of the individual materials, superior properties. These compositions first came about form observations of nature, for example timber. Timber is composed of complex strands and glued together by a weaker material; the result is a strong material. Humans observed this and noticed when basic materials were combined it formed stronger ones. The first known composition was the mud brick, a combination of straw and mud. Today many great materials are being formed using the same principle on a micro scale creating materials with amazing properties.

e.
Carbon fibre reinforced plastic:
Application: Tailplane and elevator, aileron, spoiler shroud top panel, flap track fairings, inner air brakes, doors, engine cowls, leg firings, access panels, flaps and spoilers.
Properties/reason: Light weight, high strength to weight ratio, high fatigue strength, good corrosion resistance, low thermal expansion, low impact resistance, high electric conductivity.
Aramid fibre reinforced plastic:
Application: Fin/ Fuselage fairing, floor panels
Properties/reason: Strength, elasticity, compression strength, electrical strength.
Glass fibre reinforced plastic:
Application: Belly fairing skins, radome.
Properties/reason: Strength, elasticity, heat resistance.
Part 4 a. All forward facing surfaces of an aircraft are suspect to erosion from high speed collision with rain drops. These can include fuel tanks and munitions. The rate of erosion can be varied by the amount of rain or the velocity of the collision. When rain hits the subject it can cause huge amounts of pressure to build at high speeds, which an aircraft usually travels at. This pressure can be too much for the material and erosion occurs or cracking leading to corrosion. Laminates are used to ‘shield’ the plane from rain erosion, as the rain erodes the layers of the laminate the high speeds can cause it to delaminate. This is a mode of failure for composites and leads to shear forces damaging the materials properties. b. Dissimilar metals are often critical in leading edge aircraft where specific properties are required. These are used in aircraft flying at greater than the speed of sound, landing gear and fasteners. Minor differences in materials can lead to anodic and cathodic surfaces which will breed corrosion.
There are several ways of reducing and preventing galvanic corrosion. One method is via electrical insulation which is separating the two using an insulator such as plastic. Another method is to keep the metals dry which is to keep them protected from ionic compounds such as salt. This can be achieved by painting the metal with plastic or epoxy. If it is only possible to coat one of the two metals the noble metal will be coated to minimise the corrosion area. The final method is to choose metals with simular potentials, if the potentials are small the overall current will be and therefore less galvanic corrosion. This is best achieved by choosing the same material however batches tend to vary slightly.

c. Fasteners are coated in: * Hi-Kote 1,2,4 * Cadmium Plate * IVD Aluminium * Anodize (Ti, Al) * Cetyl Alcohol Lube
Bibliography
Websites: Address: http://www.hsc.csu.edu.au/ Last updated: 2012 Address: http://www.rfcafe.com/references/general/galvanic-series.htm Last updated: 2010 Address: http://www.lincolnelectric.com.au/articles/page358/article491 Last updated: 2011 Books: Title: Excel Engineering studies Author: P Metcallefe Published: 2011