Aero Society of SA

Eskom Expo for Young Scientists

This year’s National Finals for participating schools for Young Scientist’s was held on 4th October 2008 at the University of Pretoria Sports Centre and the Aeronautical Society was present as part of the judging panel.
This is a yearly event sponsored by Eskom to show the best secondary school science projects from around the country and to judge them against set criteria. The best projects out of the various scientific disciplines are then selected for international representation.

For this event, The Aeronautical Society of SA was represented by Prof Japie van Wyk and Dr Rob Hurlin to carry out judging of projects with an Aeronautical flavour. Out of the 484 projects displayed, there were 5 such projects, and each of these were examined.
The project chosen as the best in the Aeronautics sub-category was presented by Grade 10 Sune Gerber from Waterkloof Hoerskool who got to grips with understanding the physics of propeller efficiency. She built a test rig with a balance mechanism and then tested various home made propellers with a given input power from an electric motor from which thrust could be measured in a variable free stream flow (homemade wind tunnel). She was able to produce graphs of propeller efficiency over a range of free stream speeds which showed the correct trend and was able to distinguish between propeller shapes and types in terms of efficiency.

The Society congratulated her on her achievement in gaining an understanding of the principles of flight and presented her with a society cheque and medallion.

AeSSA at AAD 2008
Rob Jonkers

Mr A Maneschijn, Prof. Thomas Jones, Prof. Theo von Backstrom and Mr Lester Ingham were recommended for a Written Paper Prize (a Bronze Award accompanied by the Hodgson Prize) This award is awarded for their paper published in the RAeS Aeronautical Journal last year.

The Hodgson Prize is awarded for a paper on subjects such as policy, law, operations, management, education or history. The following is the abstract of the journal paper.

Various programmes are underway internationally to establish legislative instruments for regulating civil and military unmanned aerial vehicles and systems. An analysis of a selection of these programmes revealed that the approaches used for airworthiness regulation are not harmonised and are usually limited to specific unmanned aerial vehicle types, indicating the need for a generic framework for airworthiness requirements.

A functional Reference Framework for unmanned aerial vehicle and system airworthiness requirements was developed using Annex 8 of the Chicago Convention as a reference basis, supplemented with airworthiness procedures and functional requirements derived from manned aircraft regulations, unmanned aerial vehicle and system airworthiness material, and flightworthiness guidelines for reusable launch vehicles. Various airworthiness elements were identified for which further research is required to develop appropriate airworthiness requirements. This paper summarises the development of the framework and proposes the Reference Framework as a functional basis for generating comprehensive South African civil and military airworthiness requirements for unmanned aerial vehicles and systems.

As the President of the Royal Aeronautical Society Capt. David Rowland visited SA for the Aeronautical Symposium and AAD, it was very appropriate for the team to be awarded their prize here in SA, and what better opportunity than at the Symposium gala dinner held at Spier in Stellenbosch on the evening of the 15th September. There, Capt David Rowland congratulated the team on their work that gained a prestigious entry into the Society’s Journal.

Lester Ingham, Anto Maneschijn, Prof Thomas Jones, Capt David Rowland,
Prof Theo von Backstrom

Kosie van den Heever (MAeSSA) of Denel Dynamics has been accepted as a corresponding member of the Engineering Sciences Data Unit (ESDU) Aerodynamic Technical Committee. Kosie will be involved in the review process of Aerodynamic Data Items for ESDU before publication. This establishes Kosie as an aerodynamic specialist, recognized on an international level - indeed something to be proud of.

ESDU publishes validated, up-to-date engineering data to design engineers in aerospace, mechanical, chemical and structural engineering. The data includes methodologies, guidance, equations and software.

ESDU originated in 1940 when the Royal Aeronautical Society responded to the critical need for engineers to support the expanding aircraft industry. The specialized knowledge required for aircraft design was captured in a working tool for engineers. The Society established a Technical Department to bring together the best available knowledge and present it in an authoritative and accessible form.

The data units are still generated in the same way as when ESDU started. Permanent technical staff at ESDU prepare the data units, which are reviewed by Technical Committees, comprising international specialists such as Kosie. This combination of professional staff and voluntary specialists results in validated data units that meet industry requirements.

Craig Peters, of Denel Dynamics, presented the above lecture in the company's auditorium to about 60 members and guests, following the AGM of the Society on 28 May 2008. Craig graduated in Electro-mechanical Engineering, with considerable distinction, from Cape Town University in 2005, and joined Denel Dynamics the following year. Apart from the simulation work he covered in his lecture, he has been engaged in research projects involving a Micro-gas turbine engine and in RF Proximity fuze evaluation, in both of which he acquitted himself extremely well.

The lecture presented an interesting insight into the use of MSC ADAMS (Advanced Dynamic Analysis of Mechanical System) software in integrating the kinematics of a missile seeker gimbal system with its control system, modeled in MathWork's Simulink, to produce a very realistic animated simulation of of the seeker dynamics in tracking an acquired target. The already well proven gimbal of the R-Darter radar seeker was used as a benchmark for the technique, and produced remarkably accurate results as well as information regarding the hitherto unknown dynamic loads acting on individal components in the gimbals.

It is clear from this work that the method will find wide application in many areas of Aeronautical Engineering. Indeed, ADAMS software has been successfully used by Denel Dynamics in the design and analysis of UAV undercarriage systems and in studies involving the separation of booster rockets from a missile. But with the combination of Simulink and the introduction of Finite Element generated elastic behaviour of structures into the simulation, the field of application appears limitless.

A PLAN FOR DEVELOPMENT IN RC MODEL FLYING
Dr Rob Hurlin, Pr Eng, PhD (Eng), FRAeS
May 2008

South Africa has an urgent need for technical skills, particularly in aviation. Many young people have a passionate interest in aviation, but do not have access to a means to develop this interest. Radio Controlled flying provides an affordable means for young people to fly an aeroplane and to learn the basics of flight. The development of this passion will lead many young people into a career in aviation, perhaps as a pilot, crewmember, technician, engineer, business manager, lawyer, medic or one of many other opportunities.

Read Dr Hurlin's report on a plan for getting young people involved in model flying. The plan was originally proposed by Allen Fraser of Frasers Radio Control Models (Lynnwood, Pretoria). Allen is also the Chairman of the Silverton Model Flying Club and is on the SAAMA development committee.

The Society was able to secure a lecture on Aerodynamics, in fact fairly fundamental Aerodynamics where all the traditional explanations were challenged. Dr Holger Babinsky was touring SA and agreed to provide a lecture to the Society on his acclaimed study of lift concerning aircraft wings. Wits University kindly hosted the event on the 3rd of April and the lecture had a turn out of over 70 people.

The science behind aeronautics continues to fascinate and many students are attracted to engineering as a result of an early interest in aircraft. The most commonly asked question is how a wing can produce lift. Unfortunately the most widely used explanation of lift is wrong in a number of key points. Not only is this confusing for students, but in the worst case it can lead to a fundamental misunderstanding of some of the most important aerodynamic principles.

The above diagram demonstrates the folly of one of the popular myths that particles
will meet up on the other side of a body travelling in a flowfield.

Without going into the detail of the lecture, Dr Babinsky explained that the key to the understanding of how lift is produced is in the pressure gradient that is prevalent across curved streamlines, where pressure increases in the direction away from the centre of the curvature.

For any budding Aerodynamisct and members who wish to truly understand the science of the air and its movement, Dr Babinsky’s work is a must read, where the mysteries are explained in science fact. Information on the lecture provided and detail theory behind this can be found on the Cambridge University web site.

RC TECHNOLOGY
AND FLYING DEMONSTRATION
SWARTKOPS AIR FORCE BASE
an article by
Dr Rob Hurlin
April 2008

Our concept for this event started with the idea of bringing members of the AeSSA up to date with the latest technology in Radio Control Flying. When Gen. Thackwray started negotiating with the SAAF Museum at Swartkops AFB it was suggested that we combine our function with the Museum open day on 1 March 2008. Arrangements were duly made with Col. Spolander (OC) and Lt. Col. Shepherd (Admin Ops Officer) of the SAAF Museum. READ more.....

THE JOHN WESTON MEMORIAL LECTURE
19 March 2008
Dr Paul Potgieter
CEO Aerosud

The Aeronautical Society of South Africa held one of its prestigious lecture series at Aerosud on the 19th of March, this being the John Weston Memorial Lecture which is held every two years. The individual nominated for this lecture is selected as somebody who has contributed significantly to the South African Aerospace Industry, and is awarded a gold medal from the Society.

This year Aerosud’s Dr. Paul Potgieter was nominated for this prestigious award, and gave a lecture on his “Vision for the Future of SA Aerospace”. Salient points of his lecture covered a historical perspective of the SA industry having gone through 4 eras, that of Self Sufficiency – in the heydays of Rooivalk & Cheetah, post 1994 Defence Packages – Gripen, Hawk and Agusta, Globalisation – with the SAA fleet renewal providing a much needed boost, and more recently the Government’s dti initiative to take part in risk and revenue sharing projects.

The question is asked, why should there be growth in the SA Industry? – Paul provided a very enlightening perspective on his view on growth prospects and business opportunities in this sector primarily stemming from:

· The realisation that we can
· We have the labour, business and technical skills
· Government’s initiatives are supportive, the Department of Trade and Industry (dti) having created industrial participation mechanisms, the Department of Science and Technology (dst) having created research structures and the Industrial Development Corporation (IDC) being able to provide financing capabilities.

Aerosud has been the benchmark in the SA Aerospace Industry in capitalising on winning contracts throughout the changing environment to achieve long term business viability and now has a sustainable global customer base and a reputation of being a reliable supplier.

Aerosud is now focusing on further organic growth, expansion of facilities, building further industry links and most importantly the development of the supply chain into second tier levels. This supply chain development is critically linked to the establishment of the Centurion Aviation Village as the enabler of involving the required supporting industries.

Aerosud’s ultimate future vision is to climb the value chain in Aeronautical products and become a smart supplier of significant aircraft structures and eventually be an OEM of its own products.

The lecture was held in Aerosud’s Innovation and Training Centre on splendid Autumn evening and was concluded with the Society President Rob Jonkers handing over the John Weston gold medal and congratulated Paul on his contribution to the success of the Aerospace Industry.

THE ALLISTER MILLER MEMORIAL LECTURE
Presented by
JOHN T MORRISON
CHIEF EXECUTIVE
AIRLINES ASSOCIATION OF SOUTHERN AFRICA
to the
AERONAUTICAL SOCIETY OF SOUTH AFRICA
7 NOVEMBER 2007

Although the title of the presentation “The Dynamics of Aviation Viability in Southern Africa” conjures up an image of gloom in the aviation world, John gave some insight in to the opportunities that are wanting if the various countries Governments in Southern Africa saw their way clear to reduce restrictions in airline operations to enable an “Open Skies” course of action to take hold. Currently, all inter-country routes and airlines operating between countries are regulated which stifles competition and is monopolistic and hence fares tend to be expensive. Currently, the Airlines Association is working hard to break the current log jams that are in place, as being successful in “Opening the Skies” will bring tremendous benefit to all the countries in Southern Africa and will provide a surge of Aviation related development.