# 1507NSC Aviation Science Assignment-Griffith University Australia.

Weight: 20% of course
Style: Article & video
Length: One article-report 1500 – 2000 words (single-spaced 12 font) and four 1 min videos
Marking: It will be marked out of 100.
During the lectures, you learned that there are four main forces (usually called airborne forces) acting on an aircraft while it is flying:
• The Lift (FL) acting vertically upwards,
• the Gravitational Force or Weight (FG), acting vertically towards the Earth,
• the Thrust of the engine (FT), pulling horizontally forwards, and
• the Drag (FD), acting horizontally backwards.
Each of these vector forces may act in different ways depending on the flight stage that we consider: take off, climb, cruise, approach or landing.
1507NSC Aviation Science Assignment-Griffith University Australia.

Task: Write an article-report analysing the Physics dynamics of flying.
Assume that your report is to be used to train some of your colleagues at work who have not completed a degree of aviation. You are requested to:
I. Explain in scientific but straightforward terms, the equilibrium conditions of an aeroplane cruising.
II. Explain how tail planes can help balance and control those conditions of equilibrium.

Following you will find guides that will help you to write your report. They include specific questions that you must cover and calculations that you must complete as guiding examples.

PART I: Equilibrium conditions
In your report, you must include answers to the following questions using the information from your lectures or any other external sources appropriately referenced:

• Identify the airborne forces as vectors acting on the aircraft. Where on the aircraft (with respect to its centre of mass) each of these forces act?, What is the common name for those positions?, e.g. the Gravitational force acts on the centre of gravity which on Earth coincides precisely with the centre of mass of the aeroplane.
• Include an original free body diagram and an original extended free body diagram representing the ideal disposition of the four main forces acting on an aeroplane during the five different stages of flight. Explain your diagrams and describe the effect of each of these forces in the aeroplane translation and rotation. Include the angle of attack. You can use the table at the end of this document
• Using your diagrams, establish what are the translational and rotational conditions of equilibrium of these four forces during the cruise stage? Write down and explain the equations that determine these conditions.
• Are these four forces likely to change in value or to move their position of action during the flight? If they do, under which conditions do they vary? What are the effects of those changes?

Exemplar calculations for real-life situations
Using M to be the last digit in your s number and N the first two digits. (e.g. s 1234567, N=12 and M=7)Record a 1 min video showing and explaining how to solve the following real life situation

The inertia of an aeroplane is M x103kg. It carries N passengers with average inertia of 60 kg at a certain constant speed in cruising flight, the ratio of lift to drag of the complete aircraft is 6 to 1

1507NSC Aviation Science Assignment-Griffith University Australia.

What are the values of the lift, thrust and drag? Use your free body diagrams and equations of equilibrium to solve this problem.

PART II: Tail planes and the difficulties in balancing the four forces while cruising

• How does the ideal disposition of the four forces in an aircraft relate to the nose-up or nose-down pitching moments? What are the difficulties that the pilot can face to maintain such an ideal disposition for each of the forces while cruising?
• Do these forces values and positions depend on the airspeed and the angle of attack? How?
• Would it be beneficial for the pilot to control the position of action of these principal forces? What positions are controllable? What would happen if all the forces were concentrated in the centre of mass all the time? Would this affect the ability to manoeuvre the aircraft?
• What is a tail plane? What is the effect of a tail plane in the dynamics of the aircraft? Why is it usually called lifting tail? Why is it also called stabiliser? Compare the characteristics of the adjustable tail plane and the slab tail plane in a table. Include photographs of aircraft with such tail planes.
• How does a tail plane act in an aircraft designed for routine flight? For high speeds? For low speeds? The force exerted by the tail plane is called the lifting-tail load (FLT) include this vector force in a new extended free-body diagram for each speed case in cruise mode. Evaluate and explain the new conditions of equilibrium and express them mathematically.

Exemplar calculations for real-life situations
Using m to be the first digit of your s number and n the last digit(e.g. if s=1234567, m=1 and n=7). Record a 1 min video showing and explaining how to solve the following real life situation. Include detailed and explained working out to solve this problem. Use your free body diagrams to help you find a solution. Identify the translational (x and z) and rotational (y and z) conditions of equilibrium. Introduce these problems as exemplary applications of the concepts discussed in this part:

An aeroplane of m x 104 kg mass is designed with the line of thrust n x 10-1 m above the line of drag. In routine flight the drag is 15.2 k N, and the centre of pressure on the main plane is 200 mm behind the centre of mass. If the centre of pressure on the tail plane is 12 m behind the centre of mass, what is the lifting-tail load (FLT)?

1507NSC Aviation Science Assignment-Griffith University Australia.

Final notes:

• All photographs, diagrams and sources must be referenced appropriately (for information on proper referencing and plagiarism, you can use the Griffith University Academic Integrity
• Please use Harvard, print journal, article style of referencing.
• Articles will be checked with anti-plagiarism software (Turnitin), so be very careful to follow all of the guidelines on the website. Any detection of plagiarism or misconduct will be immediately reported and prosecuted.
• Make sure your article is well structured and has clear headings.