Reference no: EM133144923

1507NSC Aviation Science - Griffith University

During the lectures, we learned that there are four main forces acting on an aircraft while it is flying:

• the lift (FL) acting vertically upwards (relative to the airframe),
• the gravitational force or weight (FG), acting vertically towards the Earth,
• the thrust of the engine (FT ), pushing horizontally forwards (relative to the airframe), and
• the drag (FD), acting horizontally backwards (relative to the airframe).
Each of these vector forces may act in different ways depending on the five flight stages that we consider: take off, climb, cruise, approach or landing. In addition, the aircraft will experience a normal force when in contact with the ground, and friction between the ground and landing gear.

Task: Write a report (in two parts, as outlined below) discussing and analysing the dynamics of flying.

Assume that your report is to be used to educate a scientist or engineer who understands the fundamentals of mechanics but has no prior aviation experience. You are requested to, in scientific but straightforward terms, explain:
I. the equilibrium conditions of a cruising aeroplane.
II. how tailplanes can help balance and control those conditions of equilibrium.
Below, you will find scaffolding 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.

Other: Please observe the following:

• All non-original photographs, diagrams and sources must be referenced appropriately in the bibliography section below (you do not need to reference your own original diagrams). Use the AGPA Harvard style of referencing

PART I: Equilibrium conditions

Construct a response to the following prompts and 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) do 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 coincides precisely with the centre of mass of the aeroplane.
• Include an original free body diagram (essentially, treat the plane as a point mass) and an original extended free body diagram (showing where each of the four forces act relative to the centre of mass) representing the ideal disposition of the main forces acting on an aeroplane during each of the five different stages of flight. Explain your diagrams and describe the effect of each of these forces in the aeroplane's translation and rotation. Include the angle of attack. Use the table below.
• Using your extended free-body diagrams, establish 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?

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

Construct a response to the following prompts and questions using the information from your lectures or any other external sources (appropriately referenced):
• How does the ideal disposition of the four forces in an aircraft relate to the nose-up or nose- down pitching moments (torques)? 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 acted through the centre of mass all the time? Would this affect the ability to manoeuvre the aircraft?
• What is a tailplane? What is the effect of a tailplane on the dynamics of the aircraft? Why is it called a ‘horizontal stabiliser'? Compare the characteristics of adjustable tailplanes and slab tailplanes in a table. Include photographs of aircraft with these tailplanes.
• Many modern aircraft are configured such that the tailplane provides no lift when in level flight near the nominal cruise speed. Is the tailplane still useful when the aircraft is cruising near its nominal cruise speed? What happens at higher and lower speeds? Prepare new extended free-body diagrams for each speed case, showing the contributions of lift from the tailplane (FTP) and all other flight surfaces (FMP, which is primarily from the mainplane/wings). Explain the conditions of equilibrium in terms of FTP and FMP, and express them mathematically.

Attachment:- Aviation Science.rar