![]() ![]() On the wing or aerofoil, it is also the point where the resultant force of the lift / drag couple acts. Depending on various factors, including the location of the surface, the pressure force may be greater or less, so the centre of pressure is the average point of the sum of all these pressures. When an aircraft travels through the air, pressure acts on the body and surfaces of the aircraft. It is the point on the chord line of an aerofoil (a line through the aerofoil joining the leading edge and the trailing edge), where all the aerodynamic forces are concentrated. Either way, exceeding the limits is highly unfavourable, causing increased drag, higher fuel consumption, reduced range and endurance.Ĭentre of pressure is different in that it is concerned with aerodynamics, not mass. Exceeding the the rear CG limit results in a nose-up attitude, which means a decrease in longitudinal stability and ‘light stick forces’. Safe forward and aft CG limits are established by aircraft manufacturers, and due consideration to these limits should be respected in all phases of flight.Įxceeding the foward CG limit causes the aircraft to have a nose-down attitude, increases longitudinal stability, which then requires significant elevator deflection. In aircraft with swept-back wings, like those on most modern airliners, the centre of gravity is expressed as %MAC or percentage of Mean Aerodynamic Chord – a topic for another discussion – but the main reason for this is that the wings are not straight and uniform The chord used for measurement therefore needs to be averaged, and the centre of gravity is then expressed as a percentage.ĬG is primarily concerned with mass and movement, but its importance lies with the stability and controlability of the aircraft. There are limits to the CG movement, known as the CG envelope, and these are published in the aircraft flight manual. ![]() For example, consider that fuel is used during flight, or passengers that move about. The CG does not remain at a fixed position and will move during flight, either forwards or rearwards, depending on the distribution of weight in loading, and the operation of the aeroplane. The force of gravity acts on the total mass of the aeroplane in a vertically downward manner at this point (the CG), and is also known as the centre of balance. The centre of gravity (CG) is probably more commonly understood, and refers to the point in an object (the aeroplane) at which all the mass is considered to be concentrated. Especially for student pilots, these two can be somewhat confusing, so we will look at the differences between the two, and how each is affected under various flight conditions. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |