Air legislation - mantenance, planning and organisation - Essay Example

Abdullah Alshafi 4 May Effect of Centre Of Gravity On The Aircraft: Take-off , Landing And CruiseCenter of gravity (cg) is a point inside or outside a body through which the whole weight of the body appears to be acting. For an aircraft, the center of gravity position depends on, and is controlled by balancing the overall size and mass distribution characteristics including the effect produced as a result of the consumption of fuel. Center of gravity calculations are of critical importance during aircraft design.

Figure 1. Weight distribution due to different components of an aircraft.For stability of the aircraft during take- off, landing and cruise , the center of gravity of the aircraft must fall within the limits and range specified for a particular type and make of an aircraft as established by the manufacturer.The aircraft is capable of rotation along the three axes namely; Pitch ,Roll and Yaw, in addition to a linear motion along the specific air route when in- flight. For any type of movement shown by the aircraft ,the weight of the aircraft must be balanced out to maintain the position of the center of gravity for stability.

An air craft can have Lateral center of gravity, Longitudinal center of gravity and even Vertical center of gravity. The most important if these being the Lateral cg, which has a critical role in stabilizing the pitch of the aircraft. Lateral cg is further partitioned into Forward and Aft cg. There are limits to the Fore and Aft cg positioning. If the Fore and Aft cg is out of range the aircraft may pitch uncontrollably up or down during take-off ,flight or landing. For example if the cg is too far forward , the plane is likely to tilt forward or crash Alshafi 2upon take-off.

Figure 1. Effect of shift in Longitudinal cg on the pitch of an aircraft. The Lateral cg position is to be maintained in order to control and stabilize any unwanted roll movement during any stage of flight. The position of Lateral cg can shift if there is an uneven distribution of fuel in the tanks,or in case of an uneven seating arrangement of passengers in a small aircraft. Figure 3 Effect of shift in Lateral cg on the Roll of an aircraft during flight. The Vertical cg position is associated with the stability of the flight along the yaw axis.

A shift in the vertical cg can result in yawing motion if not compensated for by the pilot during take-off, flight and landing. Alshafi 3 The vertical cg position may be shifted even due to cross winds. This results in a sidewise motion of the aircraft during flight.Figure 4.Effect of change in Vertical cg on the yaw of an aircraft.The change in the Vertical cg of the aircraft can disturb the course during flight.During landing the aircraft can experience problems due to the sidewise movement and may miss the landing.

The center of gravity is a major factor in the stability of an aircraft in all the phases of flight ; take-off ,cruise / flight and landing. A disturbance in the longitudinal, lateral or vertical cg can upset the movement of the aircraft along either of the three axes ;pitch , roll or yaw. Alshafi 3 References1. ^ http://en.wikipedia.org/wiki/Center_of_gravity_of_an_aircraft/ n.d. Centre of Gravity of an Aircraft. n.p. Web. 4 May,2012.2. ^ http://www.flightlearnings.com/2011/03/12/balance-stability-and-center-of-gravity/ 12 March, 2012 “Balance,Stability and Center of Gravity”. n.p. Web. 4 May, 2012. 3 .^ http://www.grc.nasa.

gov/WWW/k-12/airplane/acg.html 11 July 2008.Benson,Tom. “ Center Of Gravity –cg. Aircraft Application. ” Web.5 May, 2012.4. ^https://fn2win.fusonet2.com/Training/prodapp.nsf/929995be16ff3b0e8525679e0064 5811/772729171976c32285256cfc0071c0f1?OpenDocument 28 March, 2003.”Vetrical Center of Gravity. ”n.p .Web.5 May 2012 5. ^ http://www.flightlearnings.com/2009/08/21/aircraft-design-characteristics-part-one- vertical-stability-yawing/ 21 August 2009.“Aircraft Design Characteristics( Part Four)-Vertical Stability (Yawing )’’.n.p. Web .5 May 2012.