Weight and balance

EMPTY WEIGHT GROSS WEIGHT

USEFUL LOAD (PAYLOAD)

All aeroplanes are designed for certain limit loads and balance conditions. Responsibility for making sure that the weight and balance limitations are met before take-off rests with the pilot. Any pilot who takes off in an aeroplane that is not within the designated limit load and balance condition is not only violating the regulations but inviting disaster. Three kinds of weight must be considered in the loading of every aircraft:

a) _______________ - The weight of the basic aeroplane - the structure, the powerplant, and the fixed equipment, all fixed ballast, the unusable fuel supply, undrainable oil, and hydraulic fluid.

b) _______________ - The weight of pilot, passengers, baggage, useable fuel, and drainable oil.

c) _______________ - The empty weight plus the useful load of the aeroplane at takeoff. When an aeroplane is carrying the maximum load for which it is certificated, the takeoff weight is called the maximum allowable gross weight.

Understand that although an aeroplane is certificated for a specific maximum gross weight, it will not safely take off with this load under all conditions. For example, conditions that affect takeoff and climb performance-high elevations, high temperatures, and high humidity - may require the ‘off loading’ of fuel, passengers, or baggage. Other factors to be considered are runway surface, runway length and the presence of obstacles.

In most modern aeroplanes, the pilot has a loading option. He must decide the type mission to be flown and load his plane accordingly.

Not only must the pilot consider the amount of load he carries, he must also determine that the load is arranged to fall within the allowable centre of gravity range specified in the aeroplane weight and balance data. The centre of gravity location, often indicated by the letters ‘CG’, is the point where an aeroplane will balance. The allowable range where the CG may fall is called the CG range. The exact location of the range, usually near the forward part of the wing root is specified for each type of aeroplane. Obtaining this balance is simply a matter of placing loads so that the average arm of the loaded aeroplane falls within the CG range. In many modern aircraft, this can be accomplished by using common sense in distributing the load by following placards in the aircraft. For an increasing number of light aircraft, however, passengers and/or baggage can be loaded in a manner that makes it easier to exceed the centre of gravity range.

In such instances considerable care must be exercised if one is to be certain that the aircraft is properly loaded. Currently light aircraft manufacturers provide the data, graphs, charts, and instructions required in computing the weight and balance conditions for specific aeroplanes at specified gross weight and load placement. Every pilot should be familiar with and understand the use of such materials.

Дата добавления: 2015-07-11