Aircraft Mass Estimation Methods - IJEMR

1 Volume-4, Issue-5, October-2014, ISSN No.: 2250-0758. International Journal of Engineering and Management Research Available at: Page Number: 170-178. Aircraft Mass Estimation Methods Sowmya Thyagarajan1, Navuday Sharma2. 1,2. Amity Institute of Space Science and Technology, Amity University, INDIA. ABSTRACT. Weight minimization of an airplane design is a gravity and the positioning of the landing gear and the wings. subject of extreme importance considering the aspect of cost In this paper various weight Estimation techniques has been Estimation . While considering the design of large airplanes reviewed.

2 This review does not consider getting into details of reduction of weight is done at some high performance particular method, rather a brief description of various designs. In various cases reduction of weight in one Methods and interesting features have been presented here. component leads to added weight in the other, leading to the The focus has been given on commercial transport airplane. snowball effect of the weight growth. The prospect to achieve a weight reduction and the costs depend upon the phase of the design process. The Aircraft 's mass is required to Keywords - Aircraft design, Centre of gravity, Commercial calculate flight performance and to assess the design.

3 Transport, Weight minimization. Individual masses are required to determine the centre of I. INTRODUCTION. Weight prediction in the preliminary sizing is essential the design. During the initial conceptual design the choice for the performance prediction, centre of gravity of the airplane layout, geometry and detailed configuration determination, design of the undercarriage and providing affects weight. The design layout should be carefully weight limits to various departments. Good weight optimized and high accuracy of the initial weight Estimation starts with clear definitions and effective prediction is a prerequisite.

4 Weight prediction is necessary subdivision of the items. The airplane is composed of a not only to make an assessment of the design qualities, but large number of parts which can be combined into groups also to set a goal for the structural and systems design according to several schemes. The weight of these groups offices. The initial weight prediction must be a realistic and several combinations of groups are of importance in challenge. During detail design it is essential to save every small made. The Aircraft weight is Estimation is done by item of weight that can possibly be saved, in order to subdividing the parts into various groups, ensure a high standard of weight predication accuracy and to continuously monitor the weight, using an effective Airframe structure: The wing group, the tail group, the weight control system.

5 In order to save weight, the use of body group, the gear group and the engine nacelle group. advanced materials and sophisticated manufacturing The surface controls group may be classified as airframe techniques may be considered, resulting in a reduction of structure or as a part of the airframe services. the amount of material required. The weight saving may be used to reduce the takeoff weight or to increase the Propulsion group: The engines, items as associated with payload or fuel load. However, the cost involved may lead engine installation and operation, the fuel system, and to a noticeable increase in the price of the airplane and as thrust reversing provisions.

6 Assessment of the value of, the weight saving should be Airframe equipment and services: APU's, the hydraulic, Operational Items: are those items of personnel, electric and electronic systems, furnishings and equipment, equipment and supplies that are necessary on a particular air-conditioning, anti-icing systems and other equipment. operation, unless already included in the basic empty A further subdivision into fixed and removable equipment weight. These items may vary for a particular airplane is useful for obtaining an accurate and repeatable empty configuration according to the operator's allowances for weight definition.

7 The service intended. However, a minimum crew is defined for each airplane by government regulations. Fixed equipment and services: they are considered an integral part of a particular Aircraft configuration. These Section2 describes some of the mass Estimation include the weight of fixed ballast and the fluids which are Methods . Section 3 gives a brief explanation about the contained in a closed system. Methods involved in wing mass Estimation . Section 4. describes the fuselage mass Estimation . Section 5 deals Removable equipment and services: are those with the tail plane mass Estimation .

8 Section 6 explains the items of equipment or system fluids that are not considered other structural mass Estimation . an integral part of a particular Aircraft configuration. Removable separating walls, passenger seats, floor covering, basic emergency equipment. I. SECTION 2 affecting weight in graphical method may be hard enough, and may prove impractical because there will be separate trends based on choice of material, maneuver loads, Mass Estimation Methods fuselage layout, type of engine integrated, wing shape, control architecture ( , FBW is lighter), and so forth.

9 Mass Estimation at the conceptual design stage should be The simplest form, as explained here gives a preliminary predicted appropriately in advance of detailed drawings of estimate of component and Aircraft weight. At the the parts that are being prepared. Statistical adaptation of conceptual design stage, when there is a stage where only data from the past designs is the means to predict the technology has to e adopted and a three-view drawing are accurate component mass at the conceptual design phase. when only the technology level to be adopted and the During the conceptual design stage, iterations are three-view drawing are accessible to predicted weight.

10 Important when the configuration changes. Typically, there However, with severe analyses using semi-empirical are three Methods [5] used in evaluating mass ( , weight) prediction, better accuracy can be achieved. estimations at the conceptual design stage: Semi-Emphirical Method Rapid Method This method is considered to be more efficient, here it uses This method depends on the statistical average of mass semi-empirical relations derived from a theoretical one level below major Aircraft components. The mass is background and evaluated by actual data that has been expressed in terms of percentage (alternatively, as a statically correlated.)