Calculo de Peso y Balance

8/4/2019 Calculo de Peso y Balance

1/59

WEIGHT & BALANCE

AERODYNAMICS

1ARTURO E RIVERA R. LIC IET 164
https://www.flightsafety.com/


2/59

ARTURO E RIVERA R. LIC IET 164 2


3/59

WEIGHTS

STANDARD WEIGHT

EMPTY:

The weight of theairframe and engine with

all standard equipment

installed. It also includes

the unusable fuel and oil.Empty weight 787-3 : 223,000 lb (101,200 kg)Empty weight 787-8 : 242,000 lb (110,000 kg)Empty weight 787-5 : 230,000 lb (105,000 kg)



4/59

OPTIONAL OR EXTRA

EQUIPMENT

Any and all additionalinstruments, radioequipment, etc., installedbut not included asstandard equipment, theweight of which is added

to the standard weightempty to get the basicempty weight. It alsoincludes fixed ballast, full

engine coolant, hydraulicand de-icing fluid.



5/59

BASIC WEIGHT EMPTY

The weight of the airplane with all optional

equipment included. In most modern

airplanes, the manufacturer includes full oil

in the basic empty weight.



6/59

USEFUL LOAD

(OR DISPOSABLE LOAD)

The difference between gross take-off weight

and basic weight empty. It is, in other words,

all the load which is removable, which is not

permanently part of the airplane. It includes

the usable fuel, the pilot, crew, passengers,

baggage, freight, etc.



7/59

PAYLOAD

The load available as passengers, baggage,

freight, etc., after the weight of pilot, crew,

usable fuel have been deducted from the

useful load.

A 320 Typicalvolumetric

payload

16.6 tonnes 36.59 lbs. x1000



8/59

OPERATIONAL WEIGHT EMPTY

The basic empty weight of the airplane plus

the weight of the pilot. It excludes payload

and usable fuel.

A 320 Typical

operating

weightempty

42.4 tonnes 93.5 lbs. x

1000



9/59

USABLE FUEL:

Fuel available for flight planning.



10/59

UNUSABLE FUEL:

Fuel remaining in the tanks after a runout

test has been completed in accordance with

government regulations.



11/59

OPERATIONAL GROSS WEIGHT:

The weight of the airplane loaded for take-

off. It includes the basic weight empty plus

the useful load.



12/59

MAXIMUM GROSS WEIGHT:

The maximum permissible weight of the

airplane.



13/59

MAXIMUM TAKE-OFF WEIGHT:

The maximum weight approved for the start

of the take-off run.

A 320

Maximumtakeoff

weight

73.5 (77)tonnes

162 (169.8)lbs. x 1000



14/59

MAXIMUM RAMP WEIGHT:

The maximum weight approved for ground

manoeuvring. It includes the weight of fuel

used for start, taxi and run up.

A 320

Maximum

ramp weight

73.9 (77.4)

tonnes

162.9

(170.6) lbs.x 1000



15/59

ZERO FUEL WEIGHT:

The weight of the airplane exclusive of usable

fuel.


A 320 C


16/59

A 320 METRIC IMPERIAL

Maximumtakeoffweight

73.5 (77)tonnes

162 (169.8)lbs. x 1000

Maximumlandingweight

64.5 (66)tonnes

142.2 (145.5)lbs. x 1000

Maximumzero fuel

weight

61 (62.5)tonnes

134.5 (137.8)lbs. x 1000

Maximumfuel capacity

23,860(29,840)

Litres

6,300 (7,885)US gal.

Typicaloperatingweight empty

42.4 tonnes 93.5 lbs. x1000

Typicalvolumetric

payload

16.6 tonnes 36.59 lbs. x1000



17/59

PASSENGER WEIGHTS:

Actual passenger weights must be used in computingthe weight of an airplane with limited seatingcapacity. Allowance must be made for heavy winterclothing when such is worn. Winter clothing may add

as much as 14 lbs to a person's basic weight; summerclothing would add about 8 lbs. On larger airplaneswith quite a number of passenger seats and for whichactual passenger weights would not be available, the

following average passenger weights may be used.The specified weights for males and females includean allowance for 8 lbs of carry-on baggage.



18/59

Summer

Winter

Males (12yrs&up) 182 lbs 188 lbs

Females (12yrs&up) 135 lbs 141 lbs

Children (2-11 yrs) 75 lbs 75 lbs

Infants (0-up to 2 yrs) 30 lbs 30 lbs



19/59

FUEL AND 0IL:

The Airplane Flight Manuals for airplanes of U.S.manufacture give fuel and oil quantities in U.S. gallons.Canadian manufactured airplanes of older vintage mayhave manuals that give fuel and oil quantities in

Imperial gallons. Some recently printed manuals maygive fuel and oil quantities in litres. At most airports inCanada, fuel is now dispensed in litres. It is thereforenecessary to convert from litres to U.S. or Imperial

gallons as required for your particular airplane. Toconvert litres to U.S. gallons, multiply by .264178. Toconvert litres to Imperial gallons, multiply by.219975.



20/59

LITRE U.S. GALLON IMP. GALLON

AVIATION

GAS1.58 lb. 6.0 lb. 7.20 lb.

JP-4 1.76 lb. 6.6 lb. 8.01 lb.

KEROSENE 1.85 lb. 7.0 lb. 8.39 lb.

OIL 1.95 lb. 7.5 lb. 8.5 lb.



21/59

MAXIMUM LANDING WEIGHT:

The maximum weight approved for landingtouchdown.



22/59

MAXIMUM LANDING WEIGHT:

Most multi-engine airplanes which operate overlong stage lengths consume considerable weightsof fuel. As a result, their weight is appreciably less

on landing than at takeoff. Designers takeadvantage of this condition to stress the airplanefor the lighter landing loads, thus savingstructural weight. If the flight has been of short

duration, fuel or payload may have to bejettisoned reduce the gross weight maximum ormaximum landing weight.



23/59

MAXIMUM WEIGHT - ZERO FUEL:

Some transport planes carry fuel in theirwings, the weight of which relieves; thebending moments imposed on the wings by

the lift. The maximum weight - zero fuel limitsthe load which may be carried in the fuselage.Any increase in weight in the form of load

carried fuselage must be counterbalanced byadding weight in the form of fuel in the wings.



24/59

MAXIMUM WEIGHT - ZERO FUEL:



25/59

DATUM (DATUM O REFERENCE

DATUM). Es el plano vertical imaginario a partir del cual

se miden todas las distancias a efectos debalance y determinacin del centro de

gravedad. La localizacin de esta referencia laestablece el fabricante.



26/59



27/59

THE BALANCE DATUM LINE

is a suitable line selected arbitrarily by themanufacturer from which horizontal distancesare measured for balance purposes. It may be

the nose of the airplane, the firewall or anyother convenient point .



28/59



29/59

BRAZO (ARM).

Es la distancia horizontal existente desde eldatum hasta un elemento (tripulante, pasaje,equipaje, etc..).



30/59



31/59



32/59

THE CENTRE OF GRAVITY (C.G.)

Is the point through which the weights of allthe various parts of an airplane pass. It is, ineffect, the imaginary point from which the

airplane could be suspended and remainbalanced. The C.G. can move within certainlimits without upsetting the balance of the

airplane. The distance between the forwardand aft C.G. limits is called the centre ofgravity range.



33/59

THE CENTRE OF GRAVITY (C.G.)

Is the point through which the weights of allthe various parts of an airplane pass. It is, ineffect, the imaginary point from which the

airplane could be suspended and remainbalanced. The C.G. can move within certainlimits without upsetting the balance of the

airplane. The distance between the forwardand aft C.G. limits is called the centre ofgravity range.



34/59

BRAZO DEL C.G. (C.G.ARM).

Distanciahorizontaldesde eldatum hastael centro de

gravedad.



35/59

MOMENTO (MOMENT).

La fuerza depalanca queejerce una

fuerza opeso. En estecaso, es el

producto delpeso de unelemento por

su brazo.ARTURO E RIVERA R. LIC IET 164 35


36/59

LIMITES DEL C.G. (C.G. LIMITS).

Establecen los lmites a la posicin del C.G.dentro de los cuales un avin con un pesodeterminado puede volar con seguridad. Se

suelen expresar en pulgadas contando a partirdel datum.



37/59

THE MOMENT ARM

is the horizontal distance in inches from thebalance datum line to the C.G. The distancefrom the balance datum line to any item, such

as a passenger, cargo, fuel tank, etc. is the armof that item.



38/59

THE BALANCE MOMENT OF THEAIRPLANE

is determined by multiplying the weight of theairplane by the moment arm of the airplane. It isexpressed in inch pounds.

The balance moment of any item is the weight of

that item multiplied by its distance from thebalance datum line.

It is, therefore, obvious that a heavy objectloaded in a rearward position will have a much

greater balance moment than the same objectloaded in a position nearer to the balance datumline.



39/59

THE MOMENT INDEX

is the balance moment of any item or of thetotal airplane divided by a constant such as100, 1000, or 10,000. It is used to simplify

computations of weight and balanceespecially on large airplanes where heavyitems and long arms result in large

unmanageable numbers.



40/59

If loads are forward of the balance datum linetheir moment arms are usually considerednegative (-). Loads behind the balance datum

line are considered positive (+)*. The totalbalance moment is the algebraic sum of thebalance moments of the airplane and each

item composing the disposable load.



41/59

In many cases the positive (+) sign is omitted, but thenegative (-) sign is always shown. To simplify matters, bothare included in our example

The C.G. is found by dividing the total balance moment (ininch-pounds) by the total weight (in lb.) and is expressed ininches forward (-) or aft (+) of the balance datum line.

The centre of gravity range is usually expressed in inchesfrom the balance datum line (i.e. +39.5" to +45.8"). In someairplanes, it may be expressed as a percentage of the meanaerodynamic chord (25% to 35%). The MAC is the meanaerodynamic chord of the wing.



42/59



43/59

TO CALCULATE THE POSITION OF THEC.G. IN PERCENT OF MAC.

Let us assume that the weight and balance calculationshave found the C.G. to be 66 inches aft of the balancedatum line and the leading edge of the MAC to be 55inches aft of the same reference .

The C.G. will, therefore, lie 11 inches aft of the leadingedge of the MAC. If the MAC is 40 inches in length, theposition of the C.G. will be at a position (11 ~ 40) 27%of the MAC.

If the calculated C.G. position is within therecommended range (for example, 25% to 35%), theairplane is properly loaded.



44/59

FINDING BALANCE BY

COMPUTATION METHOD

For this example, an airplane with a basicweight of 1575 lb. and an authorized grossweight of 2600 lb. has been selected. The

balance datum line for the airplane, selectedby the manufacturer, is the firewall. Therecommended C.G. limits are 35.5" to 44.8".



45/59

FINDING BALANCE BY COMPUTATION

METHOD List in table form the airplane (basic weight),

pilot, passengers, fuel, oil, baggage, cargo, etc.,their respective weights and arms. Calculate thebalance moment of each. Total the weights. Total

the balance moments. Divide the total balancemoment by the total weight to find the momentarm (i.e. the position of the C.G.).

(Note: In this example, the oil is listed as a

separate item and the balance datum line is thefirewall in order to give an example of a negativemoment arm.)



46/59

The moment arm for this loading of theairplane is 42.52" (110,270-- 2593). The totalweight (2593 lb.) of the loaded airplane is less

than the authorized gross weight (2600 lb.).The moment arm falls within the C.G. range(35.5" to 44.8"). The airplane is, therefore,

properly loaded.



47/59

ITEM WEIGHT LBS ITEM MOMENT

ARM INCHES

BALANCE MOMENT

INCH-LBS

Basic Airplane 1575 +36 +56.700

Pilot 165 +37 +6,105

Passenger (front seat) 143 +37 +5,291

Passenger (rear seat) 165 +72 +11,880

Child (rear seat) 77 +72 +5,544

Baggage 90 +98 +8,820

Fuel 360 +45 +16,200

Oil 18 -15 -270

TOTAL 2593 42,53 110,270



48/59



49/59



50/59



51/59

CALCULO DEL CG

PESO BRAZO MOMENTO

PESO BASICO VACIO 1169 732. 85570

PILOTOS Y PASAJEROS 340 85.5 29070

COMBUSTIBLE 61 75.4 4599

EQUIPAJE 100 115.0 11500TOTAL 1670 78.3 130739



52/59

PROCEDIMIENTO TABULAR

1. Anotar en la primera columna los pesos de cada uno de los elementos

2. En la segunda columna la distancia de los elementos (arm) al datum.

3. En la tercera el momento de cada fila, multiplicando el peso (col.1) por el

brazo (col.2).

4. Sumar la primera columna (peso total) y la tercera (momento total).5. Dividiendo el momento total de la columna tercera por el peso total de

la columna primera, resulta el brazo (arm) del centro de gravedad

6. Con este peso y esta distribucin, se obtiene la posicin del c.g. desde el

datum.

7. Anotar enla fila de totales, en la columna 2.8. Verificar que el peso total (columna 1) y la posicin del c.g. (columna 2)

estn dentro de los lmites aprobados.



53/59



54/59



55/59

PROCEDIMIENTO CON GRFICAS

Sumar los pesos de todos los elementos. Esto nos da el peso total quedebemos comprobar si est en lmites.

En el grfico de carga determinar el momento de todos y cada uno de loselementos transportados en el aeroplano (la interseccin del peso en eleje Y con la lnea transversal correspondiente al elemento se proyecta

sobre el eje X Sumar todos los momentos obtenidos al momento del peso en vaco

especificado por el fabricante.

Dividir el momento total por el peso total

El resultado es la situacin del c.g. desde el datum.

Localizar en el grfico de la derecha el punto de interseccin del peso total(eje Y) con el resultado obtenido en el eje X.

Si est dentro del contorno marcado en rojo, el avin tiene el c.g. actualdentro de lmites.



56/59

FLOAT BUOYANCY:



57/59

FLOAT BUOYANCY:

The maximum permissible gross weight of aseaplane is governed by the buoyancy of thefloats. The buoyancy of a seaplane float is

equal to the weight of water displaced by theimmersed part of the float. This is equal to theweight the float will support without sinking

beyond a predetermined level (draught line).



58/59

FLOAT BUOYANCY:



59/59

FLOAT BUOYANCY:

The buoyancy of a seaplane float is designated by itsmodel number. A 4580 float has a buoyancy of 4580 lb.A seaplane fitted with a pair of 4580 floats has abuoyancy of 9160 lbs.

Regulations require an 80% reserve float buoyancy. Thefloats must, therefore, have a buoyancy equal to 180%of the weight of the airplane.

To find the maximum gross weight of a seaplane fitted

with, say 7170 model floats, multiply the floatbuoyancy by 2 and divide by 1.8 (7170 x 2)/1.8 = 7966lb.

Calculo de Peso y Balance

Documents

Transcript of Calculo de Peso y Balance