report weight n balance

8/8/2019 Report Weight n Balance

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INTRODUCTION

As an aircraft maintenance technician we will often perform repairs or alternations

that change an aircrafts weight and balance. This in turn changes the way an aircrafts

weight must be effectively distributed, as well as its flight characteristics. Therefore, it is the

responsibility of the aircraft maintenance technician who makes a repair or alteration to

change the aircraft weight and balance paperwork. This paperwork must be reflecting the

new computations for weight and balance, and indicate the aircraft is safe to fly. This

information then allows the pilots to make an informed decision as to the airworthiness of the

aircraft.

The principles of weight and balance should have been understood by all pilots during

their initial training. It is clear that, afterwards, some forget, don't bother or are caught in 'traps'

There have been several fatal accidents to general aviation aircraft in which overloading, or out-

of-limits centre of gravity (cg), were contributory factors. An overloaded aircraft may fail to

become airborne, while out-of-limits centre of gravity seriously affects the stability and

controllability. Pilots must appreciate the effects of weight and balance on the performance and

handling of aircraft, particularly in combination with performance reducing factors, such as long

or wet grass, a 'tired' engine(s), severe or un-coordinated manoeuvres, turbulence, high ambient

temperatures and emergency situations.


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EQUIPMENT


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NO ITEM QUANTITY REMARKS

1 Light fixed-wing aircraft 01

2 Aircraft jack As required

3 Bottle jack As required

4 Jack adapter 03

5 Weighing scale 1 set

6 Chocks 06

7 Plum bob 02

8 Measuring tape 01

9 Spirit level 02

10 L Engineering square 01

11 Chalky line 01

12 Chalk 4 pieces

13 Tire inflator and gauge 01

14 Nitrogen gas bottle+ chuck key 01

15 Electrical wire cable/connector 01

AIRCRAFT DEFUELING QUANTITY REMARKS

1 Empty container (cleaned) As required

2 Filter+ funnel 1 each

3 Step (portable) 02

4 Ground bonding wire 02

5 Rags As required

6 Fire extinguisher(CO2) 01

7 Hand tools As required

AIRCRAFT WASHING

1 Soap cleaner/ detergent As required Approved type

2 Water spray gun 1 set

3 Rags and sponge As required

4 Masking tape 2rolls

5 Cleaning solvents As required Approved type


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Prepare Aircraft for Weighing

Drain the fuel system until the quantity indication reads zero, or empty, with the

aircraft in a level attitude. If any fuel is left in the tanks, the aircraft will weigh more, and all

later calculations for useful load and balance will be affected. Only trapped or unusable fuel

(residual fuel) is considered part of the aircraft empty weight. Fuel tank caps should be on the

tanks or placed as close as possible to their correct locations, so that the weight distribution

will be correct.

In special cases, the aircraft may be weighed with the fuel tanks full, provided a

means of determining the exact weight of the fuel is available. Consult the aircraft

manufacturer's instructions to determine whether a particular model aircraft should be

weighed with full fuel or with the fuel drained.

If possible, drain all engine oil from the oil tanks. The system should be drained with

all drain valves open. Under these conditions, the amount of oil remaining in the oil tank,

lines, and engine is termed residual oil and is included in the empty weight. If impractical to

drain, the oil tanks should be completely filled.

The position of such items as spoilers, slats, flaps, and helicopter rotor systems is an

important factor when weighing an aircraft. Always refer to the manufacturer's instructions

for the proper position of these items.

Unless otherwise noted in the Aircraft Specifications or manufacturer's instructions,

hydraulic reservoirs and systems should be filled; drinking and washing water reservoirs and

lavatory tanks should be drained; and constant speed drive oil tanks should be filled.


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Inspect the aircraft to see that all items included in the certificated empty weight are

installed in the proper location. Remove items that are not regularly carried in flight. Also

look in the baggage compartments to make sure they are empty. Replace all inspection plates,

oil and fuel tank caps, junction box covers, cowling, doors, emergency exits, and other parts

that have been removed. All doors, windows, and sliding canopies should be in their normal

flight position. Remove excessive dirt, oil, grease, and moisture from the aircraft.

Properly calibrate, zero, and use the weighing scales in accordance with the

manufacturer's instructions.

Some aircraft are not weighed with the wheels on the scales, but are weighed with the

scales placed either at the jacking points or at special weighing points. Regardless of what

provisions are made for placing the aircraft on the scales or jacks, be careful to prevent it

from falling or rolling off, thereby damaging the aircraft and equipment. When weighing an

aircraft with the wheels placed on the scales, release the brakes to reduce the possibility of

incorrect readings caused by side loads on the scales.

All aircraft have leveling points or lugs, and care must be taken to level the aircraft,

especially along the longitudinal axis. With light, fixed wing airplanes, the lateral level is not

as critical as it is with heavier airplanes. However, a reasonable effort should be made to level

the light airplanes around the lateral axis. Accuracy in leveling all aircraft longitudinally

cannot be overemphasized.


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PROCEDURE

WEIGHING USING PLATFORM SCALES AND RAMPS

NOTE: All safety precautions and procedures must be observed

Step 1: Remove all items that do not have a fixed location in the aircraft(e.g

Tools,books,manuals,headset etc)

Step 2: Level aircraft using procedures in the Service Manual and chock the main

wheels.

Step 3: Drop plum-bob from the center of axles and mark location on the floor.

Step 4: Remove the chocks and the plum-bob and move the aircraft as necessary to

gain access to the chalk marks.

Step 5: Make a chalk line between the main wheel axle marks using a chalky line

/string

Step 6: Mark the midway point between the main wheels.Extend a line from this point

to center line of the nose wheel.Extend the firewall mark to intersect this line.Use a

carpenters quare , if necessary.

Step 7: Measure from the firewall mark (datum) to the nose wheel CL (center line).

Make another measurement from the datum to the line drawn between the main

wheels.Record the measurements for the later calculations.


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Step 8: Zero scales, weigh and record applicable tare weight the weight and balance

form.

Step 9: Position personnel to roll the aircraft to roll aircraft on to the scales.

Step 10: Roll aircraft on scales,making sure the wheels are centered on the scales.

Step 11: Level aircraft using spirit level on the top of the tail cone.Add or remove air

from the nose strut to attain level position longitudinally.

Step 12: Place spirit level on the seat rail to check level laterally.

Step 13: Record scale readings and remove the aircraft from scales.

Step 14: Go back to step 8 and repeat the procedure two more times so that three

weights are available for each wheel.Average the weights before entering them on the

weight and balance form.

Step 15: Make practice entries in the sample log book.

Step 16: Return the equipment and materials to original point.

Step 17: Check with instructor before going on the next project.


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AIRCRAFT WEIGHING PROCEDURES CHECKLIST

PREPARATION

1. Obtain all requireddata with regard to weighing TCDS etc

2. Check aircraft fuel.If it is not empty, drain the fuel / top up to the required

specification

3. Clean the aircraft / washing

Safety

Cover all static port and pitot tube before cleaning

Use only approved detergent/soap.

Use brushes and rags that are clean from dirt/ sand or FOD.

4. Make sure aircraft is in the closed hangar on level ground.

5. Check equipment list or ballast- refer TCDS

6. Inflate all tyres to the recommended operating pressure refer maintenance

manual

7. Place front seat in most forward position with seat back in most nearly vertical

position.

8. Check the aircraft date of registration refer TCDS Prior to 1 March 1978:

Drain oil &operating fluid.

9. Place control surfaces in neutral position.


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CALIBRATE THE WEIGHING SCALE

1. Zero out the reading on the scale refer to the manual

2. Weigh the chocks and record reading/ tare weight.

NOTE: Get Instructor approval


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JACK THE AIRCRAFT

1. Read aircraft manufacturer instruction prior to jacking.

*Rope off the jacking area/ nobody should in the aircraft.

2. Jack the aircraft up Get instructor

Use approved and appropriate jacks- check the load capacity.

Make sure there is no obstruction

Proper adapter or stress plate has been installed.

Jack the aircraft up simultaneously and very slowly.

Place on the nose or place support on the tail to prevent tipping.

3.Place the weighing scale under the nose and main gears safety

Chock the aircraft

Make the sure the brake is release

4.Jack the aircraft down safety

Make sure the there is no obstruction & placed the gears center of

the scale.

Jack the aircraft down simultaneously and very slowly.


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LEVEL THE AIRCRAFT

1. Read manufacturer instruction and TCDS.

2. Level the aircraft laterally using spirit level and adjusting the level condition

of the aircraft by deflating or inflating the struts/ tyres of the main landing

gears using nitrogen gas.- Get instructor Safety

Avoid any contact with aircraft.

Slowly adjusdting the regulator during charging the strut

and release the strut slowly.

3. Level the aircraft horizontally /longitudinally using spirit level condition of the

aircraft by deflating or inflating the oleo struts of the nose gear using nitrogen

gas Get instructor.Safety

Avoid any contact with the aircraft

Slowly adjusting the regulator during charging the strut

and release the strut slowly

4.Get the instructor approval


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READING WEIGHING SCALE

1. Read the weight shown on the scale for each gear. Get instructor.

Safety

Make sure the scale has been calibrated / zero.

Make sure the unit used or shown on the scale is correct (lbs/kg)

and get at least minimum of three readings to get the average.

Avoid any contact with the aircraft.

2. Deduct any tare weight, if applicable from each reading.

3. Record the value in the weight and balanced form.

4. Get instructor approval.


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MEASURING THE DATUM

1. Read TCDS the position of the datum.

2. Using the plum bob, chalk and measuring tape ,mark the datum and the

weighing points, using chalk line or chalky string Get instructor

3. Measure the distance in inches of the nose gear and both the main landing

gears from the datum.

4. Record the measurements



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HOUSE KEEPING/ TIDY UP

1. Remove the weighing scale from the aircraft Get instructor

2. Fill up the fuel / replenish the oil as per TCDS, inflate tyres.- Get instructor.

Safety

Used approved and correct type for fuel and oil.

Install bonding strip/ cable to prevent electrical- static build

up.

3. Clean the area

4. Return all the tools and equipments needed to be returned to the tool store.



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CALCULATION AND DATA ENTRY

1. Calculate the empty weight of the aircraft (EW) and empty weight center of

gravity (EWCG) and record in the weight and balance form.

2. Find the maximum gross weight of the aircraft and calculate the useful load

for the aircraft.Record it in weighing form G-11.

3. Sign the weighing form.

4. Record the latest weight and balance data in the aircraft log book and sample

of aircraft log sheet for project G-11.

5. Sign the aircraft log book and aircraft log sheet G-11.

6. Make a report of your result finding/conclusion.


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WEIGHING FORM

MAKE_____________MODEL_____CESSNA 152______SERIAL__________N_______

DATUM LOCATION:_____________________________________________

WEIGHING CONDITIONS:

Main weighing point is located (-_______forward) (+__46.5_____aft) of datum

Tail or nose weighing point is located (-_______forward) (+_______aft) of datum

Maximum allowable gross weight______________ Computed by:_________

Useful Load__________________ A&P Number:________

Date:_________________

__

AIRCRAFT WEIGHT AND BALANCE

Various terms are used in the discussion of the weight of an airplane. They are as follows

Weighing point Scale reading -Tare =Net weight X Arm =Moment

Left Main 470 lb 1.5 468.5 lb + 46.5 21785.25

Right Main 500 lb 1.5 498.5 lb +46.5 23180.25

Nose or Tail 260 lb 1.5 258.5 lb -13.9 -3593.15

Total as Weighed 1230 lb 1.5 1225.5 33.75 41372.35


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Standard Weight Empty: The weight of the airframe and engine with all standard equipment

installed. It also includes the unusable fuel and oil

Optional or Extra Equipment: Any and ail additional instruments, radio equipment, etc.,

installed but not included as standard equipment, the weight of which is added to the standard

weight empty to get the basic empty weight. It also includes fixed ballast, full engine coolant,

hydraulic and de-icing fluid.

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.

Useful load (or Disposable load): The difference between gross take-off weight and basic

weight empty. It is, in other words, the entire load which is removable, which is not

permanently part of the airplane. It includes the usable fuel, the pilot, crew, passengers,

baggage, freight, etc.

Payload: The load available as passengers, baggage, freight, etc., after the weight of pilot,

crew, usable fuel have been deducted from the useful load.

Operational Weight Empty: The basic empty weight of the airplane plus the weight of the

pilot. It excludes payload and usable fuel.

Usable Fuel: Fuel available for flight planning.

Unusable Fuel: Fuel remaining in the tanks after a run out test has been completed in

accordance with government regulations.


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Operational Gross Weight: The weight of the airplane loaded for take-off. It includes the

basic weight empty plus the useful load.

Maximum Gross Weight: The maximum permissible weight of the airplane.

Maximum Take-Off Weight: The maximum weight approved for the start of the take-off

run.

Maximum Ramp Weight: The maximum weight approved for ground maneuvering. It

includes the weight of fuel used for start, taxi and run up.

Zero Fuel Weight: The weight of the airplane exclusive of usable fuel.

Passenger Weights: Actual passenger weights must be used in computing the weight of an

airplane with limited seating capacity. Allowance must be made for heavy winter clothing

when such is worn. Winter clothing may add as much as 14 lbs to a person's basic weight;

summer clothing would add about 8 lbs. On larger airplanes with quite a number of passenger

seats and for which actual passenger weights would not be available, the following average

passenger weights may be used. The specified weights for males and females include an

allowance for 8 lbs of carry-on baggage.

AVGAS-6 lbs. per gallon

Turbine fuel-6.7 lbs. per gallon

Lubrication oil-7.5 lbs. per gallon


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Water-8.35 lbs. per gallon

Crew&Passengers-170 lbs. per person

CONCLUSION


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An aircraft must only be flown within certificated limits of weight and balance to ensure that

it remains controllable, performs adequately and is not overstressed and overall is SAFETY.

Weight and balance technology, like all other aspects of aviation industry, has become more

complex as the efficiency and capability of aircraft and engines have increased. Therefore,this requires all pilots and AMTs to understand weight and balance control and to operate and

maintain their aircraft so its weight and CG location are within the limitations established

when the aircraft was designed, manufactured, and certified by the FAA.

As a conclusion, the Cessna that we have weighed is airworthy. It is because the weight of

the aircraft does not exceed the maximum allowable weight and the center of gravity is

within a specified limit range. This data shows that the aircraft Cessna 152 is safety to fly.

PHOTO


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ATTACHMENT

CESSNA 152


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The Cessna 152 is an American two-seater plane, fixed tricycle gear, general aviation plane

used commonly for flight training, touring, and personal flying.

Role Multipurpose civil aircraft

Manufacturer Cessna

Introduced 1977

Produced 1977-1985

Number built 7,584

Developed from Cessna 150


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REFERENCE

1. Maintenance manual

2. Type Certificate Data Sheet (TCDS)

3. Jeppersen Genaral Textbook

4. Instructor leaflet


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WEIGHT AND BALANCE

G-11

PERFORM AIRCRAFT WEIGHING FOR CESSNA 152

Prepared By:

Numan bin faris

1 MANUFACTURING

53133210381

Lecturer: HJ . ABDUL RASHID B . HJ . MAHMOOD


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report weight n balance

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