MASS (WEIGHT) & BALANCE

MASS (WEIGHT) & BALANCE LECTURE 2 COMPOSITION OF AIRCRAFT WEIGHT MBC 3204 - SIR ARIFF AMC

WEIGHT DEFINITION • Weight is the force that results from the acceleration by gravity on the mass of an object. W = mg • In modern scientific usage, weight and mass are fundamentally different quantities. • Mass is an intrinsic property of matter, whereas weight is a force that results from the action of gravity on matter: it measures how strongly the force of gravity pulls on that matter. MBC 3204 - SIR ARIFF AMC

Continue.. • However, in most practical everyday situations the word "weight" is used when, strictly, "mass" is meant. • For example, most people would say that an object "weighs one kilogram", even though the kilogram is a unit of mass. weight will give us more stability MBC 3204 - SIR ARIFF AMC

Therefore in our discussion later, please KNOW that WEIGHT is a MASS of aircraft. MBC 3204 - SIR ARIFF AMC

Continue.. • The lift generated by the airfoils of the aircraft must be able to overcome the weight. Why? • Less weight will give us better performance • More weight will give us more stability • Excessive weight will cause the aircraft crash. MBC 3204 - SIR ARIFF AMC

TIME TO THINK!! Do you agree with all the facts given?? Give any examples to proves this fact. You may relate it with anything in your life. Not necessarily related with aviation. THINK OUT OF THE BOX! MBC 3204 - SIR ARIFF AMC

WEIGHT CONTROL • When an aircraft is designed, it is made as light as the required structural strength will allow, and the wings or rotorsare designed to support the maximum allowable weight. • Weight is a critical factor for an aircraft. • Excessive weight reduces the efficiency of an aircraft and the safety margin available if an emergency condition should arise. MBC 3204 - SIR ARIFF AMC

COMPOSITION OF AIRCRAFT WEIGHT MBC 3204 - SIR ARIFF AMC

OVERVIEW • All aircraft have a specified maximum mass. • This limit must be respected, whether the aircraft is a micro-light or a Boeing 747 or an Airbus A380. • Attempting to fly an overloaded/overweight aircraft can cause various effects (Performance and stability control) MBC 3204 - SIR ARIFF AMC

To ensure aircraft can fly safely, limitation are set by the design engineer. • Maximum Take-Off Weight (MTOW): The maximum permissible weight to conduct a takeoff. • Maximum Landing Weight (MLW): The maximum permissible weight to conduct a landing. • Maximum Zero Fuel Weight (MZFW): The maximum weight of an aircraft which its structural limits would allow. MBC 3204 - SIR ARIFF AMC

Maximum Takeoff Weight (MTOW) • MTOW of an aircraft is the maximum weight at which the pilot of the aircraft is allowed to attempt to take off. • It is the heaviest weight which should be limited in order to ensure the aircraft can fly safely during take-off. • At its MTOW an aircraft complies with all the structural and performance requirements. • The MTOW of an aircraft is fixed. MBC 3204 - SIR ARIFF AMC

Continue.. • It does not vary with altitude or air temperature or the length of the runway to be used for takeoff or landing. • MTOW is usually specified in units of kilograms or pounds. • What is the difference between kilogram (kg) and pound (lb)?? MBC 3204 - SIR ARIFF AMC

Maximum Landing Weight (MLW) • The maximum permissible weight to conduct a landing. • What will happen if the aircraft weight during landing is greater than MLW? What is the possibility? MBC 3204 - SIR ARIFF AMC

Maximum Zero-Fuel Weight (MZFW) • The Zero Fuel Weight (ZFW) of an airplane is the total weight of the airplane and all its contents, minus the total weight of the fuel on board. • When an airplane is being loaded with crew, passengers, baggage and freight it is most important to ensure that the Zero Fuel Weight does not exceed the Maximum Zero Fuel Weight. • Designers of airplanes can optimize the MTOW and prevent overloading in the fuselage by specifying a MZFW. This is usually done for large airplanes. • Most small airplanes do not have a MZFW specified among their limitations. MBC 3204 - SIR ARIFF AMC

Example.. • For example, if an airplane is flying at a weight of 5,000 lb and the weight of fuel on board is 500 lb, the Zero Fuel Weight is 4,500 lb. • Some time later, after 100 lb of fuel has been consumed by the engines, the total weight of the airplane is 4,900 lb and the weight of fuel is 400 lb. • What is the Zero Fuel Weight? MBC 3204 - SIR ARIFF AMC

All Up Weight (AUW) • The total weight of the aircraft including of all items at any specific time. • During take off All up weight (AUW) must not exceed the Maximum Take Off Weight (MTOW) For Take-Off: AUW/TOW ≤ MTOW MBC 3204 - SIR ARIFF AMC

Continue.. • During landing All up weight (AUW) must not exceed the Maximum Landing Weight (MLW) For Landing: AUW/LW ≤ MLW • Total ZFW also must not exceed the Maximum Zero Fuel Weight (MZFW). ZFW ≤ MZFW MBC 3204 - SIR ARIFF AMC

IMPORTANT For Take-Off: AUW/TOW ≤ MTOW For Landing: AUW/LW ≤ MLW MBC 3204 - SIR ARIFF AMC

All Up Weight (AUW) Where, PAYLOAD = Passengers & Cargo FUEL = Flight Fuel + Reserve Fuel DOW = Dry Operating Weight DOW also known as Aircraft Prepared for Service (APS) AUW = DOW + PAYLOAD + FUEL MBC 3204 - SIR ARIFF AMC

Dry Operating Weight (DOW) @ APS • Basic Weight + Crew & Baggage Basic Weight • It consists of Empty Weight +Basic Equipment Weight. Empty Weight • Weight of airframe, engines and standard structures. Basic Equipment Weight • Weight of common installations inside the airplane. MBC 3204 - SIR ARIFF AMC

Payload • The weight of all persons and items of load carried in an aircraft for which a fare or charge is being paid. • PAYLOAD = Passengers + Cargo MBC 3204 - SIR ARIFF AMC

Fuel • FUEL = Flight Fuel + Reserve Fuel • Flight Fuel = It is the weight of the fuel required for and burnt during a flight. • With the given flight distance and mean airspeed , Flight Fuel can be calculated as follows: Flight Fuel = Fuel Flow × Flight Time • Where, Flight time= Distance / Mean Airspeed MBC 3204 - SIR ARIFF AMC

All Up Weight (AUW) However, AUW is not same during Take-off and landing. Why? During TAKE-OFF: AUW during Take-Off=DOW + PAYLOAD + (Flight Fuel + Reserve Fuel) During LANDING: AUW during Landing =DOW + PAYLOAD + Reserve Fuel Note that, as a flight progresses , flight fuel is consumed and finished. MBC 3204 - SIR ARIFF AMC

RELATIONSHOP BETWEEN WEIGHT TERMINOLOGY MBC 3204 - SIR ARIFF AMC

Basic Aircraft + Basic Equipment Basic Weight DOW or APS Weight Crew, Crew Baggage + Equipment Variable Load Take-off Weight Cargo / Freight Payload Passengers + Baggage Disposable load Fuel MBC 3204 - SIR ARIFF AMC

Exercise on Definition of Weight State true of false. If false, correct it. Disposable load = usable fuel + payload Payload = Passenger Load + Cargo Load Variable Load = Crew load + equipment load APS Weight = Dry operating Weight (DOW) APS Weight = AUW – Disposable Load APS Weight = ZFW – Payload Basic Weight + Variable Load + Disposable load = AUW ZFW – Payload = DOW Basic Weight = Basic equipment weight + Airframe + engine + unusable fuel. This course is easy! MBC 3204 - SIR ARIFF AMC

MASS (WEIGHT) & BALANCE