12.108. Weight and Loading

12.108.2(c) . use index units. 

When calculating the weight and balance of an aircraft the moments are often large numbers
The size of the number is reduced by dividing by 10,000
An index unit is 10,000kg-mm

12.108.2(b) . use a typical loading graph to determine C of G position; 

Determine the take-off weight and moment for the loaded aircraft
To find the moments for each station, enter with the weight on the vertical axis.
Read horizontally across to the sloping line marked “Fuel AVGAS” then move vertically up to read off the moment
Repeat the process for each station listed in the loading details sheet
When complete add up the two columns to find the take-off weight and moment
Check to ensure that the weight and CG are within limits
Enter the CG Moment Envelope graph from the R and from the top..
The CG is where the two lines intersect

12.108.2(a) . calculate the C of G position; 

1. List all weights and their arms
2. Multiply the weights by their arms to obtain individual moments
3. Add all the weights to obtain the gross
4. Add the moments to obtain total moment
5. Divide the total momenjt by total gross weight to obtain the CG position

12.108.2. Given a basic aircraft load sheet/data, demonstrate the ability to:

12.106. Definitions, Terminology and AbbreviationsSub Topic Syllabus Item 

12.106.2(j) . maximum certified take-off weight (MCTOW). 

MCTOW is the maximum certificated gross weight permitted to take off

12.106.2(i) . gross weight (AUW); 

This is the total weight of the aircraft and its contents at any particular time’
Equals basic weight plus pilot plus passengers, baggage and cargo, plus ballast plus fuel load

12.106.2(h) . zero fuel weight (ZFW); 

This is the gross weight of the aircraft excluding the usuable fuel in the wing fuel tanks
– includes the pilot, payload and ballast but none of the usable fuel
– usable fuel is not included / unusable fuel is included

12.106.2(g) . basic aircraft empty weight (standard empty weight); 

This includes the weight of the airframe and engine, fixed equipment, unuseable fuel, full oil and other items necessary for all flights

Does not include passengers and freight – pilot or payload