mass & Balance - 1

Conversion: Inches to centimeters

Multiply by $2.54$

Conversion: Centimeters to inches

Divide by $2.54$

Conversion: Feet to inches

Multiply by $12$

Conversion: Inches to feet

Divide by $12$

Conversion: Meters to feet

Multiply by $3.28$

Conversion: Feet to meters

Divide by $3.28$

Conversion: Nautical miles (NM) to meters

Multiply by $1852$

Conversion: Meters to nautical miles (NM)

Divide by $1852$

Conversion: Kilograms to pounds (lb)

Multiply by $2.205$

Conversion: Pounds (lb) to kilograms

Divide by $2.205$

Conversion: Imperial gallons to pounds (lb)

Multiply by $(10 \times \text{SG})$

Conversion: Pounds (lb) to Imperial gallons

Divide by $(10 \times \text{SG})$

Conversion: US gallons to liters

Multiply by $3.785$

Conversion: Liters to US gallons

Divide by $3.785$

Conversion: Imperial gallons to liters

Multiply by $4.546$

Conversion: Liters to Imperial gallons

Divide by $4.546$

Conversion: Imperial gallons to US gallons

Multiply by $1.2$

Conversion: US gallons to Imperial gallons

Divide by $1.2$

Formula relating mass, volume, and specific gravity (SG)

$$\text{Mass} = \text{Volume} \times \text{SG}$$

Specific gravity (SG) of pure water at $4^\circ\text{C}$

$$1.0$$

Formula for weight in terms of mass and gravitational acceleration

$$\text{Weight} = \text{Mass} \times g$$

Standard acceleration due to gravity ($g$)

$$9.81\,\text{m/s}^2$$

Mnemonic for All-Up Mass (AUM) structure

Big Vans Travel Fast Down Under in OZ

Basic Empty Mass (BEM)

The mass of an aircraft including unusable fuel and permanent equipment, excluding crew, payload, and usable fuel.

Variable Load (VL)

The mass of the flight crew, cabin crew, their baggage, and required operational equipment.

Traffic Load (TL)

The total mass of revenue and non-revenue passengers, baggage, and cargo.

Dry Operating Mass (DOM)

$$\text{BEM} + \text{VL}$$

Useful Load

$$\text{TL} + \text{Fuel}$$

Operating Mass (OM)

$$\text{DOM} + \text{Fuel}$$

Zero Fuel Mass (ZFM)

$$\text{DOM} + \text{TL}$$

Ramp Mass (RM)

The total mass of the aircraft prior to engine start and taxi; equivalent to Maximum AUM.

Ramp Fuel (RF)

$$\text{Taxi Fuel} + \text{TOF}$$

Take-Off Mass (TOM) formula

$$\text{TOM} = \text{RM} - \text{Taxi Fuel}$$

Take-Off Fuel (TOF) formula

$$\text{TOF} = \text{RF} - \text{Taxi Fuel}$$

Landing Mass (LM)

The mass of the aircraft upon landing, equal to Take-Off Mass minus fuel burned during flight.

Four primary structural mass limits

MRM (Maximum Ramp Mass), MSTOM (Maximum Structural Take-Off Mass), MZFM (Maximum Zero Fuel Mass), and MSLM (Maximum Structural Landing Mass).

Performance mass limits

PLTOM (Performance Limited Take-Off Mass) and PLLM (Performance Limited Landing Mass).

Regulated Take-Off Mass (RTOM)

The lowest and most restrictive limit between MSTOM and PLTOM.

Regulated Landing Mass (RLM)

The lowest and most restrictive limit between MSLM and PLLM.

ATOM calculation Method 1

$$\text{RTOM}$$

ATOM calculation Method 2

$$\text{RLM} + \text{Trip Fuel}$$

ATOM calculation Method 3

$$\text{MZFM} + \text{TOF}$$

Criterion for determining Allowed Take-Off Mass (ATOM)

The most restrictive limit, which corresponds to the lowest calculated value among the three methods.