1.1 Block Fuel (Ramp Fuel)

Total fuel required for the flight including safety margins.

Includes:

• Taxi Fuel
• Trip Fuel
• Contingency Fuel
• Alternate Fuel
• Final Reserve Fuel
• Additional Fuel
• Extra Fuel

1.2 Taxi Fuel

Fuel used before take-off:

• APU consumption
• Engine start
• Taxi

1.3 Take-off Fuel

Fuel available at brake release.

Formula:

Take-off Fuel = Block Fuel – Taxi Fuel

1.4 Trip Fuel

Fuel from:

• Brake release Take-off, climb, cruise, descent, approach, landing→ Destination touchdown

Includes:

• Take-off, climb, cruise, descent, approach, landing

1.5 Contingency Fuel

Fuel for unforeseen conditions:

• Weather deviations
• Holding delays

Standard:

Minimum = 5% of Trip Fuel or 5 minutes whichever is greater.

1.6 Alternate Fuel

Fuel required:

• Missed approach → Alternate aerodrome landing

1.7 Final Reserve Fuel

Minimum mandatory fuel:

• Jet: 30 minutes (holding at 1500 ft above alternate)
• Piston: 45 minutes
• No alternate: Minimum 60 minutes

1.8 Additional Fuel

Required for:

• ETOPS
• System failures
• Remote destinations

1.9 Extra Fuel

Added at Captain’s discretion

1.10 Landing Fuel

Fuel remaining at touchdown

Formula:

Landing Fuel = Take-off Fuel – Trip Fuel

2.1 Empty Mass

Aircraft as delivered (includes undrainable oil and fuel)

2.2 Basic Empty Mass (BEM)

Empty Mass + permanent equipment:

• Manuals, charts
• Oil, unusable fuel
• Safety equipment

2.3 Dry Operating Mass (DOM)

BEM + operational items (no fuel, no payload)

Includes:

• Crew & baggage
• Catering
• Water & chemicals
• any standard operational equipment for that mission / flight.

2.4 Traffic Load (Payload)

Passengers + baggage + cargo + any non-revenue load if available.

2.5 Useful Load

Useful Load = Traffic Load + Take-off Fuel

2.6 Operating Mass (OM)

OM = DOM + Fuel

2.7 Zero Fuel Mass (ZFM)

ZFM = DOM + Traffic Load

2.8 Maximum Zero Fuel Mass (MZFM)

• Structural limitation, must not exceed.
• Based on wing root strength

2.9 Take-off Mass (TOM)

Total aircraft mass at start of take-off

3.1 Structural Limits

• MSTOM → Max structural take-off mass
• MSLM → Max structural landing mass

3.2 Performance Limits

• PLTOM → Runway/conditions limited take-off mass
• PLLM → Landing performance limited mass

3.3 Regulated Mass

RTOM = Lower of (MSTOM, PLTOM)
RLM  = Lower of (MSLM, PLLM)

3.4 Taxi / Ramp Mass

Ramp Mass – Taxi Fuel = Take-off Mass

3.5 Landing Mass

Landing Mass = Take-off Mass – Trip Fuel

Step 1: Determine Take-off Mass

TOM = Ramp Mass – Taxi Fuel
TOM = Landing Mass + Trip Fuel
TOM = ZFM + Take-off Fuel
TOM = DOM + Traffic Load + Take-off Fuel

Step 2: Calculate Payload

Payload = TOM – (DOM + Take-off Fuel)

Step 3: Useful Load

Useful Load = Payload + Take-off Fuel

Aircraft is ALWAYS limited by:

• Regulated Take-off Mass (RTOM)
• Regulated Landing Mass (RLM)
• Maximum Zero Fuel Mass (MZFM)

Standard Weights

• Flight crew: 85 kg
• Cabin crew: 75 kg
• Child: 35 kg

Mass & Balance

• Index = Moment ÷ Constant
• CG obtained from weighing schedule

Fuel Flow

Taxi → Trip → Contingency → Alternate → Final Reserve → Additional → Extra

Mass Build-up

Empty → BEM → DOM → ZFM → TOM