Load Factors

Load Factors control how passenger counts and cargo weights are calculated when pilots dispatch flights. Rather than fixed values, load factors use statistical distributions to create realistic variation - some flights are nearly full, others have empty seats.

Accessing Load Factors

In Orwell, go to Payload → Load Factors. You need the Manage Load Factors permission.

Load Factor Types

Each load factor type applies to a specific capacity calculation. The applicable types depend on your fleet configuration.

Passenger (People)

Applies to: Passenger, Passenger & Freight, Passenger & Containers fleets

Determines how many passengers board the flight. The calculation uses the aircraft's passenger capacity (or fleet default if not overridden on the aircraft).

Example: Aircraft has 180 seats. Load factor generates 85%. Result: 153 passengers.

Passenger (Hold Luggage)

Applies to: Passenger, Passenger & Freight, Passenger & Containers fleets

Determines how many passengers have checked baggage. Unlike other load factors, this calculation is based on the passenger count, not aircraft capacity.

Example: 153 passengers boarded. Luggage load factor generates 60%. Result: 92 bags of hold luggage (not 108, which would be 60% of 180 seats).

This reflects reality - luggage correlates with passengers, not empty seats.

Cargo (Weight)

Applies to: Passenger & Freight, Cargo - Freight, Passenger & Containers, Cargo - Containers fleets

For non-container fleets (Passenger & Freight, Cargo - Freight): Determines how much cargo weight is loaded. Uses the aircraft's cargo capacity in kilograms.

Example: Aircraft has 5,000 kg cargo capacity. Load factor generates 70%. Result: 3,500 kg of cargo loaded.

For container fleets (Passenger & Containers, Cargo - Containers): Sets the maximum weight limit for container loading. Pilots can load containers up to this weight limit.

Example: Aircraft has 20,000 kg cargo capacity. Load factor generates 80%. Result: Pilots can load containers totalling up to 16,000 kg.

Cargo (Volume)

Applies to: Passenger & Containers, Cargo - Containers fleets only

Determines how many container units can be filled. Uses the aircraft's Container Units capacity (configured on the fleet or aircraft).

Example: Aircraft has 12 container units. Load factor generates 75%. Result: Pilots can load containers occupying up to 9 units.

Container Aircraft: Dual Limits

Container-capable aircraft are constrained by both Cargo (Weight) and Cargo (Volume) load factors. Pilots must stay within whichever limit is reached first.

Summary Table

Load Factor Type	Fleet Types	Based On	Controls
Passenger (People)	Pax, Pax & Freight, Pax & Containers	Aircraft seat capacity	Passengers boarded
Passenger (Hold Luggage)	Pax, Pax & Freight, Pax & Containers	Passenger count (not capacity)	Checked bags
Cargo (Weight)	Pax & Freight, Cargo - Freight	Aircraft cargo capacity	Cargo loaded
Cargo (Weight)	Pax & Containers, Cargo - Containers	Aircraft cargo capacity	Max container weight
Cargo (Volume)	Pax & Containers, Cargo - Containers	Aircraft container units	Max container units

Load Factor Settings

Field	Description
Name	Display name to identify this profile (e.g., "Peak Season", "Low Demand"). Not shown to pilots.
Min %	Minimum load percentage (0-100). Flights never load below this.
Max %	Maximum load percentage (1-100). Flights never exceed this.
Average %	Target average percentage. Use this OR Bias, not both.
Bias	Distribution skew (0.0-1.0). Values below 0.5 favour the minimum, above 0.5 favour the maximum.
Deviation	Spread of generated values (0-100). Higher values create more variation.
Set as Default	Makes this the fallback for routes/airports without a specific assignment. Only one default per type.
Enable Loaded Amount Editing	When enabled, pilots can manually adjust the generated values during dispatch.

Load Factor Calculator

Each load factor has a built-in calculator to preview how your settings will behave. Access it by clicking the Calculate button when viewing or editing a load factor.

The calculator lets you:

• Enter a capacity value (e.g., 180 passengers, 5000 kg cargo)

• Run multiple simulations to see the range of generated values

• Verify your min, max, average/bias, and deviation produce realistic results

• Fine-tune settings before assigning the load factor to routes or airports

This is much faster than dispatching test flights and gives you immediate feedback on how your statistical parameters translate to actual load values.

vAMSYS Defaults

When no custom load factor is assigned, vAMSYS uses these default values:

Setting	Value
Min	80%
Max	100%
Bias	0.9
Deviation	0.2

This default configuration generates high utilisation rates averaging approximately 97%. For more realistic variation, consider creating custom profiles with lower minimums.

Setting Your Own Defaults

You can override the vAMSYS defaults by creating your own load factors and marking them as default.

How Defaults Work

• One default per type - Each load factor type (Passenger, Passenger Luggage, Cargo Weight, Cargo Volume) can have exactly one default.

• Automatic switch - When you mark a load factor as default, any previous default of that type is automatically unmarked.

• Overrides vAMSYS defaults - Your custom default replaces the vAMSYS default for that type across your entire airline.

• Fallback behaviour - If you have no custom default for a type, the vAMSYS default (80-100%, bias 0.9) applies.

To set a default, edit the load factor and enable Set as Default. The load factor list shows a badge indicating which load factor is the current default for each type.

Assignment Priority

Load factors cascade from most specific to least specific:

1. Route - Load factors assigned to the specific route

2. Arrival Airport - Default load factors for the destination (set on the Airport's Load Management tab)

3. Airline Default - The load factor marked as default for each type

The system checks each level in order and uses the first load factor found for each type.

Assignment Strategy

Use Airline defaults for:

• Your baseline load expectations

• Types you don't need granular control over

Use Airport defaults for:

• Hubs with consistently high demand

• Regional airports with lower traffic

• Seasonal destinations

Use Route overrides for:

• Charter routes with specific load requirements

• Premium routes that are always full

• Training routes where you want specific loads

Example Setup

For a European carrier:

Level	Passenger LF	Purpose
Airline Default	Min 50%, Max 95%, Avg 75%	General baseline
London Heathrow (Arrival)	Min 70%, Max 100%, Avg 90%	High-demand hub
Seasonal Greek Islands (Route)	Min 85%, Max 100%, Avg 95%	Peak summer routes

Distribution Settings

Understanding the statistical parameters:

Min/Max Range

Sets the possible range. A route with Min 60% and Max 95% will never dispatch with less than 60% or more than 95% capacity.

Average vs Bias

Choose one approach - do not use both together:

Average - Specify a target average. Over many flights, loads will centre around this value.

Bias - Control the distribution shape:

• 0.0 = Most flights near minimum

• 0.5 = Even distribution across the range

• 1.0 = Most flights near maximum

The bias creates an implied average: Average = Min + ((Max - Min) × Bias)

Deviation

Controls spread around the average/bias point:

• Low deviation (0.1-0.2) clusters values tightly

• High deviation (0.5+) spreads values across the full min-max range

The system uses a bell curve (normal distribution) and clamps results to the min-max range.

How the Math Works

Load factors use the Box-Muller transform to generate normally distributed values:

1. Two random numbers generate a bell-curve offset

2. The offset is scaled by your deviation setting

3. The result is centred on your average or bias-implied average

4. Values outside min-max are clamped to the range

This creates realistic variation where most flights cluster around your target, with occasional high and low outliers.

Practical Use Cases

Seasonal Variation

Create profiles for different demand periods:

Profile	Min	Max	Avg	Use Case
Peak Season	75%	100%	92%	Summer holidays, Christmas
Shoulder	50%	90%	70%	Spring, autumn
Low Season	30%	75%	50%	Winter off-peak

Assign these at the route or airport level as seasons change.

Route Type Profiles

Different route types have different load characteristics:

Profile	Min	Max	Avg	Use Case
Business Shuttle	60%	95%	80%	Frequent city pairs, business travel
Holiday Charter	85%	100%	95%	Package holiday flights
Regional Commuter	40%	85%	60%	Smaller routes with variable demand
Cargo Trunk	70%	100%	90%	Major cargo hub connections
Cargo Feeder	30%	80%	55%	Regional cargo collection

Pilot Editing

The Enable Loaded Amount Editing setting controls whether pilots can adjust generated values:

Enable when:

• Hosting events where load matters

• Pilots need flexibility for special operations

• You trust pilots to make reasonable choices

Disable when:

• You want consistent, realistic operations

• Load data feeds into challenge events

• You're simulating real-world operational constraints

When enabled, pilots see editable fields for passengers, luggage, and cargo during dispatch. They can adjust up to the aircraft's maximum capacity.

Integration with Other Systems

SimBrief

Generated loads are sent to SimBrief for flight planning. The OFP reflects the actual passenger count, baggage weight, and cargo load - not theoretical maximums.

SimBrief may offload cargo and passengers to meet aircraft weight requirements - offloaded passengers or cargo will not be updated on vAMSYS.

PIREPs

Load data is recorded in the PIREP, showing what was carried on the flight.

Scoring

Load factors don't directly affect PIREP scoring, but realistic loads contribute to accurate fuel planning and weight management.

Setting Up Load Management

For a new Virtual Airline, follow this sequence:

1. Create default profiles - One per type with reasonable baseline values

2. Mark defaults - Ensure one default exists per type

3. Test with the calculator - Use the built-in calculator to simulate results before going live

4. Add variation - Create seasonal or route-specific profiles

5. Assign to airports - Set up hub and regional airport defaults

6. Override routes - Add route-specific profiles where needed

Start simple and add complexity as your operation grows.

Troubleshooting

Flights are always nearly full:

• Check your defaults - vAMSYS default is ~97% average

• Create profiles with lower min/average values

Loads seem random with no pattern:

• Check deviation isn't too high

• Verify average or bias is set correctly

Load factor not applying:

• Check assignment priority (route → airport → default)

• Ensure the load factor type matches what you're testing

Pilots can't edit loads:

• Check "Enable Loaded Amount Editing" on the applicable load factor

Container limits seem wrong:

• Cargo (Weight) and Cargo (Volume) both apply to container aircraft

• Check both load factor types

Tips

• Create scenario-based profiles - Name them by purpose ("Charter Full", "Regional Commuter", "Cargo Express")

• Use Arrival Airport defaults - Hub airports often have different demand patterns than outstations

• Remember luggage is passenger-based - A 50% luggage load factor on 80 passengers gives 40 bags, not 50% of aircraft capacity

• Use the calculator - Test your settings with the built-in calculator before assigning to routes

• Consider cargo volume separately - Container aircraft need cargo-volume load factors tuned to their ULD capacity

• Start with defaults - Get baseline working before adding complexity

• Document your profiles - Use clear names so staff understand which to assign

Related

• Load Factor Import/Export - Bulk load factor management

• Containers - Container types for cargo-volume calculations

• Airports - Set airport-level load factor defaults

• Fleet - Configure fleet types that determine which load factors apply