Professional Aircraft Loading & Center of Gravity Calculator
Aircraft Weight & Balance Calculator
Enter your aircraft's loading data to verify safety limits.
Standard weight of the aircraft.
Please enter a positive number.
Distance from datum line.
Total weight of front seat occupants.
Fixed station arm.
Total weight of rear seat occupants.
Fixed station arm.
Avgas (6 lbs/gal).
Fixed station arm.
Max 120 lbs recommended.
Fixed station arm.
Calculated Center of Gravity (CG)
0.0 in
Within Limits
Total Gross Weight
0 lbs
Total Moment
0 lb-in
Useful Load
0 lbs
Formula: CG = Total Moment / Total Weight
Item
Weight (lbs)
Arm (in)
Moment (lb-in)
■ Safe Envelope
● Your Load
What is Weight and Balance Calculation Tutorial?
A weight and balance calculation tutorial is an essential educational resource for pilots, flight dispatchers, and aviation students. It explains the process of determining if an aircraft is loaded within its manufacturer-specified limits before takeoff. Proper loading ensures the aircraft's center of gravity (CG) falls within the safe envelope, which is critical for stability, controllability, and performance.
Understanding weight and balance is not optional; it is a regulatory requirement. Whether you are flying a small Cessna 172 or a large commercial airliner, the physics remain the same. This guide breaks down the complex mathematics into simple steps, helping you ensure every flight is safe and legal.
Weight and Balance Formula and Mathematical Explanation
The core concept of any weight and balance calculation tutorial relies on the principle of moments. Think of the aircraft as a seesaw. The balance point is the Center of Gravity (CG). To find it, we use the following fundamental formulas:
1. Moment = Weight × Arm 2. Total Moment = Sum of all individual moments 3. Center of Gravity (CG) = Total Moment / Total Weight
Variable Definitions
Variable
Meaning
Unit
Typical Range (GA)
Weight
The force exerted by gravity on an object.
lbs
1,500 – 3,000 lbs
Arm
Horizontal distance from the reference datum line.
inches
30 – 100 inches
Moment
The rotational force created by a weight at a distance.
lb-in
50,000 – 150,000
Datum
An imaginary vertical plane from which arms are measured.
N/A
Usually firewall or nose
Practical Examples (Real-World Use Cases)
Example 1: The Solo Training Flight
Imagine a student pilot flying a standard trainer aircraft. The Basic Empty Weight (BEW) is 1,650 lbs with an arm of 39.0 inches. The pilot weighs 180 lbs (Arm: 37.0). The fuel tanks are full with 50 gallons (300 lbs, Arm: 48.0).
BEW Moment: 1,650 × 39.0 = 64,350 lb-in
Pilot Moment: 180 × 37.0 = 6,660 lb-in
Fuel Moment: 300 × 48.0 = 14,400 lb-in
Total Weight: 2,130 lbs
Total Moment: 85,410 lb-in
CG: 85,410 / 2,130 = 40.1 inches
This result implies the aircraft is well within the standard utility category limits.
Example 2: The Overloaded Family Trip
Now consider a scenario with a pilot (200 lbs), front passenger (190 lbs), two rear passengers (350 lbs combined), and 100 lbs of heavy luggage. If the pilot fails to perform a weight and balance calculation tutorial check, they might miss that the Center of Gravity has shifted aft to 47.8 inches—potentially beyond the rear limit. This creates a dangerous "tail-heavy" condition, leading to stall instability and difficulty recovering from spins.
How to Use This Weight and Balance Calculation Tutorial Tool
Our calculator simplifies the manual math. Follow these steps:
Enter Basic Empty Weight: Find this in Section 6 of your Pilot's Operating Handbook (POH).
Input Occupant Weights: Enter the weight for the pilot, front passenger, and rear passengers.
Add Fuel: Input the fuel in gallons. The calculator automatically converts this to pounds (assuming 6 lbs/gal for Avgas).
Add Baggage: Weigh your bags accurately. Guessing is a common error in weight and balance calculation tutorials.
Analyze Results: Check the "Calculated CG" and the chart. If the dot is inside the green polygon, you are within the safety envelope.
Key Factors That Affect Weight and Balance Results
Several variables impact your calculation. Understanding these is vital for any weight and balance calculation tutorial.
Fuel Burn: As you fly, you burn fuel. This reduces weight but also shifts the CG. A plane that is safe at takeoff might become unsafe before landing if the fuel tanks are located forward or aft of the CG.
Temperature (Density Altitude): While not changing the physical weight, high temperatures reduce aircraft performance, making a heavy aircraft feel even heavier and more sluggish.
Baggage Placement: Moving a 50lb bag from the rear cargo area to the back seat can significantly shift the moment without changing total weight.
Modifications: New avionics or propellers change the Basic Empty Weight. Always use the current weight and balance sheet.
Passenger Accuracy: Using "standard weights" (e.g., 170 lbs per person) can be dangerous. Actual scale weights are always preferred.
Zero Fuel Weight: Some aircraft have a maximum weight for the structure excluding fuel, to prevent wing bending stress.
Frequently Asked Questions (FAQ)
What happens if the CG is too far forward?
A forward CG increases longitudinal stability but causes higher stall speeds and makes it difficult to flare during landing, potentially causing a nose-wheel strike.
What happens if the CG is too far aft?
An aft CG is dangerous. It reduces stability, makes stall recovery difficult or impossible, and decreases control effectiveness.
Does fuel weight change with temperature?
Yes, slightly. Fuel expands in heat, changing its density. However, for most general aviation weight and balance calculation tutorials, 6 lbs/gallon is the standard constant.
Where is the reference datum located?
The manufacturer decides this. It is often the firewall, the tip of the propeller spinner, or a point in space ahead of the aircraft.
Can I exceed the Max Gross Weight if the CG is perfect?
No. Even if the balance is perfect, exceeding the Max Gross Weight compromises structural integrity and climb performance.
How often should I weigh my aircraft?
Commercial operators have specific schedules, but general aviation aircraft should be re-weighed after major modifications or painting.
What is "Useful Load"?
Useful load is the difference between Max Gross Weight and Basic Empty Weight. It represents the weight available for pilot, passengers, fuel, and bags.
Is this calculator legal for flight planning?
This tool is for educational purposes only. Always use the official POH and data specific to your individual aircraft tail number for actual flight operations.
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