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- Airplane weight and balance are essential for ensuring flight safety, as well as the stable and reliable performance of the aircraft.
- Airplane weight and balance are calculated by determining the total weight of the loaded aircraft and the location of its center of gravity by using the ‘arm’ and ‘moment’.
- The ‘arm’ is the horizontal distance from the datum to the center of gravity of an item and the ‘moment’ is the product of the weight of an item multiplied by its arm.
Airplane weight and balance are fundamental principles in aviation, which is why all pilots are extensively tested on this before they are licensed.
Airplane weight and balance are essential for ensuring flight safety and the reliable performance of the aircraft. These figures are calculated by determining the total weight of the loaded aircraft and the location of its center of gravity.
After extensively researching aviation curriculums, I have gathered enough information to create a guide for airplane weight and balance. My research has indicated that having a thorough understanding of airplane weight and balance is mandatory for ensuring safe aircraft performance.
What is Airplane Weight & Balance?
If you are just starting out as a pilot, one of the first things that you will be taught in flight school is airplane weight and balance. This is a key component of aviation fundamentals, which is why every pilot understands how to balance an aircraft according to FAA standards.
Let’s break down weight and balance as it pertains to aviation and airplanes specifically:
- Weight - total weight of the loaded aircraft
- Balance - location of the center of gravity (CG)
Every pre-flight checklist involves ensuring that the airplane’s weight is balanced so that performance is smooth and the aircraft is safe to operate.
Why is Airplane Weight & Balance Important?
The bottom line is that if the weight of the aircraft is overloaded and the center of gravity is off, then you run the risk of a crash. Each airplane is designed for a maximum weight capacity, which must be adhered to ensure the safety of all passengers.
Exceeding the manufacturer’s recommended weight will result in overloading and the aircraft will have performance issues. On the other hand, if the airplane is extremely overloaded, it will simply fail to take off at all.
With that said, in case you can take off with an overloaded plane, you also need to keep in mind that each runway is designed with a length intended for safe aircraft take-off and landing. Depending on how much extra weight is in the aircraft, it may not have enough airstrip to get off the ground in time - also resulting in a crash.
The center of gravity of the airplane is equally important in so many ways, as this affects stability. If the center of gravity is off, the flight will feel shaky and the pilot will have a harder time controlling the plane.
If the center of gravity is not balanced based on the recommendation of the manufacturer, the plane will be unstable. You may not be able to reach the ideal altitude for your flight and there will be a higher stall speed. This can result in unpredictable performance that greatly increases the likelihood of an incident.
Which Items are Weighed When Balancing an Airplane?
Precision is imperative in the aviation industry and the finest detail can impact the safety of a flight, which is why all items in an airplane are weighed. Each aircraft manufacturer will provide detailed information about their plane after testing it extensively for safety.
By combining the weight of the aircraft with the weight of every single item that is added onto the plane, pilots and airline companies can properly balance the aircraft to ensure that it is safe for take-off. After the total empty weight of the airplane has been calculated, the following items will be weighed:
- Other miscellaneous items
If you have ever been through an airport check-in counter and wondered why they have such strict policies for luggage weight, it is to guarantee that the aircraft is safe to operate by balancing its weight and center of gravity.
This is important for every flight, but especially smaller planes that are more sensitive to changes in weight. Light aircraft will have a more shaky response and will likely struggle to take off when overloaded.
Commercial airliners, on the other hand, may not be as sensitive to this - with most being designed to safely take off with more weight. Nonetheless, airplane weight and balance are strictly enforced by the FAA, which is why every plane adheres to these protocols.
How to Calculate Airplane Weight & Balance
Calculating airplane weight and balance requires basic physics and some high-school algebra, but it does need to be done correctly for safety to be ensured. It’s also important to understand that this needs to be done on a case-by-case basis.
Every aircraft is different - with weight and overall design varying greatly across the board. In addition, the cargo and items brought on board a plane may also be different, which is why you need to calculate this thoroughly before each flight.
The aircraft itself is usually the most straightforward to estimate. When a manufacturer releases a plane and gets approval from the FAA, it means that it has been tested thoroughly and the weight specifications will all be provided. This is how you calculate airplane weight and balance.
After the weight of the aircraft is determined, you need to figure out the weight of each item that will be on board the plane. As I already covered, the typical items are things like luggage, passengers, and fuel.
A detailed log of all items is reviewed as the plane is organized for accurate weight and balance allocation. However, we need to calculate the arm and moment to truly achieve accuracy before take-off.
Arm & Moment
The ‘arm’ is an official term classified by the FAA. The arm is measured by the distance from the datum to any object or component brought onto the airplane.
If an item is further toward the back of the aircraft it will have a much bigger effect on the plane’s center of gravity. The company that made the aircraft will provide you with this information for the immovable objects on board.
After you have calculated the arm of your aircraft, you will need to multiply it by each item that you have on board, which will give you your ‘moment’. The total moment is the weight of the aircraft multiplied by the distance between the center of gravity and the datum.
Once all moment figures have been calculated, divide this number by the total weight of the aircraft. This will give you the overall arm number, which is the center of gravity for the entire airplane.
How to Confirm that the Airplane Weight & Balance is Safe
Instead of figuring out if your aircraft weight and balance are safe when you are already in the air, this should always be confirmed before take-off. To ensure that airplanes are safe to fly, the aircraft manufacturer will give you all of the information that you need to double-check weight and balance before a flight.
Refer to the manufacturer’s recommendations and check to see if the weight and center of gravity figures are within limits. Remember, both the weight and center of gravity need to be calculated for this.
How to Fix Airplane Weight and Balance
Fixing an airplane’s weight and balance is not very difficult, but it will require you to make some calculations to ensure that everything is in order.
Naturally, given that adding too much weight to the aircraft is what tipped the scales, you need to do the opposite to fix the problem. Depending on the type of flight, as well as the cargo that you are hauling, the first thing to do is remove unnecessary items from the airplane.
This will most likely be cargo and luggage - with people and fuel usually taking priority to keep on board. You need to remove items based on their weight, which you will subtract from the amount that you overloaded until you have reached a safe figure.
Fixing the balance of an airplane can often be a lot simpler, as you do not necessarily need to remove any items from the aircraft. This can often be an issue if you have too much cargo stored in one part of the plane or if you have too many passengers sitting on one side of the aircraft. Simply moving the weight around to achieve a balanced center of gravity will fix the issue.
Factors that Affect Airplane Weight and Balance
Following the FAA’s recommendations for airplane weight and balance is essential for ensuring flight safety. There is a lot to take in when operating an aircraft, but there is a reason that weight and balance are one of the first things that you learn in flight school.
You need to follow this procedure for every aircraft that you operate and calculations need to be made separately for each flight given that the cargo weight will always change. With that said, there are some additional factors that you should keep in mind for airplane weight and balance.
Stay Below the Weight Recommendation
When you check the recommendations that an aircraft manufacturer details for weight and balance, you will notice that they provide a specific maximum weight. While the airplane was tested for maximum weight capacity, you should not push its limits.
It is always best to have less weight than what a manufacturer recommends so that the aircraft is not overstrained, as this is a standard safety precaution.
Air density plays a critical role in how well a plane performs. This is particularly important to keep in mind for the weight and balance of an aircraft.
If the air is less dense, there won’t be as much lift and it will be difficult for the aircraft to climb. This means that you need more runway space for when you land and take off. The reason that this is important is that the weight of the aircraft can affect how easy it is to get off the ground and land safely. In general, if you are not overloading the airplane, this should not have a big impact on performance and safety, but it certainly can if there is more weight that the aircraft can handle.
The smallest details can potentially have a big effect on flight performance and safety, which is why being precise is paramount. Making sure that the weight and balance of the aircraft are calculated before take-off is an essential practice that should be hard-wired in every pilot.
It’s important not to overlook even the slightest details when making these calculations. Novice pilots have made serious mistakes with this by doing something as simple as rounding their weight figures. Piloting an aircraft is a huge responsibility which is why you should cross your t’s and dot your i’s when calculating the weight and balance of an airplane.