To fly safely, aircraft must be balanced and loaded correctly. Imagine if, before every flight, you had to weigh*everything*onboard. Fortunately, we don’t have to do this. Why? Because we use*standard weights*when calculatingaircraftweight and balance. Today we will talk you through how aircraft loads are calculated, explain the general concept, and discuss factors that affectaircraftweight and balance.

Let’s dive right in.

## Standard Weights for Aircraft Weight and Balance – Quick Reference Table

The weight of several things carried aboard the aircraft can be easily computed using standard weights. Below, you’ll find a quick reference table detailing standard weights used in aviation. You can use these to calculate the weight of fluids carried aboard the airplane: –

Type | Pounds Per USG (32°F) | Pounds Per USG (59°F) |

EXHAUST | 6.14 | 6.01 |

JET A | 6.75 | 6.68 |

JET A1 | 6.75 | 6.68 |

Water | 8.35 | 8.33 |

Oil | 7.5 | 7.43 |

### How to Calculate Aircraft Weights Using the Above Table

Calculating liquid weights is really simple. It involves a little basic math. All we need to do is multiply the total number of gallons on board the aircraft by the weight, considering the temperature.

So, using the above table, let’s assume we have loaded 50 gallons of avgas onto our airplane. It looks something like this: –

__Total Fuel Weight = Volume (in USG) x Weight Factor__

Total Fuel Weight = 50 x 6.01

Total Fuel Weight =**300lbs**

Simple, right?

### Why Do Different Liquids Weight Different Amounts?

Different liquids weigh different amounts based on their*density*.

It works using the following equation.

**Density = Mass / Volume**

Don’t worry. We won’t get too scientific.

Generally speaking, every liquid has a different number of molecules based on a given set volume. The more molecules, the more the liquid weighs. To put it in technical terms, heavier liquids have a higher density. This is called*specific gravity.*

And get this.

You might be surprised to learn that a set volume of fuel, oil, and even alcohol and milk, weigh*less*than the same volume of water.

Don’t believe us? Use the table above using our calculation formula for ten gallons of water and then compare it to ten gallons of oil!

### Why Do Standard Weights Include Temperature Data?

The eagle-eyed among you may have noticed that there are two columns, giving different values depending on temperature.

Why is this?

Well, to cut a long story short…

When calculating airplane mass and balance, we are primarily interested in*weight*, not*volume*. Unfortunately, a gallon is a measure of*volume*. ‘Volume’ is the total area a given fluid takes up in space.

Remember how we said fluids weigh different amounts based on their density?

Well, this density (the number of molecules in a given volume of fluid) changes based on the temperature of that fluid.

As a general rule, you need to remember this…

- The warmer a fluid, the less dense it will be.
- The colder a fluid, the denser it will be.

Why?

The volume of most fluids changes based on temperature. Avgas and Jet kerosene both*expand*as they get warmer.

Remember the above equation?

- Density = Mass / Volume

If the volume goes up, that means the mass is divided by a greater number, making the density*less*. While you may not think this is significant, a relatively minor temperature change can make all the difference. This is especially true when uplifting large volumes of liquids.

## The Effects of Weight and Balance on Aircraft Behavior – 10 Things to Consider

Standard weights are*vitally*important to safe flight.

Also, according toTitle 14 of the Code of Federal Regulations, you must familiarize yourself with the aircraft’s gross weight.

There are many things that are significantly affected by the weight of the aircraft, so getting to grips with mass and balance is really key. Here are several areas that are affected by aircraft weight and balance: –

### Structural Limitations

Every airplane will be designed with certain weight limitations in mind. The weight on the gear and the forces generated while maneuvering is based on well-defined tolerances.

Increased weight leads to increased stress on the aircraft. Too much weight will lead to too much stress, which isn’t good!

### Fuel Efficiency and Range

If you’ve readour article on flight forces,you’ll already know that to maintain level flight, lift must overcome weight.

In a nutshell…

More weight means more lift.

Lift creates an interesting byproduct…

*Drag*.

We need to create more thrust using the airplane engine to overcome drag.

More thrust equals more fuel used! So, it is safe to say that a heavier aircraft will be less fuel-efficient and have a shorter range!

### Stall Speed

There comes the point when the wing will stop producing lift and become less efficient.

In aviation, we call this a*stall* (you can read more about it here).

The speed at which the aircraft stalls is influenced by the weight.

In simple terms?

The heavier the airplane, the sooner we reach the stall. So, it is vital to know how much the airplane weighs.

### Handling Characteristics

The airplane is maneuvered around the center of gravity.

This is the pivot point of the aircraft.

Let’s keep it really straightforward…

The further a force is applied from a pivot point, the greater its effect.

The center of gravity is directly affected by where the mass is located on the airplane. By moving and changing the center of gravity, we can ensure that we get optimum handling characteristics.

### Takeoff Distance

As we’ve already stated, the lift must exceed the weight for an airplane to fly. As lift is a function of airspeed, it would be fair to say that we need to fly faster to get airborne when taking off if we have increased weight.

If we have to fly faster, we will need a longer runway.

### Landing Distance

Airplane brakes work by converting kinetic energy (a clever term for the aircraft’s forward speed) into heat energy (through friction).

But get this…

The brakes*do*have a limit as to how much energy they can convert. The more weight, the greater the kinetic energy. Too much weight and the airplane won’t be able to stop in time.

Throw in the need for increased airspeed due to increased weight, and you may find that the required landing distance exceeds the actual landing distance! Time to consider a diversion.

### Maximum Altitude

Heavier airplane rates mean that the airplane’s cruising altitude will be lower. The maximum ceiling of the aircraft decreases with an increase in weight.

### Rate of Climb

The rate of climb is determined by the difference between the lift produced and the weight. With heavier weights, the difference is reduced. This will lead to a reduction in the rate of climb.

In areas with high terrain, you could find that you need to ensure minimum rates of climb, so pay careful attention to the airplane weight.

### Rate of Turn

The radius of turn is a function of the airplane’s speed. Greater weight means higher speed. And, higher speed means an increased turn radius. If you areinstrument flying, the radius of turn can be crucial when flying procedures accurately.

### Airplane Stability

In extreme cases, excessive weight can cause the airplane to behave unpredictably. Most trainingaircraft are inherently stable. However, if the weight isn’t within defined limits, this can quickly change and createdangerous situations.

## Standard Weights in Aviation – Why Do We Use Them?

It might be a little obvious, but*all*things on board an aircraft, whether big or small, add up. While some things may only weigh fractions of a pound, they can contribute significantly to the airplane weight when summed together.

Imagine adding*all*the things on board an aircraft every time you fly?

It would get a little tedious, right?

To make life simpler,aviation regulatory bodiesallow pilots to use standard weights. Most standard weights in aviation use well-defined averages. Here’s a quick list of a few defined standard weightsaccording to the FAA: –

- Pilots
- Crew
- Passengers (males, females, and children)
- Baggage
- Hand Luggage
- Sports equipment
- Animals

But (and it’s a big but)…

If you*do*know the*actual*weights of things on board, it is mandated that you must use them.

## Aircraft Standard Weights – Commonly Used Terms

Aircraft standard weights can be a little daunting, and you’ll encounter many technical-sounding terms during youraviation studies.

Here at Pilot Institute, we like to make things simple.

Here’s a quick list of common terms you’ll encounter when discussing standard weights and mass and balance in private aviation…

### Center of Gravity

The point on the aircraft through which all weight acts. You can consider this the ‘pivot’ around which the airplane maneuvers.

### The date

An arbitrary ‘line’ is used as a point of reference for weight and balance measurements. When looking at anairplane load sheet,constant reference will be made to the ‘datum’. This is normally defined by the airplane operator, and you’ll typically be able to find out where the datum is in the airplane flight manual (AFM).

### Delta

You’ll often seea small triangular symbolon load sheets and aircraft trim tables. This symbol is called ‘delta’. It is normally used to denote a changeable value or variable.

### Dry Operating Weight (DOW)

As the name suggests, the aircraft’s dry operating weight is the total weight, including all operational equipment, but no liquids. It includes your weight (as the pilot). However, it doesn’t include: –

- Fuel
- Oil

And, yes, the DOW*does*include you as the pilot. However, it does not include the passengers.

### Index

Ever tried to divide, add, or subtract large numbers?

It gets tricky.

1 million divided by 500,000, while simple, takes a little thought. How about 10 divided by 5?

Much easier, right? Same answer, easier math.

Like the above, airplane manufacturers will often specify an ‘index’.

Simply put, this is a large constant divisor (normally in multiples of 100 or 1000’s) used when calculating aircraft weight and balance to make math easy.

### Max Landing Weight (MLW)

This is the structural limit of the airplane on landing. It includes*everything*that will be on board the aircraft.

### Maximum Takeoff Weight (MTOW)

This is the maximum permissible weight of the airplane on takeoff. Be advised that this can change.

Wait, what? How?

While generally, it is a structural limit, it may also be changed depending on runway length, minimum climb gradients, and the useful load you carry onboard.

This is really one to watch.

You will often find that you have to take less fuel with a full load of passengers and bags, or vice versa.

### Maximum Zero Fuel Weight (MZFW)

This is the structural limit of the aircraft, including everything*except*the fuel.

### Mean Aerodynamic Chord

This term uses a straight line drawn through the wing to express the center of gravity. It is given as a percentage, with the wing’s leading edge being 0% and the trailing edge being 100%. You can readmore about chord lines here.

### Moment Arm

A moment arm is a fancy aviation term to describe a pivot and lever. The pivot is normally the center of gravity. The lever is a force that an aerodynamic surface (usually the tailplane) applies. It works according toArchimedes’ law.

The further the force from the pivot, the greater its effect.

All the different moments are added or subtracted from each other and balanced on the aircraft to give a total moment.

### Standard Weights

Standard weights are used to make life simple when calculating aircraft mass. They are normally applied to items such as fuel, oil, other fluids, occupants, and bags.

### Specific Gravity

Specific gravity is the correction factor applied to a given volume of liquid on board the aircraft. It is normally a decimal number used to determine how much the fuel or oil weighs.

### Useful Load

Useful load is added to the aircraft’s dry operating weight to give the takeoff weight. It includes: –

- Pilots
- Passengers
- Baggage
- Fuel
- Oil
- Cargo

Want an easy way to remember what’s included. If it’s burned, paid for, or paid to be on the aircraft, it normally counts as a useful load.

## How are Weight and Balance Calculated Using Standard Weights?

Now that you are familiar with some terms let’s take a quick look at how weight and balance are calculated onboard private airplanes.

It’s all to do with moments.

In short, we need to know two things when it comes to airplane weight: –

- How much various items weigh
- Where the items are located

We can work out their effect on the aircraft if we know these things.

To see what we mean, look at the simplified table below…

Item | Weight (lbs) | Arm Length (in inches) | Moment Arm |

Aircraft DOW | 1700 | 35 | 59,500 |

Fuel (30 gallons) | 180 | 4 | 720 (1400) |

Oil (1 gallon) | 7.5 | 36 | 270 |

2 x bags (30lbs each) | 60 | -5 | -300 |

TOTALS | 1947 | 60,190 |

Here’s how it works.

You’ll normally see tables detailing the weight of any additional equipment (including fuel, oil, passengers, and bags).

You’ll also be given the area where it sits on the aircraft relative to the aircraft datum. Just like on a see-saw, adding different items in different places will change how balanced the airplane is.

By moving either the distance from the datum or the weight (or both), we can ensure the airplane is correctly in trim and balanced. The box on the lower right side of the table giving a*total*moment arm is important.

Airplane manufacturers will dictate a range of allowable values that we must stay within for the aircraft to be balanced.

Let’s say that the range was from 60,000 to 60,870.

If we loaded 350 lbs ofEXHAUST(assuming standard weights around 58.2 gallons), how close would that put us to the limit?

If you’ve inserted it into the above table, you’ll notice that it gets pretty close! So, we know that if nothing else changed, that’s the max fuel we could take.

Oh, and one more thing…

Notice the minus sign?

The standard convention is that any number with a (-) is*ahead*of the datum. Any positive number is behind the datum, toward the airplane’s tail.

By summing these arms, we can determine whether the airplane is balanced within allowable limits.

## Where Can I Learn More About Aircraft Weight and Balance?

Weight and balance is a pretty big subject, and a lot of thought goes into calculating the aircraft’s weight long before you get into the cockpit.

Manufacturers weigh the airplane using several calibrated scales and some pretty complex math to arrive at the common values you’ll see in the AFM.

The Federal Aviation Administration has an excellent guide on aircraft mass and balance that is well worth reading.

## Final Thoughts

Standard weights are used for commonly carried items onboard aircraft, making the calculation of mass and balance much simpler. Volumes of fuel and oil vary in mass depending on temperature and type, so it pays to know a few of the standard conversion factors. Aircraft weight is significant in how an airplane performs. If you want to learn more about airplane mass and balance,why not check out our flight courses, where it is covered as part of our syllabus.

## FAQs

### What is the FAA standard weight? ›

The new FAA standards will increase an average adult passenger and carry-on bag weight to **190 pounds in the summer and 195 pounds in the winter**. Up 12% from 170 pounds and 175 pounds, respectively. This includes an extra ten pounds for winter and five pounds for summer.

**What two FAA documents contain information for weight and balance check for aircraft? ›**

**FAA-H-8083-1A, Aircraft Weight and Balance Handbook**, has been prepared in recognition of the importance of weight and balance technology in conducting safe and efficient flight.

**What is the standard weight of Avgas Jet A and water for weight and balance purposes? ›**

Type | Pounds Per USG (32°F) | Pounds Per USG (59°F) |
---|---|---|

AVGAS | 6.14 | 6.01 |

JET A | 6.75 | 6.68 |

JET A1 | 6.75 | 6.68 |

Water | 8.35 | 8.33 |

**What are the weight requirements for plane? ›**

Most airlines will allow you to check one bag and have one carry-on bag. There is normally a maximum weight limit of **50 pounds per checked bag** as well as a size restriction. The most common maximum size bag allowed is 62 linear (total) inches. A common size bag for checking through is: 27" x 21" x 14".

**What is the weight limit for FAA Part 23? ›**

(a) Certification in the normal category applies to airplanes with a passenger-seating configuration of 19 or less and a maximum certificated takeoff weight of **19,000 pounds or less**.

**What are three items included in the weight and balance report for every aircraft? ›**

The weight and balance system commonly employed among aircraft consists of three equally important elements: **the weighing of the aircraft, the maintaining of the weight and balance records, and the proper loading of the aircraft**.

**What are the 4 required documents to be on board the aircraft? ›**

We'll start on familiar ground, with the mnemonic AROW. The letters stand for the documents that must be carried aboard an airplane. They are an **airworthiness certificate, registration certificate, operating limitations, and weight and balance information**.

**Are you required to do a weight and balance for every flight? ›**

**The regulations do not explicitly require you to calculate your weight and balance before every flight, however it is implied**. The regulations stipulate that you calculate your takeoff and landing distances and operate the airplane according to the AFM.

**What is the formula for aircraft weight? ›**

**W = SUM(i=1 to i=n)** [wi]

This equation says that the weight of the airplane is equal to the sum of the weight of “n” discrete parts.

**How much does a pound of 100LL weigh? ›**

At standard temperature and pressure (STP), which is 15°C (59°F) and 1 atmosphere of pressure, 100LL avgas weighs approximately **6.02 pounds per gallon** (0.72 kg/L).

### What is the weight checking formula? ›

The formula is **BMI = kg/m ^{2}** where kg is a person's weight in kilograms and m

^{2}is their height in metres squared. A BMI of 25.0 or more is overweight, while the healthy range is 18.5 to 24.9. BMI applies to most adults 18-65 years.

**How much does 1 gallon of avgas weigh? ›**

All grades of avgas that meet CAN 2–3, 25-M82 have a density of **6.01 pounds** per US gallon (720 g/L) at 15 °C (59 °F). (6 lb/U.S. gal is commonly used in America for weight and balance computation.)

**Is weight and balance required for Part 91? ›**

While there are no specified requirements for the Pilot in Command (PIC) operating under 14 CFR Part 91 to conduct weight and balance calculations prior to each flight, 14 CFR 91.9 requires the PIC to comply with the operating limits prescribed by the manufacturer.

**What is the maximum ramp weight? ›**

The maximum ramp weight (MRW) (also known as the maximum taxi weight (MTW)) is the maximum weight authorised for manoeuvring (taxiing or towing) an aircraft on the ground as limited by aircraft strength and airworthiness requirements.

**What is the FAA drone weight? ›**

All drones must be registered, except those that weigh **0.55 pounds or less (less than 250 grams)** and are flown exclusively under the Exception for Recreational Flyers. Drones registered under part 107 may be flown for recreational purposes as well as under part 107.

**What is the average pilot weight? ›**

While the maximum and minimum weight mentioned the table is **46 kgs to 82 kgs**. And when it comes to the age range, the age has some ranges starting from 15 years and ending at 48 years. But the required age for a pilot is 15-24 years staring from NDA to CDS, NCC entry and AFCAT entry.

**What is the standard carry-on weight limit? ›**

Carry-on bags must weigh **less than 35 pounds** and must not exceed 10 inches deep, 16 inches wide and 24 inches high. Bags must fit in the overhead bins. Checked bags must be no longer than 62 linear inches (length + width + depth) and must weigh under 40 pounds.

**What is FAA heavy classification? ›**

A heavy airplane, as classified by the FAA, is **any airplane with a maximum takeoff weight of 300,000 pounds or more**. If an airplane has a maximum takeoff weight of 300,000 pounds or more, it's classified as a heavy airplane.