It is true, all model aircraft need to be kept as light as possible for optimal performance. The weight of RC planes is different based on the model and kit so it is hard to say exactly how much an RC plane weighs without looking at a specific model.
In general most RC planes will weigh between 2.5 and 3.5 pounds but there are many smaller and larger RC planes that will weigh less or more than that.
If you are looking at a particular model of RC plane you can normally find the exact weight by contacting the manufacturer or looking at the spec information.
For example, the Koala RC plane’s weight is 2.87 pounds. That number includes the fuselage, wheels, nose gear, 3 servos, engine, and fuel tank (empty), but once you add in the weight of the fuel it will certainly go up.
Wings with aileron servo and covers weigh 250g and fuel weight was 120g. After finishing the full set up estimated weight is 4lbs total.
This is a training RC plane so weights can obviously be different based on kits, engine, and fuel.
Are batteries the main source of weight in RC planes?
In an RC plane, batteries are often the main source of weight along with them being the main source of power as well. Different models have different types of batteries but most RC planes at minimum use a 2200mAh battery for a minimum flying time around 6-7 minutes.
What should we do? Should we use a minimum power battery to reduce weight? A 2200mAh LiPO battery weight is around 6-10ozs and it gives a flying time that is honestly quite low as A 10 minute flying time is standard.
In most cases it is better to upgrade the battery to get a longer flight time than it is to have the lighter at battery possible while having a minimal flight time.
A 6S 5000mAh LiPo battery weighs almost two pounds while two 6S 3300mAh packs weigh 2lbs 5ozs.
If you can avoid using multiple batteries then you can reduce the weight of your place while also getting the longest flying time possible.
Another thing is if we use an 8s 5000mAh battery the 8S pack contains 33% more energy than the 6S pack.
So using a battery pack like that you can get some extra flying time. You will have to balance the weight of the batteries vs.the flight time as once you reach a certain point larger and heavier batteries will actually reduce the flight time rather than increase it so it really is a balancing act. .
How does weight affect the flight?
There are four different forces of flight those are:
Thrust: Thrust is created by the engine and moves the RC plane forward. The engines push air back with the same force that the air moves the plane forward so the stronger the thrust the faster the plane will go.
Drag: Drag is an opposite of thrust. Imagine you stick your hand out of your moving vehicle and “fly” your hand. The force that pushes your hand back is called drag. As your hand pushes on the wind, the wind also pushes against your hand.
Lift: Lift is crucial because until the lift equals weight the RC plane won’t be able to fly. When an RC plane or RC vehicle sits on the ground it doesn’t have any lift but only weight. When the plane starts to go down the runway the lift also increases. When the lift equals weight the plane can take off.
Weight: Weight and lift are the same when a plane flies level at a constant velocity because excess weight requires more lift and therefore more thrust. Heavy planes are more difficult to get off the ground as compared to lighter planes since planes with less weight require less thrust. That’s why RC planes are typically designed to be as light as possible.
I am mentioning the factors because I already told you that if you have maximum battery power then you can have maximum flying time. That is true but there is a problem.
The RC plane’s engines have a power limit. These engines can’t generate more than that limit and as mentioned above as the weight increases then you will also need more lift and thrust to be generated by the engines.
Suppose your RC plane’s weight is 2.5lbs including the battery. If the battery is approximately 2200mAh that means it will weigh 6-10ozs. In that case, you can fly a maximum of 7-10 minutes.
If you want to increase your flying time then you might use a 6s 5000mAh battery that weighs 1.5lbs or more. That means now your plane weight is approximately four pounds
Now your RC plane’s engines need to generate almost 2 times more power and that isn’t even possible for most RC planes. So before making any update or adding extra weight via batteries make sure your engine capability can handle the weight.
Balancing Your RC plane’s weight
Balancing weight is very important as suppose your RC plane’s tail becomes heavy then what will happen? In a tail-heavy plane, as it looses lift and approaches stall speed, the tail will drop.
This is the worst possible thing that could happen!
You’ll lose airspeed and it will rapidly move into a full stall and dive likely resulting in a crash.
So balancing the weight of your RC plane is obviously very important. Before balancing the airplane you should consider a few things.
- If you are using an RC plane that is powered by a nitro engine then always make sure the fuel tank is empty when balancing the airplane.
- Mark the wing at the location indicated in the manual. With the airplane facing towards you, place an index finger on each wing exactly where you made the marks.
- Raise the RC plane. When your plane is perfectly balanced it will still be level on your fingertips with the nose just slightly downward.
Every RC plane manual will tell you exactly where the center of gravity for the airplane should be.
Balance without adding weight
Many times RC planes can be balanced without adding weight. This is made possible by moving the battery pack. If your RC plane’s nose is heavy then the nose will fall or if your tail is heavy then the nose will rise.
If the nose becomes heavy then see if you have any space to move the battery pack towards the rear of the RC plane. If the tail becomes heavy then move the battery pack forward.
This is a trial and error type setup so you have to check the balance each time you move the battery pack. When your RC plane is finally balanced with the nose slightly down be sure your battery pack is secure.
Balance by adding weight
Depending on the weight of the engine or motor it may be necessary to add weight to balance the plane properly. Any weight added needs to be as far away from the center of gravity as possible to minimize the amount of weight needed.
If your RC plane is nose-heavy then add weight as close as to the end of the fuselage as possible or if your RC plane is tail heavy then add some weight on the firewall.
What to Use for Weight?
Anything can be used for a weight that would not harm the body of your plane. You can use nuts, bolts, fishing weights, or anything that can be fastened securely to the airplane. You can also buy some weight that is specifically designed for balancing RC planes.
You can find the weights that are specifically designed for RC planes by clicking here.
Some people even just use pieces of tape as with most smaller RC planes the amount of weight needed to balance them is often quite small.
Does weight affect an RC plane’s battery life? Yes, as much as you increase your plane weight your plane engine needs to generate more power for lift and thrust. Engines get power from the battery and if the weight increases dramatically the engine will drain the battery much more quickly.
Extra weight can even damage the engines if they are not designed to handle that much weight By adding extra weight to an RC plane the battery life will inevitably be shorter.
The weight of an RC plane can vary by a considerable amount depending on the make and model as well as the type and size of the battery pack. In most cases RC planes will only weigh between 2.5 and 3.5 pounds but there are certainly larger RC planes that can weigh a lot more.
Since planes can fly no matter how much they weigh the only size restriction is that the larger the plane is the more battery power or fuel it will consume making it more expensive to operate.
If you want to know exactly how much an RC plane weighs you can often find that out by contacting the manufacturer or if you have already purchase the plane you can easily use a kitchen scale to get its exact weight.