Как влияет ЦТ вашего ВС на летные характеристики ?
Когда вы загрузите ваш самолет пассажирами, сумками и топливом, вы должны убедиться, что центре тяжести (ЦТ) в пределах. И вы, наверное, знаете, что, когда вы перемещаете ЦТ вперед или назад, это влияет на производительность вашего самолета. Но как это сделать? Давайте взглянем.
Если вам нужно больше подъемной силы, вы создаете большее индуктивное сопротивление, и ваша производительность падает. Но почему скороподъемность и расположение ЦТ связаны?
Закон балансировки самолета
Your lift acts upward from your wing, at a point called the center of lift. And the center of lift, as long as you are within the aircraft's CG limits, is always aft of your CG.
If you look at the diagram below, you can clearly see that if you didn't have a tail creating its own force, your airplane would nose straight down because of the rotation force called torque.
Your elevator (or stabilator) balances out the torque by creating another downward force, called tail-down force, by generating torque in the opposite direction.
How Torque Comes Into PlayThe torque calculation is pretty simple: Force X Distance = Torque. So if you have a large amount of force at a small distance, it can be balanced out by a small amount of force at a large distance. You can see it in the diagram below.
So Lift And Weight Don't Equal Each Other?One of the first things you learn as a pilot is that in level, unaccelerated flight, lift and weight equal each other. But that's not exactly the case.
When you look at the diagram below, what you really see is that weight and tail down force both need to be balanced out by lift. Essentially, lift needs to equal weight and tail down force.
How Does Drag Factor In?When you create more lift, you create more induced drag as well. So as you can see, when your CG is forward, you need more tail down force, and more lift. You generate that extra lift by increasing your angle of attack, which in turn increases induced drag.
And as always, when you have more drag, you decrease performance.
How Much Difference Does It Really Make?Before you go throwing everything possible into the baggage compartment, consider this: while having an aft CG definitely improves performance, in most light aircraft, the difference in will be a few extra knots of airspeed, and a little better climb rate.
So if you're taking a long cross country, an aft CG might help you get to your destination a few minutes early, but in most cases, it won't make a huge time difference.
http://www.boldmethod.com/learn-to-fly/performance/how-does-cg-affect-aircraft-performance/
