- THRUST makes the plane go forward and allows the plane to climb using LIFT
- DRAG slows it down
- WEIGHT brings it back down to earth
- air molecules will rush over the wing at a a faster speed,
- and subsequently the wing will be able to generate more width.
- As the plane flies higher the air molecules will be less dense - slowing down the lifting effects.
- As the airspeed increases the wing will be subject to more drag
- Parasitic Drag, and
- Induced Drag
- Cl = Coefficient of Lift (a constant, non-dimensional term - used primarily to compare
different wings with one another)

*S*= Surface Area of the Wing

*V*= Velocity

*p*= Air Density

Drag =

- Cd = Coefficient of Drag (a constant, non-dimensional term - as above - a function of
*alpha*(*Angle of Attack*))

*p*= Air Density

*V*= Velocity

*S*= Surface Area of the Wing

- Airfoil Shape as described by the relationship between
*Cl*and*Cd*(Coefficient of Lift and Coefficient of Drag) - Alpha or
*Angle of Attack* - As Alpha is increased so does the
*Cl*and*Cd*but at different rates! - When the ratio of
*Cl*and*Cd*is greatest*L/Dmax*is achieved (*L/Dmax*does not provide the greatest lift, but the**greatest lift for the the least drag**) - Maximum endurance
- Maximum Climb Angle
- Maximum Power-Off glide range
- Stalls, or
- Breaks (structurally)
- Instanatneous G is a function of
*Cl*, whilst - Sustained G is a function of
*Cd*__and__*Cl* - The plane decelerates, or
- G is reduced to the point where engine thrust can cancel out the drag created by this lower G setting
- Reduces the amount of
*Drag*at a given*AOA* - Limits the amount of
*Lift*that*Thrust*is capable of generating from the wing - Creates a lot of
*Lift* - May create more
*Drag*than Engine*Thrust*can overcome

**CHAPTER 1Beginners Guide to Aerodynamics**

I am currently having diagrams and graphs drawn up for inclusion on this page to help ease the learning curve and facilitate understanding of these sometimes highly complex issues!!

**Real Basics...!**

There are 4 forces which act on an aeroplane: LIFT, DRAG, THRUST and WEIGHT.

If THRUST is equal to DRAG the plane will maintain a constant speed, if the wings generate
enough LIFT to equal the WEIGHT the plane will maintain a constant altitude

__However, increase THRUST with the above model in mind and the following will happen:__

__At this point in time another 2 effects will come into operation:__

**Drag, the two main types...**

There are 2 main types of Drag worth knowing about, these are:

Prasitic Drag is a force most of us have experienced when we've stuck our hand out of
the window of a moving car! Asides from the fact that it's a dangerous thing to do, it is
a good way to examine the drag imposed on a 25 ton fighter. What is obvious is that as
speed increases so does *Parasitic Drag*, BUT it does not do so proportionally -
double the speed and you will effectively QUADRUPLE *Parasitic Drag*! **Aeroplanes
with swept wings experience a reduction in Parasitic Drag**.

As the

**Math Anyone...!?**

The formula for lift and drag show how these factors come into effect:

Lift =

L = Cl ½p V^{2}* S

D = Cd ½p V^{2}***** S

T__hese are some of the simpler equations available to to allow Lift and Drag
relationships to be explored. There are however 2 other factors which effect Lift and
Drag:__

Alpha is defined as the angle at which the Wing cuts local wind coming across it

With this all in mind it can therefore be seen that ** Cl and Cd alone can
be used to compare different wings** for the simple reason that

Having said that it should be remembered that

**Yeah, Yeah...but what does all this mean to me: a humble PC
Pilot...?!!**

L/Dmax has three important implications on your plane and the way you fly it:

Bear these three factors in mind when evaluating the 'Realism' of a flight sim and whilst evaluating your aircrafts performance - But to gain a deeper understanding of how your flight sim should handle read on...

**Right, back to technicalities...**

*Maximum 'G'* is the number of times the pull of Gravity a wing can take before it
either:

Often referred to as* Instantaneous G* it is often achieveable only momentarally,
as airspeed and thus lift will decay rapidly during high G manouvers (Some aircraft are
exempt from this rule, for example the latest block F-16, which can maintain a force of 9G
and acclerate whilst doing so)

G creates more drag and it should be remebered that:

Ok, so lets try and simplify things - if there isn't enough thrust to overcome drag at *Maximum
G* then one of 2 things will happen:

If the latter occurs, we call this point *Sustained G. *Whilst *Instantaneous G*
is usefull in a situation where you need to pull the nose of the plane up for a quick snap
shot, or to break hard in order to shake a bandit off your tail, *Sustained G* is
more Advantageous Tactically: **the ability to sustain a given G is a measure by which
one fighter will be able to continuously outurn another fighter**

**Right, lets start looking at the real application of all
this...! **

** W/S or Wing Loading** (

Therefore: If you have two fighters both weighing the same generating the same thrust, with the same aerofoil -

Again, comparing 2 aircraft in terms of their

**Other Parameters...**

*Specific Excess Power* or *Ps* is a measure of the difference between
an aeroplanes *Drag* and its *Thrust*

Wings generate *Lift*, but they also create *Drag* as we already know:

__A small wing does the following:__

A large wing does the following:

Regardless of wing size, when *Thrust* exceeds the amount of *Drag*
generated, the aeroplane can climb or increase speed or do both and it is this excess wich
is labelled *Ps*.

*(Ps *is measured in Feet per Second)

Ps Formula =

*Ps = Thrust minus Drag x Velocity, divided by Weight*

Tactically speaking, **an aeroplane with a high Ps should be able to out
accelerate, out climb and outurn an opponent with a lower Ps**