Rule 17.3 1-G turn/transition

[drewshotsfan]

Hi Guys

Just checking if this rule is correct?

Currently worded as 1.5 times the drag (rounded up) of an a/c's 2G turn/transition drag. This means that a 1G turn causes MORE drag than a 2G turn!

Should it not be less drag for less G? Should the calculation be the 2G drag DIVIDED by 1.5, instead of multiplied by 1.5

In the example given the calculation for 2x 1G turns is:
1.5x2=3
2x3=6 drag for 2 1G turns

Should the calculation for 2x 1G turns actually be this:
2 divided by 1.5 = 1.33
1.33 x 2 = 2.66 rounded up to 3

So therefore 2 1G turns would incur a total of 3 drag (which is less than 2 2G turns at 4 drag) instead of 6 drag (which is more than 2 2G turns, which is my point really..........surely the drag should be less for a 1G turn)

The problem comes with executing only 1 turn at 1G, because you end up with 1.33 drag, which if rounded up is the same cost as a 2G turn? Can we have 0.5 drag amounts? So a 1G turn would cost 1.5 drag versus a 2G turn costing 2 drag

All of theses are based on the SE5A in the 0 - 2.95 altitude band, as per the example

Just a thought?

Cheers

Drew

[admin]

Hi Drew,

Ready for a short lesson in aerodynamics? Apologies if I cover stuff you already know. Drag on the aircraft is from two sources, parasitic and induced. Parasitic drag or form drag is created when the aircraft moves through the air. This drag increases with the square of velocity, basically the faster you go more parasitic drag is created.

Induced drag is the drag created when lift is produced. This form of drag will decrease with speed. As you can see on the attached table there is a speed where the drag on the aircraft is a minimum. Since the numbers on the data card are rounded to a whole number you can't see this very clearly.

   
When the aircraft is banked, the lift vector, see Figure 16.7 in the rules ;-) is at an angle to the horizon, the vertical component does all the work keeping the aircraft altitude constant. The horizontal component causes the aircraft to change heading. The problem is the vertical component must equal the weight of the aircraft or it will lose altitude. The angle of attack is increased to provide more lift which increases the induced drag component. A large number is now larger and the facing drag is greater when the speed is low. At high speed, the form drag is large and the induced drag is low and the drag from facing (the horizontal component) is less. The result is facing drag is higher at low speeds

The airframe drag is for an aircraft in level flight, lift = weight. Change the angle of attack and the total drag will also change. If you plotted the airframe drag value vs. speed you will see the same graph as the attachment.

I tried to avoid fractions in the thrust and drag, they are present with Climb Drag and Dive Thrust. The fractions could be carried but I thought it would be easier on the player to round up.

Does this answer your question? If not please let me know

Cheers,

Steve