Box visualisation
 

Gentlemen, I'm having one of our chaps plugin the dimensions of a typical F3A box into a 3D visualisation program. Thought it would be good to see the real the optical distortion of shapes as we change baseline height, box distance etc.

I just need some professional input seeing my Pattern experience is at best classed as pre-amateur.
From the screen shot you can see that a box that is Ca165m out will give you a horizontal width of Ca 550m.
Now the geometry will dictate the hight. See very basic drawings.
Of course, the lower the height the longer distance we have to execute the manoeuvres.
I understand some manoeuvres will demand extra hight, this is just a generalisation.

Questions: What top of box height is most people using? When you're pulling a vertical 8 is that x2 the hight of the turnaround radius? What point alone the horizontal path would we be pulling to 45deg for the turnaround? At which hight are most of you flying the baseline?
You get the idea:
Look forward to you feedback.

This is a cool topic... in my opinion I use mostly option 2. And I say Mostly, because on the width point of view of the box, for example, consider in P 15 the central stall turn with 1 1/4 roll up and 3/4 roll down. It would be geometrically impossible to make the following half reverse cuban eight using option 1 as the radius of exit of the stall turn would leave you already too late to start the reverse cuban eight.

Now going through P 15 anf F 15 over your drawings, and keeping the analysis width-based makes me think that if i have been subconciously flying option 2, then my central cuban eight with 2 / 4 pt roll and oppositye 1/2 rolls after the knife edge humpty is ending up very big. There is room to make it smaller. It seems to me like its a smaller maneouver that what i am making.

Now talking about height of the box, another point is, that if for example in option 2 we have a top line of 110 m, it would be impossible to make what we call the "astronaut maneouvers". the 4 pt figure 9 in P 15, or the 4 pt figure nine with integrated roll on top 180° on F 15.

I would encourage you to extend your interesting work on seeing how would it look in this same scheme for exaple the figure 9s in P 15 and F 15, the Vertical 8 on F 15, the vertical hourglass on P 15, and even the last two maneouvers of F 15: the humpty bump with oposite 1/2 rolls and full roll down, and the stall turn with 6 / 8 pt roll un the way up and 1 3/4 snap on the way down, which are in my case, very tall maneuvers.

Anybody has their 2 ct to share?

Mvelez, I thought it would be rather neat... least thats two of us;-)

Having spent all my life producing artwork for the commercial industry i can tell you, what we perceive as straight, round, vertical etc... isn't! Symmetrical shapes have a distinct distortion when viewed at distance and from various angles. A simple, geometrically perfect square loop performed directly in front of you won't appear actually square, exactly the same thing with a simple 360deg loop. Place them at the end of the box and the effect/distortion is even more pronounced. One doesn't even need to perform a manoeuvre... as simple straight pass from one side of the box to the other will have a distinct climb as it comes to centre and the complete opposite as it progresses to the other end. Even more so if performed along the top of the box. I thought it would be neat to see exactly what happens.

What I need to start is a general base line height or simple just an angle, same applies for the top, but that isn't so important as it's very obvious that the top line, or indeed the radii being flown can't actually "be" fixed in reality. There must be a considerable amount of "pilot license" in operation and, as the judges can't genuinely compare (or accurately remember!) a manoeuvre flown at one side, with one flown in the centre... I guess that "License" will be used to the max. Albeit subconsciously.

One thing I noticed when doing sketches was that if you place a vertical at 45deg past centre, you will see 45 deg of the aircraft. At 60deg you will see 60deg of the aircraft. And that is regardless of height or distance, it's the same. If one orientates themselves with how there aircraft looks when viewed at 60deg and marks the wing accordingly... well it wouldn't be a hindrance. Rocket science its not... but very neat when you see it. The 45 deg lines also reveal some genuinely interesting (and understandable once you've been introduced the perspective) phenomena.

What I plan to do is plot in some basic shapes in 2D and then project them in 3D to see the actual shape/perspective distortion. And then, Plot in geometric perfect shapes in 3D and the project that in 2D to see the actual shape/stick inputs you'd have to used to achieve it.

There must be a pile of telemetry out there, if a few of you guys can throw out some basic (or a good guess) numbers, I can plot them in after Easter.

Great stuff. I have found that with the tendency to do larger maneuvers we do them a lot higher and it is a lot more difficult to determine what is level and what looks like level, etc. I can get you some GPS altitude data but I don't know how good it is. It is also difficult to find a place inside the plane to measure static pressure. From experience, I'm guessing we hit 800 feet at times.

Can't wait to see your drawings.

Jim O

Remember, the 60 degree rule applies for the TOP of the box too, so that's 286m at Ca 165m out. 938ft.

Peter+

Excellent Peter, so now we have an absolute top.
Anyone have a baseline...20-deg or about 90m?
Telemetry/rough numbers anyone?

I would assume you are aware that all of the maneuvers do not have to have the same radii. So the height of a half reverse Cuban 8 on the end of the box will probably be lower than an avalanche in the center and certainly lower than the hour glass in the center.

I looked at some telemetry data and the GPS altitude is not believable. I would guess the baseline will be at 40 to 60 meters.

Jim O