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Graham Dickinson passed away in China on the 25th of January during a wingsuit BASE jump at Tianmen Mountain.

Graham went alone to jump a new exit point on Yuhu Peak, the mountain next to the Heavens Gate. After he failed to check in a search was performed that found his body.

From the location of the body it would appear he tried to fly through the cave.

"i'm not here for a long time, i'm here for a good time"

Not my video, but I enjoyed it. RIP man

https://vimeo.com/201527531

Some further information.

Security cameras confirmed Graham exited from the East skywalk on the 'back side' of the mountain, attempting to fly through the cave in the same direction that Jeb did during the Heavens Gate project.

Is Yahu peak the actual cliff the hole runs trough?
Would that basically be exit and a 180 degree dive turn in and trough the hole?

I found a map and a picture. Can anyone confirm where he exited from? If it's directly over it looks like it would be diving 180 or to the right of the cave then a hard right into it.

The map image shows the glass skywalk on the left, as for the exact exit point we don't know yet.

Graham exited off the "Cliff hanging walkway", making a near 180 degree left turn into the cave. Graham committed to make it through but ran out of altitude on the far side, he did not deploy.

This was the most technical wingsuit exit ever attempted. Low altitude, 180deg turn and long piece of flat terrain to out fly whilst sub terminal.

Just out of curiosity - has that exit been successfully done before? Or, was that the first attempt?

Any idea if he'd calculated a glide/start arc for this kind of exit? Any idea what the numbers were on the flight? No one here will likely argue that graham was going just about as hard as someone can go in the wingsuit base game. I'd never tell someone not to live their dream. Lots of sadness, little shock.

Never jumped before.

We don't know if Graham measured the exit but he normally wasn't a numbers guy.

Would anyone in "the top league " evaluate this exit as "doable" ?

The idea has been talked about and dismissed many times over the years at WWL, it looked so difficult I never measured it.

Chances are I'll be back there later this year and will measure it out of curiosity.

The most technical exit performed to date AFAIK is 180m / 180m, the numbers for the cave look to be more (horizontal) and there is also the turn to account for.

...and the associated accelerated stall that caused him to fall instead of fly through that turn and used up whatever margin there may have been.

Is this a fact or an assumption? maybe he got into his flight but just ran out of altitude...

Both, Mikki.

It is a fact of physics that it takes lift to turn and that unpowered aircraft lose altitude when turned.

It is an assumption that he made his turn soon after launch and probably before full pressurization.

It is a fact that less than fully pressurized wings are less efficient than fully pressurized wings. Therefore, the "accelerated stall" concept applies because a less pressurized wing cannot hold as much weight and still maintain flight in exactly the same way that a rigid wing cannot hold the extra weight of an added G-load and still maintain flight. In one case, lower pressurization increases the effective weight; in the other case, higher G load increases the effective weight. In both cases, the result is the same: the wing quits flying and starts falling, which changes the glide angle and the trajectory.

Beyond that is the fact that whether he technically stalled or not, it takes lift to turn so even if he kept flying the whole time and never fell through any part of his trajectory after initial inflation, the turn did change his glide angle and trajectory.

It is a fact that if you don't allow for this GA/trajectory change, you end up in the dirt if your margins are too close.

I don't remember the exact details of Alexander Polli's last flight, but IIRC he did more or less the same thing aerodynamically: He did a lift-eating maneuver without enough margin.

I have attached a rough diagram of how this looks. This diagram is not to scale and doesn't represent any specific glide angle; it just shows conceptually how turns and/or accelerated stalls affect glide angle and trajectory.

To conclude, I'm not saying he did not get into his flight; I'm assuming that he got into his flight but just ran out of altitude because he didn't properly account for the turn-induced glide angle/trajectory change that ate his margin.

No

Please forgive my ignorance, I am not a wingsuiter, but I have a few questions:

What is the definition of "accelerated stall" for wingsuit aerodynamics?

In your graphs, does the Y axis represent glide angle, or does it represent altitude?

And relatedly then, does the horizontal line represent the ground? Or glide angle of zero?

Thanks!

:(

It's not possible for it to be both. Altitude has units of meters. Glide angle does not have units. But judging by what I see and the "Start" and "Turn" labels, I think the Y axis represents altitude (the horizontal line being the ground, the X axis being the distance traveled, and the slope of the line representing the glide angle).

Good catch. My bad.

Y is indeed altitude, not the glide angle, but Y is also one of the components used to calculate the glide angle (or ratio).

Glide angle is determined by dividing X by Y, as detailed here.

And yes, X = distance and the slope of the line = the glide angle.

Could glide angle, being an angle, be measured as an angle, e.g. 30 degrees from horizontal; or as a vector, e.g. horiz distance:drop 3:1? Both of these would have units.

"Glide angle" as measured relative to the horizon does have units of degrees or radians.

"Glide ratio" is dimensionless (no units), because the horizontal and vertical speed units cancel out:

All correct, I incorrectly referred to glide ratio as the glide angle.

Do the guys who fly wingsuits usually take the altitude lost from a turn into account when they are making overlays of their start arcs? Or is this usually not a big enough issue to consider on most exit points?

Any videos of that successful exit?

https://vimeo.com/137427215

Some diagrams and further description of the jump:

http://www.theglobeandmail.com/...ian/article34415146/

Wow. I'm supposed to hear he was in a Freak2. I would have figured he would at least be in an Aura2/3 if he was attempting an exit that technical. If it's nearly impossible, at least stack the odds in your favor...