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There was a question yesterday about landing in a wingsuit; the main issue is, of course, the high speed, both vertically and horizontally. One way to reduce speed is flaring; another would be to gain height, which apparently is possible: One of the answers there links a video of a wingsuit pilot ascending from a lake bed to the height of the crown of a dam. However, the climb is modest and the pilot actually accelerates beforehand to fly that maneuver, so that the resulting speed after the climb is probably not lower than usual. In order to shed more speed, the climbing angle would have to be steeper. One extreme case of such a landing is "trampwalling" (see e.g. here): A trampoline jumper is able to land safely on a hard surface at the crest of a parabola where their speed is near zero.

My question is in the title: What is the maximum climbing angle that can be achieved with a (potentially modified) wingsuit? If it is steep enough, a lot of kinetic energy could be shed by climbing, and the landing would be much less dangerous, provided the terrain permits. I have created a little sketch of the idea:

Terrain and trajectory of a landing while climbing

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    $\begingroup$ You can achieve any angle: it is just "turning up". You lose lift, but with enough speed it is not a problem (for short of time). Like acrobatic aircraft. "Turning" is not a problem. Keeping speed (and so control) and lift is a different question $\endgroup$ Oct 19, 2023 at 11:04
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    $\begingroup$ This landing would be more dangerous than a flare over a long, flat surface. The slightest misjudgment of the flare could be catastrophic. Flare too late or too little and you slam into the wall at speed, too soon or too much and you stall and slam onto the ground. I appreciate that it's not the core of your question, but if you are thinking about this as a viable way of a wingsuit to land it isn't. $\endgroup$
    – GdD
    Oct 19, 2023 at 11:38
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    $\begingroup$ @GdD Yes, I understand that as with all other flying, not much untoward can happen before you get close to the ground, which is why that's typically avoided except when we have to, for landing, and we want to do that as safely as possible. That said, any landing in a wingsuit seems batshit crazy, so the difference seems gradual ;-). I assume one could keep enough distance for necessary corrections from the ascending ground (which implies terrain that rises slower than one's own proven ascent capability) until it's actual landing time. $\endgroup$ Oct 19, 2023 at 15:51
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    $\begingroup$ I don't understand this question. A wingsuit is just a flying device, like any other. With enough speed and enough lifting surfaces it can do a loop. @Peter-ReinstateMonica, with this in mind could you make clearer the limitations we must impose? Otherwise I feel the answer is "Vote to close". $\endgroup$ Oct 19, 2023 at 16:06
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    $\begingroup$ I think this is a valid question. With enough speed anything can do a loop but it is not trivially the case that a wing suit can pick enough speed at terminal velocity to complete such a maneuver. $\endgroup$
    – Sanchises
    Oct 19, 2023 at 17:25

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Wrong: A climb of 64 degrees was momentarily reached by Luke Rogers on Sept. 9, 2018 near Brisbane, Australia. This was 65 seconds into his flight track, where the climb rate was 153 km/h and the ground speed was 74 km/h. The flight track shows that this climb was preceded by an even steeper dive.


Correction:

In many other flight tracks on that website, the second plot's vertical speed is almost always positive. But common sense, corroborated by the third plot's "Height", says that the wingsuit is usually falling, not rising. So "vertical speed" is inverted, a surprise for other kinds of aviators.

The steepest climb in this track, then, is where the second plot's red line is well below zero, and the green line is also low.
At 26 seconds, vertical speed is -91 km/h, and ground speed is 129 km/h. 35 degrees.
(At 56 seconds, -66 and 107, so 32 degrees.)

This flight was intended to maximize the total height of a climb, so for efficiency it probably didn't also maximize climb angle. Other flight tracks on that website may have steeper climbs. To find them, one could collect each https://skyderby.io/tracks/99999 (tricky: some numbers are missing), save that .html file, parse spd_chart.series[0] (ground speed) and spd_chart.series[1] (vertical speed), and at each time point calculate the inverse tangent to get the climb angle.

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    $\begingroup$ That's interesting, but I don't understand the reluctance to push the wingsuit to higher angles of attack. If the airspeed were still ~norm<74,153> = 170kph, then there must have been considerable directional control still. $\endgroup$ Oct 19, 2023 at 18:58
  • $\begingroup$ You're right. Deceleration due to gravity at a climb angle of 64 degrees is already 90% that of a purely vertical climb. So going a bit steeper for a few seconds (5 seconds is all it takes to go from 170 km/h to 0) hardly matters. $\endgroup$ Oct 19, 2023 at 19:08
  • $\begingroup$ First time I have seen a flight track, but looking at it: Judging by the red line in the second chart, there seem to be two times the vertical speed dipped into the negative, around T=25 seconds and 55s (even though the pop-up numbers stay positive, probably a defect of the software which cannot cope with this unexpected data); a third time it was almost zero, around 89s. That is corroborated by the blue line in the third chart which has a negative slope during that time. Am I misunderstanding something? (At 65s it's your numbers, but vertical seems positive.) $\endgroup$ Oct 19, 2023 at 21:59
  • $\begingroup$ @Peter-ReinstateMonica, good catch. I've corrected this answer. $\endgroup$ Oct 20, 2023 at 22:28

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