Gliding

jedion357's picture
jedion357
April 16, 2011 - 7:09pm
Remaster AD wrote:

Yazirians can glide short distances using the membranies along their sides. A yazirian can glide 1 meter for every meter he is above the ground when he starts. He must start at least 10 meters above the ground. The maximum distance a yazirian can glide depends on the gravity of the planet, as shown below.

Yazirian Gliding Table
 Gravity Max. Glide
 .6G 150m
 .7G 100m
 .8G 50m
 .9G 25m
 1.0G 10m

Yazirians cannot glide on planets with gravities below .6 or above 1.


Question #1: Does the max glide distance make sense? if a yazirian jumped off an 100m building in 1.0G would he only glide 10 meters? Does he suddenly fall to the ground after 10m? I've always interpreted that table as the max glide result is the distance traveled for trading 10m of hieght. (I've argued with a player over this, which was silly since I was the referee and my ruling benefited his character).

Question #2: how far can a yazirian glide in a turn? Or rather, at what speed does a yazirian glide? It doesn't seem right that a yazirian in 1G would only travel 10m while another yaz in .6G would travel 150m in the same time. What I'm getting at is if say gliding speed is 50m per turn then a yazirian in 1G would travel 50m in a straight line while dropping 50m altitude in one turn and a yazirian in .9G will travel 50m horizontally while dropping 20m of altitude in the same turn.

Question #3:Then we have issue of what happens in a steep dive? What if the Yaz opts to drop more distance faster?

Question #4:Then we have what happens if a yaz tries to make an attack while gliding? To glide he must keep his arms and legs out stretched. but to aim a pistol or throw a weapon will cause a loss of glide surface and should result in loss of altitude.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!
Comments:

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thespiritcoyote
May 4, 2011 - 8:16pm
Yeah.... I... umm... what was the question again? Money mouth
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JCab747's picture
JCab747
February 19, 2018 - 10:11am
TerlObar wrote:
Okay, here's an update.  (You're going to get a bit of a physics lessonSmileKiss)

I was able to produce a model that (very nearly) reproduced the flight characteristics of the flying squirrels and sugar gliders using basic physics so I'm fairly confident it is correct or at least close enough.

The main parameters that affect the gliding are:
g - gravitational accelration (I used 1g=10 m/s^2)
m - mass of the glider (AD states that this is 50kg on average for a male Yazirian)
p - atmospheric density (I used 1.2 kg/m^3, a typical value for earth).  This should probably decrease with decreasing gravity but I ignored that for now (reducing it makes the Yaz fall faster)
A - The wing area.  If you look at the picture in the AD rules for a Yaziran make measurements off that, you get at best a 2 square meter total body area.  I decided to go with 3 square meters and assume that they billow out just a bit more than depicted.
CD - The drag coefficient.  This is a measure of how unaerodynamic the body is.  For the flying squirrels this was between 0.98 and 1.07 so I just took a value of 1 for the Yazirians seeing as they are basically the same body shape.
CL - The lift coefficent - This is how much lift is produced by the wing structures.  The flying squirrels had values between 1.48 and 2.12.  Since the Yazirians have gaps between their bodys and the wings (which the squirrels don't), I strongly suspect that in truth they wouldn't be as effiecent but I was generous and used a value of 2.1

The problem the Yazirians have is that they are too massive.  The mass to wing area ratio of the flying squirrels is about 3.  For Yazirians with a mass of 50 kg and a wing area of 3 m^2, you get a ratio of 16.67.  This means that they are going to fall faster and at a steeper angle and require a lot more speed to sustain gliding.

Due to the mechanics of gliding, you have three forces, gravity, lift and drag.  Gravity pulls you down. Lift acts to propel you forward and lift you up opposing gravity, and drag acts to lift you up, also opposing gravity, and also retards the forward acceleration due to lift.  Now the force from gravity is just gravity times mass and is constant, regardless of what is going on.  The forces from lift and drag, however, are proportional to the square of the velocity and both have functional forms of F=0.5*p*A*C*v^2 where C is either the lift or drag coefficent.  So the faster you go the more lift and drag you have.  Practically, this means at the beginning of a glide, you have almost no lift and drag forces to oppose gravity and a yazirian falls just like a human, i.e. quickly.  It is only after falling a bit that the lift and drag forces actually start to help.

The other sticky question is what speed can a Yazirian safely land at?  The flying squirrels had speed of about 5m/s or about 11 mph.  Military paratroopers are trained to safely land at speeds of 6m/s.

So, if you assume a maximum landing speed of 6 m/s (about 13.5 mph), and you assume that a Yaz doesn't just drop into a glide but "pushes off" with an initial velocity of 3.5 m/s, thus getting a little bit more help from the lift of its wings, a wing area of 3 m^2, and drag and lift coefficents of 1 and 2.1 respectively you get the following table (assuming no change in atmospheric density).

 Gravity 
 Vertical distance 
 Horizontal distance 
 Time 
 1.0 1.44 m 2.00 m
 0.57 s
 0.9 1.60 m
 2.25 m
 0.64 s
 0.8 1.86 m
 2.60 m
 0.74 s
 0.7 2.18 m
 3.06 m
 0.87 s
 0.6 2.61 m
 3.70 m
 1.05 s

Now if you assume some sort of a "flare out" maneuver at the end, that serves to kill some of the horizontal velocity, and thus reduces the total velocity, you can extend this out.  If you assume that a gliding Yazirian has some way to kill half of its forward velocity at landing, you get the following distances before you hit the 6 m/s landing speed.

 Gravity 
 Vertical distance 
 Horizontal distance 
 Time 
 1.02.12 m
2.50 m
0.70 s
 0.92.44 m
2.86 m
0.80 s
 0.82.85 m
3.34 m
0.93 s
 0.73.48 m
4.06 m
1.12 s
 0.64.46 m
5.19 m
1.41 s

However, I don't see any reason a Yaririan can't make a very long sustained glide, especially on the lower gravity planets (although here we may want to look at the effect of decreased atmopheric pressure).  On the higher gravity planets the landing may be painful but I would think definitely survivable.  Here are some numbers:

 Gravity 
 Minium
Vertical distance 
 Horizontal distance
at vertical min. 
 Minimum
Time 
Total
Velocity
"Landing"
Velocity
Glide Ratio
(h to v)
 1.049.85 m
87.28 m
9.64 s
10.93 m/s
6.8 m/s
2.12
 0.949.68 m
87.48 m
10.16 s
10.37 m/s
6.45 m/s
2.12
 0.845.45 m
87.67 m
10.77 s
9.78 m/s
6.08 m/s
2.12
 0.744.09 m
77.16 m
10.21 s
 9.18 m/s
5.73 m/s
2.12
 0.636.52 m
62.54 m
9.07 s
 8.46 m/s
 5.33 m/s
2.12

So, if you assume the "flare out" maneuver at landing, you get the "Landing" velocity in the table.  Given that, and assuming a Yazirian has at least 50m of height, it should be able to glide indefinitely (or at least until its arms get tired).  On a 1.0 or 0.9 g planet I'd require a DEX check or take 1d10 points of damage since they are landing a bit fast (> 6 m/s) but otherwise the gliding is sustainable for long distances.  Also for the long glides it would be 2m horizontal distance traveld for every meter fallen vertically.

Decreasing the atmospheric pressure would do the following:
1) increase the height and time needed to get a sustainable glide
2) increase the terminal velocity and landing speed

Anyway, there's a bunch of food for thought.

Well, I've read this discussion with interest, but I don't think the conclusion gives the mathematically challenged like me a clear, concise Yazarian gliding rule to use.

I mean, I can pull things out of this....

So, if you assume the "flare out" maneuver at landing, you get the "Landing" velocity in the table.  Given that, and assuming a Yazirian has at least 50m of height, it should be able to glide indefinitely (or at least until its arms get tired).  On a 1.0 or 0.9 g planet I'd require a DEX check or take 1d10 points of damage since they are landing a bit fast (> 6 m/s) but otherwise the gliding is sustainable for long distances.  Also for the long glides it would be 2m horizontal distance traveld for every meter fallen vertically.

That's pretty clear.

I don't see any reason a Yaririan can't make a very long sustained glide, especially on the lower gravity planets (although here we may want to look at the effect of decreased atmopheric pressure).  On the higher gravity planets the landing may be painful but I would think definitely survivable.

Yes, that's clear too, but this isn't in a quick, "digestible" format.

It could be a useful story for Frontier Explorer.



Joe Cabadas

JCab747's picture
JCab747
February 19, 2018 - 10:23am
Were these original questions answered?

Question #1: Does the max glide distance make sense? if a yazirian jumped off an 100m building in 1.0G would he only glide 10 meters? Does he suddenly fall to the ground after 10m?

These are three questions, Jedion! But, they are related. I think the discussion answers this.


Question #2: how far can a yazirian glide in a turn? Or rather, at what speed does a yazirian glide?

I think this one is answered somewhat, but I think you need just one more iteration to make it a good, solid game rule.


Question #3:Then we have issue of what happens in a steep dive? What if the Yaz opts to drop more distance faster?

I don't believe this group of questions was answered... OK, I didn't read things as carefully as I should have. I'll reread the discussion again to make sure... I don't want my head lopped off like others on recent hovercycle discussions...

Question #4:Then we have what happens if a yaz tries to make an attack while gliding? 

I don't believe this one was answered either.

I can imagine that a Yazarian could make some kind of tackle attack, or if it is wearing something like shockgloves they might do a melee attack. Or if you have the infamous helmet rafflurs they might be able to do a ranged attack. 

I can't see them firing pistols or rifles with any accuracy while gliding... unless you have some sophisticated eye-tracking, targeting system with some kind of wrist-mounted weapon that you can trigger with your thoughts or the Zeb's jaw trigger.

I suppose they could hold some kind of rod in front of them -- holding with both hands -- while gliding. That could be some sort of melee weapon or a more sophisticated ranged weapon, but how useful would that be in a non-gliding situation?
Joe Cabadas

JCab747's picture
JCab747
February 19, 2018 - 10:52am
One other thought(s)...

Wouldn't the Yazarians have come up with something -- clothing/technology -- to extend their gliding abilities? Their ability to slow their descent? Such as parachutes?

Sure they could get a glijet, but since they are natural gliders, they ought to have a variety of accessories available to do the job. ... Jetboots, a small air-canister "thrust pack", membrane extensions... something!
Joe Cabadas

JCab747's picture
JCab747
February 19, 2018 - 8:00pm
JCab747 wrote:


Question #2: how far can a yazirian glide in a turn? Or rather, at what speed does a yazirian glide?


Question #3:Then we have issue of what happens in a steep dive? What if the Yaz opts to drop more distance faster?


OK, yes, these questions are addressed a bit, though I'm not sure if there were any definite conclusions...
Joe Cabadas

TerlObar's picture
TerlObar
February 21, 2018 - 7:13pm
Yeah.  I still have the spreadsheet I used to do the calculation.  It would make for a good article.  My data predates the Frontier Explorer's conception by more than a year. Smile

The bottom line was that short glides don't make sense but long ones do, which is kind of opposite what the rules state.  I'd have to think about it some more again to come up with some simple rule.
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JCab747's picture
JCab747
February 21, 2018 - 11:42pm
TerlObar wrote:
Yeah.  I still have the spreadsheet I used to do the calculation.  It would make for a good article.  My data predates the Frontier Explorer's conception by more than a year. Smile

The bottom line was that short glides don't make sense but long ones do, which is kind of opposite what the rules state.  I'd have to think about it some more again to come up with some simple rule.

Yeah!
Joe Cabadas

JCab747's picture
JCab747
March 7, 2018 - 5:35pm
I thought I would look up wingsuits in my quest to also develop some sort of diving rules for the game and came across this on Wikipedia:

As of 2010, there have been experimental powered wingsuits, often using small jet engines strapped to the feet[15] or a wingpack setup to allow for even greater horizontal speeds and even vertical ascent.

On 25 October 2005, in Lahti, Finland, Visa Parviainen jumped from a hot air balloon in a wingsuit with two small turbojet engines attached to his feet. The engines provided approximately 160 N (16 kgf, 35 lbf) of thrust each and ran on JET A-1 fuel. Parviainen achieved approximately 30 seconds of horizontal flight with no noticeable loss of altitude.[15][16] Parviainen continued jumping from hot air balloons and helicopters, including one for the Stunt Junkies program on Discovery Channel.[17]

Christian Stadler from Germany invented the "VegaV3 wingsuit system" that uses an electronic adjustable hydrogen peroxide rocket.[18] The rocket provides 1000 Newtons (100 kgf) of thrust and produces no flames or poisonous fumes. His first successful powered wingsuit jump was in 2007, when he reached horizontal speeds of over 255 km/h (160 mph).[19]

Using a powered wingpack, Yves Rossy became the first person to attain the maneuverability and flight distances of an aircraft, moving only his body for steering; his experimental wingpack, however, is not commercially viable because the required construction materials are prohibitively expensive. He took an eight-minute flight over the Swiss Alps.[20]


Joe Cabadas

JCab747's picture
JCab747
March 7, 2018 - 5:36pm
So, yes, Yazarians would have a bunch of different gliding gear available to them -- including jetboots!
Joe Cabadas

JCab747's picture
JCab747
March 7, 2018 - 5:39pm
Though I don't think they want to look like Condorman.

Image result for condorman
Joe Cabadas

JCab747's picture
JCab747
March 7, 2018 - 5:40pm
From How Stuff Works:

The average skydiver plummets towards the surface of the Earth at a rate of 120 mph (193 kph) and can soar horizontally at 30 to 60 mph (48 to 97 kph). Typical wingsuit flyers fall at a rate of 50 to 60 mph (81 to 97 kph) and can jet through the air at 70 to 90 mph (113 to 145 kph) [source: Birdman, Inc.]

Joe Cabadas

JCab747's picture
JCab747
March 7, 2018 - 5:42pm
Swiss wingsuit enthusiast Ueli "Sputnik" Gegenschatz currently holds the world record for the longest recorded wingsuit flight. On June 1, 2008, Gegenschatz exited an aircraft at an altitude of 15,000 feet (4,500 meters) and flew 11 miles (17.6 kilometers) over waters off the coast of Ireland at an average speed of 155 mph (250 kph) [source: The Daily Telegraph].
Joe Cabadas

JCab747's picture
JCab747
March 7, 2018 - 5:44pm
I think in the above cases, the wingsuited person used a parachute to slowdown. As TerlObar and others have stated, you go too fast, you go splat at the end of the glide.
Joe Cabadas

JCab747's picture
JCab747
March 8, 2018 - 3:55pm
Here's an effort to move this discussion along... or inch it along...

Yazarian Gliding. Yazarains can glide short distances using the membranes along their sides. Starting at no less than 10 meters above the ground, the character can glide 1 meter for every meter he is above the ground.

The maximum distance that the Yazarian can glide during a turn depends on the gravity of the planet, as shown in the Yazarian Gliding Table 1.

Yazarians cannot glide on planets with gravities below 0,6 G orabove 1 G

It actually takes a Yazarian about 3 seconds to glide from a height of 10 meters to the ground in 1.0 G gravity. During that time, theYazarian may be able to make a grappling attack at a target below or use asingle-hand based melee weapon – such as a knife – or shock gloves. In such a case, the character would receive the +20 percent modifier for attacking from above, but would suffer a -10 percent modifier for “running.” In the end, the character would have a +10 percent modifier.

Yazarian Gliding Table 2 is based on a discussion on the starfrontiers.us website about the Yazarian’s gliding ability. It provides somestatistics about how far a Yazarian can travel horizontally, how far they will drop, the minimum time it takes to travel that distance, etc.

Yazarian Gliding Table 2

 Gravity 

 Minimum
Vertical distance 

 Horizontal distance
at vertical min. 

 Minimum
Time 

Total
Velocity

"Landing"
Velocity

Glide Ratio
(h to v)

 1.0

49.85 m

87.28 m

9.64 s

10.93 m/s

6.8 m/s

2.12

 0.9

49.68 m

87.48 m

10.16 s

10.37 m/s

6.45 m/s

2.12

 0.8

45.45 m

87.67 m

10.77 s

9.78 m/s

6.08 m/s

2.12

 0.7

44.09 m

77.16 m

10.21 s

 9.18 m/s

5.73 m/s

2.12

 0.6

36.52 m

62.54 m

9.07 s

 8.46 m/s

 5.33 m/s

2.12

Note: This chart was created by Tom Stephens (TerlObar) and is based on a forum discussion about the Yazarian’s gliding ability.

  • m = meters
  • s = seconds
  • m/s = meters per second
  • h to v = horizontal to vertical distance.

If the Yazarian keeps gliding for a full 6-second combat turn (in a 1.0 G environment), the character would have traveled 22 meters horizontally and would have dropped 18 meters. At this point, a Yazarian does not need to have landed and could keep gliding – if there is room – or depending upon the distance to the surface, the character could elect to drop down from the remaining height. This would be treated like a fall, but treat the first 5 meters as if the character jumped. (See the Special Situations sub-section and the headings “Falling” and “Jumping”for more information).

At the end of two combat turns, a gliding Yazarian will have dropped 50 meters but can glide at about 90 meters horizontally in a straightline. For longer glides, assume the character can travel 2 meters horizontally for every meter dropped vertically. Unless the character uses some sort of parachute or other device to slow down at the end of a long dive on planets with gravities of 0.9 or 1.0, he must make a Dexterity check or take 1d10points of damage.

Joe Cabadas

JCab747's picture
JCab747
March 8, 2018 - 3:56pm
I'll find a different word to use than "treat," since that is the second time I used it in one paragragph...
Joe Cabadas

JCab747's picture
JCab747
February 10, 2019 - 2:59pm
I'm going to try to turn this discussion into an article and combine it with a discussion on diving.
Joe Cabadas

jedion357's picture
jedion357
February 10, 2019 - 5:40pm
JCab747 wrote:
I'm going to try to turn this discussion into an article and combine it with a discussion on diving.


copy that, have at it, anything I can do to support you? most likely I need to think about illustrations once the article is in.
Not sure if we used this one. in the zine as i just dont remember but something like this covers gliding for sure.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

JCab747's picture
JCab747
February 10, 2019 - 7:14pm
Artwork certainly helps.

If you can think of any other examples of how a Yazarian can turn, conduct aerial combat, etc.

Maybe some Yazarian gliding aids? Such as emergency parachutes? Or, jetboots for slowing down? 

How much weight can a Yazarian carry and glide?

Those are somethings I didn't cover in the draft thus far and an extra point of view would help.
Joe Cabadas

jedion357's picture
jedion357
February 10, 2019 - 7:59pm
JCab747 wrote:
Artwork certainly helps.

If you can think of any other examples of how a Yazarian can turn, conduct aerial combat, etc.

Maybe some Yazarian gliding aids? Such as emergency parachutes? Or, jetboots for slowing down? 

How much weight can a Yazarian carry and glide?

Those are somethings I didn't cover in the draft thus far and an extra point of view would help.


Jet boots are in a dragon article. dont know if they need a revisit to be updated? or can be used just as is.
yazirian zamra honor blade (polyhedron or ares article) had a gliding duel feature to it. that said the yazirian gliding equipment I would want for my character would the disc grenade bandolier from a Minzii market place feature I did in FE oh yeah and a stock of disc grenades jsut because.

as for chutes, I just see the yazirians as, "Parachutes? We dont need no stinking parachutes." sort of attitude. but a mini chute that would let them employ their already increased drag and land safely after a long glide that excedes their max glide path is kind of obvious but I would also rule that a yazirian knows by instinct if a glide is safe for him to attempt in the current gravity- its sort of bred into them. and if not then a chronocom glide comp which lets a yazirian check a glide. Alternately they instinctively know how to judge glide distance in the gravity they were born to and grew up in but not so much in other gravities- this means a LOG check or use a chroncom glide comp.

I like the Chronocom Glide comp, calculates a safe glide path costs 50 cr more has all the other features of a chroncom.


The tumbling feature of martial arts is probably a good subskill to have for a yazirian so he can push the bounds of gliding or simply make it smart less when he goes too far.


I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

jedion357's picture
jedion357
February 10, 2019 - 8:29pm
another illustration, think we used it in the zine so it would be a recycle

I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

JCab747's picture
JCab747
February 11, 2019 - 6:06am
Yep, that's a good one.
Joe Cabadas

jedion357's picture
jedion357
February 13, 2019 - 5:10pm
Work in progress
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

JCab747's picture
JCab747
February 13, 2019 - 5:15pm
Yep, that would help illustrate it.
Joe Cabadas

jedion357's picture
jedion357
February 13, 2019 - 10:12pm
a little pen, ink and watercolor
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

JCab747's picture
JCab747
February 13, 2019 - 10:51pm
much better!
Joe Cabadas

jedion357's picture
jedion357
February 14, 2019 - 10:25am
JCab747 wrote:
much better!


I'm actually "baking" the image in GIMP 2 right now so the finished product will be more refined.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

Shadow Shack's picture
Shadow Shack
March 3, 2019 - 9:11am
Great work on the gliding Yaz. It reminds me of a pose Rob Liefeld was famous for in comics.

Related image

I like this image, gonna have to see about using the pose here.
I'm not overly fond of Zeb's Guide...nor do I have any qualms stating why. Tongue out

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