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noamineo

Looking for some ideas

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Hi folks,

 

I am doing some research for a novel and am looking for assistance crafting a skydiving scene. The set up for it is that the characters are on a military transport plane heading for a remote expedition. This takes place in a constructed world, so no need for details on specific aircraft models/designations/etc. The original plan had been for the airplane to land on a waiting aircraft carrier, but upon arrival the weather is too bad for a landing. The only choice is to parachute onto a nearby landmass.

Of the characters, one is an experienced paratrooper, one has spent a few afternoons at a military jump school and done a single training jump tethered to an instructor. The other two have never jumped at all(one of them doesn’t even know what a parachute is).

Obviously a jump under such circumstances is a terrible idea and obscenely dangerous, and no sane skydiver would consider it, but it’s kind of necessary for the plot for various reasons I won’t get into. The novel is a fantasy/sci-fi type world, but I like to stay grounded in physics. Aside from the “the characters are idiots for trying this” aspect, I’d like to make the scene realistic.

 

Details I am looking for:

*A good altitude for making a jump like this

*Some guidance in crafting a good scene, including a description of what its like to jump in bad weather

*A little information on gear(at the very least, fact-checking what I have)

 

Then the main challenge: something needs to go wrong during the jump, but not fatally so. I’d really like some ideas for what can go wrong but still be recovered from. Minor injuries are fine.

Since they are jumping from a military plane with paratrooper rigs, someone with experience in that area would be helpful, but really just any basic suggestions would be great!

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(edited)
1 hour ago, noamineo said:

Then the main challenge: something needs to go wrong during the jump,

LOL... oh yeah, something IS going to go wrong :)

I would recommend you stage it as a hop and pop to limit the free fall time for the rookies. Maybe even a static line since it's military. 

Edited by Phillbo

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I'll ask a few questions to help others because depending on them it will change a lot

Do you drop them from low altitude or high up?

Parachute type round or square? You said paratrooper so I assume a round one
Military use both depending on specialty and exit altitude.
Round: exit altitude around 1250'
Square: anywhere between 2500' to 30000' for the main, emergency is 1500' min deploying reserve

Weather
As a civilian, we're not allowed to jump in bad weather so I can't help there. I only know it sucks being hit by ice during the way down.
Winds depend on your licence, in Canada
A,B = 18mph
C,D = 25mph
I'll assume that they'll jump military parachute so winds can't really go more than this with a square and I have no clue with a round.

Gear and malfunction:
Depends on the above, I can't help you with a round

As for the 2 characters that never jumped before, they won't get out of the plane without a good push from someone

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Thank you for the response! I am seeing just how much I DON'T know about skydiving! (which is why I do research like this, lol).

In this case I am thinking round parachutes as they are bail-out chutes for the plane(jumping was never "Plan A" for this mission). Thank you for the note on the ice, that will be good!

Definitely going to be a "hop and pop" - that was already the plan, but thank you for the terminology! 

Altitude - yeah, I had NO clue about that. I'd like to drop them fairly low but there needs to be enough time for things to go badly during the fall. Plus they'd want enough time to use a reserve-chute for safety margin. I am thinking around 1500, but don't know much.

 

And yes, already planning to have the 2 novices get pushed out, figured that was a must.

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As I said I don't know rounds enough to help.

1500' is way low to plan for a reserve deployment, I don't know if you can deploy your reserve with the main at the same time if there's a malfunction with rounds. A lot of skydivers have a hard deck of 2000' meaning that if they can't get the main working, you cut it loose and activate your reserve. 

Main deployment and hard deck decision is a stack of altitude consideration from the ground up at terminal velocity. Altitude of AAD (automatic activation device) is fixed on this example but people are now raising it to account for other orientation than belly.
900' : AAD activation altitude = 900'
1500': Safety margin to spot a landing= 600'
1800': Reserve deployment = 300'
2000': Safety margin for reaction time to cut away = 200'
3500': Main deployment = 500-800' + safety margin to hard deck
These are consideration to have an optimum landing while dealing with a mess over your head.

I would plan for a brain lock after being pushed out, no pull and AAD save at around 900'
AAD's are armed around 1500', below that, they won't arm and won't fire to save you

Check this, AAD save at 900' from terminal. There is no safety margin when they land. But your situation will be different with a hop and pop

 

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Awesome, thank you! Some good stuff for me to chew on.

Going back over my notes it appears they actually are using square rigs. Went back and checked a scene earlier... might have some other questions on that, too.

 

You mentioned earlier 25mph being the maximum(i assume SAFE) wind speed. What's the maximum wind speed at which it goes from "unsafe" to "suicidal" for a square rig?

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Deployment altitude depends upon velocity vector. ...  er .... which direction you are travelling and how fast.

If jumping from a military transport airplane you can take jump altitude down to 500 - 300 feet (150 - 100 metres) above ground. If the airplane is travelling 100 - 130 knots (160 - 200 kilometres per hour) horizontally, your parachute will open with hardly any altitude loss. If you pull your ripcord in the doorway, your parachute will open with hardly any altitude loss. That gives you less than a 30 second parachute ride.

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noamineo, skydivers under normal conditions land upwind. Canopy has built-in speed which is usually about 15 mph forward. That means if there is no wind at all, these skydivers have about 15 mph of ground speed before touch down.

During *regular* upwind landing conditions, if the wind is blowing at 15 mph - the same skydivers have about 0 mph ground speed before touch down. Simply because they land upwind so the speed of wind + speed of the canopy cancel out. 

Skydiving canopy behaves like wing of the airplane. In order to safely execute landing, skydiver has to flare right before touching down. Flare is when skydiver pulls both toggles (toggles are kept in hands) all the way down to the knees level. When flare occurs the canopy's tail is deflected which causes more lift and slows down the forward speed. That allows gentle landings.

Now let's talk about somebody who does that for the first time in their life and they don't know what they are doing. If the person lands downwind at 15 mph wind (their ground speed at that point would be about 30 mph) and DOES NOT flare, they are gonna hit the ground hard. You can think of standing at the tailgate of the pickup truck, facing the direction of the drive, driving 30 mph and you just jump back on the ground. You are very likely to break your legs. 

Something like below, but DRIVING 30mph. 

Now let's talk about somebody doing that at even higher wind with obstacles and uneven ground...

 

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(edited)

noamineo, also, common injury & fatality cause is so called low turn. If you pay attention, the way skydiving canopy turns is by diving. 

For example like this one:

Doesn't look that scary, right? Weather is nice, he's got fully functioning parachute. Small mistake all of a sudden causes very serious health consequences. 

Edited by CoolBeans

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Wind speed is pretty important. Lower is better.

Rounds have very little 'forward' speed. Squares (under specific circumstances and in very expert hands) can go much faster. 
But the problems is when you land. If a round is going 5 or 6 mph forward, a 20 mph wind would mean it's going 14 or 15 backwards, or 25 or 26 forwards (and it's not unusual for a novice to 'freeze up' on landing and do nothing). So the landing would be the rough equivalent of jumping from a moving car at slower city street speeds. There's also the issue of the canopy catching the wind once the jumper is down. Being dragged sucks. And can be dangerous.

Paratroopers practice a "Parachute Landing Fall" (PLF) a zillion times during training. They'll jump in some pretty hairy conditions, so they need to be able to land without major injury in all sorts of situations. Even then, the military expects that a certain percentage of the troops will be injured and incapacitated during the drop. 

A few more thoughts:

Gear - For a novice, a static line jump would be simplest and "most accomplishable" (if that's a real word). That's the type of jump where a line is attached to the plane, and it opens the container (pack) as the jumper falls away. Some just pull the pin and open it, others extract the deployment bag (the bag that the canopy is packed into), pull it to line stretch and pull the bag off. There are both round and square static line rigs. However, for a 'bailout rig' (emergency parachute), those usually aren't static line, they have a ripcord that needs to be pulled to open it. The problem with using that kind is that the jumper needs to find and pull the ripcord. Which is a lot harder than it sounds for a first timer who is 'plummeting towards certain death'. Ya got an 'expendable' character who can be on the plane and not survive the jump? (sort of kidding, but not completely)
Most bail out rigs are rounds. There are square ones out there, but they are not typical. Generally used by jump pilots who are also skydivers. Steering a round is pretty simple (pull left, go left) but landing one safely takes some skill & practice.

 

Altitude - The military will make combat jumps as low a 800 ft or so. For those jumps, the time to recognize and react to a malfunction (get the reserve out) is extremely short. Sport jumpers will do static lines from 4500 or so. Lots more time to deal with anything that goes wrong. For licensed sport jumpers, the 'minimum pack opening altitude' is 3000' or 2500', depending on license level. Most jumpers have a decision altitude (sometimes called a 'hard deck') of 2000' or so. That's the lowest altitude they will continue to try to deal with a malfunction before cutting the main away and deploying the reserve. Sport jumpers are often doing stuff in freefall, so we get out at upwards of 14,000' and fall until deployment altitude. There's rules on oxygen use at higher altitudes. Some jumpers want to focus on canopy skills, so they do a 'Hop & Pop', getting out lower and deploying immediately. A couple of those are required for a student to be licensed. It's rather funny to watch a student who has never gotten out below 10,000' to look down from 3500 and say "it's so low". 
For your scene, a static line jump from 4000' or so or a H&P from 5000' would be reasonable. 

Other weather issues - If it's too nasty to land a plane, it's too nasty to jump. In fact, a basic instrument landing is doable in weather far worse than a parachute jump. It's somewhat plausible for them to not be able to find and land on a carrier, depending on the technology on both the boat & plane. Or maybe the weather at sea is crap and it's better over land. 
Ice was mentioned. Rain hurts like all hell too. The joke is that when we fall down, we are hitting the tops of the raindrops. You know, the pointy end(reality is that they are round, it's just the impact velocity that hurts). 

Clouds are a big 'no-no' in jumping, at least in the US. You can't see what's on the other side of them. Colliding with a plane or another jumper (free fall or under canopy) is a really bad thing. You also can't see the landing area. There was an incident in Ohio back in the 60s where a load of jumpers was accidentally dropped a few miles out over Lake Erie. The air traffic controller mis-identified the plane and thought they were over the DZ. Most of the jumpers drowned. GPS or similar can be of help in that sort of situation, but it's not perfect.

 

Stuff going wrong - There's a few different malfunctions, where the parachute opens, but doesn't fly properly. The gear is designed that pulling the cutaway handle releases the main parachute and then the reserve handle is pulled to deploy that (there's an RSL or MARD that does it automatically, and there's also an AAD that senses fall speed and altitude and deploys the reserve at the last second). Some mals are gentle (lineover, where one of the 'strings' is looped over the canopy fabric), some are not (spinning linetwists can get very 'interesting'). 

 

Last, you said one character was an experienced paratrooper and the other had spend time at a military training school and done a jump tethered to an instructor.
Paratroopers are almost exclusively static line jumpers. Military freefall is a thing, but it's a specialty. Mostly for the 'spec-ops' types. Tandems (tethered to an instructor) are almost exclusively civilian. The military does them, but those are almost always "show" jumps. Taking George Bush or the Dolphins cheerleaders or that sort of thing. Even the MFF guys do what called "AFF" in the sport world.

 

I don't know where you are, but you are only going to get limited info on here. Only so much can be conveyed via posting.
Your best bet would be to go out to a DZ. Maybe do a jump. 
Most of us love the sport and it's way, way, waaaaaay easier to get us started talking about it than it is to stop us. If you go at the end of the day, there's usually a bunch of jumpers sitting around, drinking beer and swapping stories. Take a case of good beer and ask for advice. 
Seeing the way jumping is often portrayed in books & movies annoys us. The fact that an author is trying to get his basic facts right will encourage some of us to help.
 

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As to the type of parachute. Almost with out exception emergency bail out rigs are round canopies. Recently people have been putting large square canopies in some pilot rigs but this is almost always jump plane pilots at civilian drop zones who are them selves jumpers. Pilots and air crew are rarely jumpers unless it's a hobby for them. I'm not aware of any pilot/aircrew/bail out rigs in the military with square canopies, for good reason, round canopies do not require any input to land so untrained, non jumpers, or unconscious individuals can use them. A square canopy you have to actually unstow the breaks, stear the canopy, and flair it to land with out hurting your self. If you want to see the kinds of containers that might be used look up BA-22 parachute. That is a fairly standard bail out rig that some one might wear moving about in a plane. It's some what heavy and bulky. It can tolerate higher speed deployments. It uses a quarter bag as a kind of diaper holding the bottom half of the canopy closed till the lines are deployed. The canopy is a C-9, One of the toughest canopies ever built, the lines run continuously over the top of the canopy forming a net supporting the canopy. It's some thing you would see in early ejection seats before the parachute was built into the chair. On larger aircraft it allowed them to move around. 

 

Bad weather can be scary. We've all been there. In the US there is no wind regulation other then your judgement. We've all tried to get that last jump in before the front rolls in. Every one has at some point landed, even with a square, backing up in forty mph winds. Getting drug is actually very dangerous. It's especially dangerous under a round canopy. There are people that have been drug to death. People have been knocked unconscious on landing or while being drug. They can strike a object like a rock or tree stump and break their neck. Those are real events. The containers generally have releases on the risers. They are primarily there as anti drag devices or to get lose, like to get out of a tree. Look up, capewell parachute release, as an example. You open the cover and that loop of cable pops out where you can grab it. You put your thumb through the loop and pull forwards releasing a lever. As you pull forwards and down the lever moves a slide that locks the bottom of the capwell on the end of the riser into the peace on the harness it flips out ward releasing the hook on the top and that riser goes away. You only need to release one set of risers, on the right or left, to fully collapse the canopy and stop your self from being drug. I've landed, with a square, in 60 mph winds. It's scary. As it happens I did not have any form of release on that rig. I was drug for half a mile across the sea ice before I could get the canopy collapsed. Found it. The quality on You tube does not do it justice. I swear the wind wasn't that bad at the top. It's a weather thing up there where you get an out flow of air through the fiords  It can be blowing 50+ at the bottom. At one point you see the corner of my canopy come down level with the horizon. That was not me making a turn. That was when I passed through the wind sheer and found out that I was in trouble. I tried to hide it but inside I was crying like a little girl. There is another even better video from Norway but I have no idea how to find it. It's an out side video of a guy having the same thing happen. Another famous historical event happened when a guy bailed out of a plane over a thunder storm. His parachute opened but he was sucked back up into the thunder storm. You should look it up if you want to know what jumping in a storm is like. I can tell you that rain stings, sleet fucking hurts, I don't know if you could survive hail. 

 

https://www.google.com/search?biw=1920&bih=937&tbm=isch&sa=1&ei=JmQ7XdKICsresAXwyb_wCw&q=ba-22+parachute&oq=ba-22+parachute&gs_l=img.3..35i39.10989.12020..12591...0.0..0.62.120.2......0....1..gws-wiz-img.......0i7i30.aiErpGMTluc&ved=0ahUKEwjSs53nt9PjAhVKL6wKHfDkD74Q4dUDCAY&uact=5

 

https://www.google.com/search?q=capewell+parachute+release&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjD-Kr2vtPjAhVLOKwKHV2JC_cQ_AUIEygD&biw=1920&bih=937

 

https://loa-shared.s3.amazonaws.com/static/pdf/Rankin_Man_Thunder.pdf

 

 

Lee

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32 minutes ago, wolfriverjoe said:

Seeing the way jumping is often portrayed in books & movies annoys us. The fact that an author is trying to get his basic facts right will encourage some of us to help.

^ This is exactly why I come on forums for advice like this. I may be writing a ridiculous sci-fi/fantasy high adventure novel, but if I'm portraying something real like skydiving, I think its a lot more fun for the reader if I portray it accurately. Plus, on the off chance an actual skydiver reads it, I'd like to make them smile.

 

 

When I outlined this scene originally the plan was for good weather and the jump to go off without a hitch... but where's the fun in that? To help understand the mood without going into the massive backstory of what is already a 130,000 word novel, I'll tell you that a big part of this scene is demonstrating how the protagonist nearly gets all her friends killed with her stupid decision. I am trying to set the stage for a jump that is risky, but not just suicide.

Working on advice in this thread, the carrier is several miles out to sea. The weather is still ok for launching helicopters and fighters, the transport plane is bigger and needs better conditioners(fun fact: landing an airplane on an aircraft carrier at night is the hardest thing humans do on a regular basis. That's not relevant, I just think it's cool)

Adding to the time constraint, the airplane needs to turn around very soon in order to have enough fuel to make it to a landing strip(they are very far off the beaten path), so when they make the decision to jump there's not a lot of time to stop and argue about it.

The jump itself will be done with round rigs(makes more sense after some of the advice I've got here) from about 4,000ft(4300, in case anyone cares). They discuss trying to rig a static line but again there are time constraints(and poor decision-making) at play. The storm front is fast approaching and the pilots are ansty(the airplane actually ends up crashing, but that's not until after our protagonists are on the ground).

 

So far my plan is:

*Soldier - ends up landing in the ocean and nearly drowns(and nearly dies of hypothermia, bad day)

*main protagonist(who's terrible idea this was) ends up getting her shoulder dislocated and beaten up pretty badly when she's dragged on landing

Our "first timers" almost end up staying on the airplane, but one of them looses his balance and knocks himself and the other out the door.

*one of the never before skydived people "locks up" and ends up being "saved" by the AAD("Saved" is in quotes because he still ends up in a thicket of trees. He's not badly injured for plot-related reasons(superhuman strength and toughness) but is badly traumatized by the experience).

*the last character by some ridiculous stroke of luck lands totally safely. My idea was that some sort of freak confluence of winds converge to make her landing quite comfortable. This might be stretching the bonds of realism some but in context it will be funny(the entire rest of her character arc for this half of the book is a traveling shit-show, so this is the ONE thing that goes right)

 

So, let me ask two things:

1. What is the highest reasonable air speed all of this could happen in? High enough to make one of you say "Oh shit!" but not "This is stupid, the writer is an idiot".

2. If you needed to give someone who'd never seen a parachute before a 30-second crash course in skydiving, what would you tell them?

 

Thank you all again for your wonderful input! I may be back in a couple of days soliciting volunteers to read over what I come up with.

 

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Actually, that doesn't sound all that unrealistic.

 

Something that I missed in my post was that sport rigs have reserves. Bailout rigs do notSo if they are using those, a canopy mal would be really really bad. And cutting away, going to reserve isn't an option.

To my knowledge, most bailout rigs do not come with AADs. Only sport rigs. So that may not work. One alternative is to have the character not be able to find the handle until the last second. One thing we are taught is to find the main lift web (vertical harness strap) and follow that up to the handle. They would have to be someone who can think under pressure and remember stuff when it really counts. Lots of old school, Depression era barnstormers went in 'no-pull' and were found with torn up jumpsuit knees. A couple who had close calls recounted that they couldn't find their ripcord and were grabbing anything and everything. Including the knee area of the suit. Jumpers went out in a 'tuck' position back then.

 

But, to answer your second question first:

I'd tell the poor sap to go out the door with their hand on the ripcord handle and to pull right out of the door. When they pull, fling both arms out as far and high as they can. As far back too. That would put them in the old 'student X man' arch position. I'd also tell them to 'tuck and roll' when they land. A judo fall for someone with that sort of training. We call it a PLF. 

Landing in trees is usually pretty bad, but a good old 'blackberry bramble' is just really annoying and scratchy. It will also cushion the landing some. 

Landings can be largely a matter of luck. A good gust or calm at the right (or wrong) time, landing in a sheltered area (lee) can help, although turbulence from obstacles is a large concern.

Any winds above 15 mph or so would make this sketchy. Anything above 20 would be beyond reality. Especially with a round.

 

And I agree that carrier landings, especially at night, are one of the most difficult and dangerous things in the world. But also cool as hell. 

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There used to be a guy on here and on basejumper.com More active as a base jumper, you might have better luck reaching him there. He used to be a navel aviator, I think he flew f-14's. I'm trying to remember his screen name, I think it was flydive. Might be this guy.

 

https://www.dropzone.com/profile/2795-flydive/

 

http://www.basejumper.com/cgi-bin/forum/gforum.cgi?username=flydive;

 

He could give you some very good input on weather limitations for launching and recovering aircraft. I think they might be able to launch in much worse conditions then they could recover in. I don't it's implausible that a long flight to this location might result in them arriving in worsening weather and unable to land but that is some thing that they would be trying to avoid communicating in route as they pass possible alternates. A pilot would very much not want to box him self in to a forced landing with out fuel to reach an alternate landing site. the worsening weather might make that alternate more difficult to reach. He might now be bucking a head wind. 

 

Landing in the water is a scary thing. There is almost no steering with a non modified round. An experienced jumper can try to "slip it" Pulling on two risers, say the two right risers, to try to make it slip right. Limited effectiveness. Landing in the water even a short distance can be life threatening in even mildly cold weather. Yes people die that way. Round canopies can drag you in water just like they do on land. Some parachutes used in the navy have what is called water pockets on them. It's a peace of fabric sewn to every other goar, the triangle slices of the parachute between the lines. It's sewn on three edges leaving the top open like a big pocket. They catch in the water when you are being drug in the water in high winds. The bottom edge of the canopy is held and the air spills out as the canopy rolls out flat onto the water and deflates. So that is very plausible that the most experienced person would be blown into the water, land, be drug, have the canopy collapse, get cut away, barely make it to shore and be in very deep trouble with hypothermia.

 

A dislocated shoulder is exactly the sort of injury that you would expect from a hard landing/dragging event. This could happen even to an experienced jumper and it's the sort of thing that you would expect to happen to some one untrained. 

 

Falling out of the plane is not a ridicules idea. Under normal circumstances I would say that that is stupid but in weather, even moderate turbulence, you can literally have any thing not strapped down, ex. people, bouncing off the ceiling. Particularly at the back of the plane away from the CG that tail can move all around. You could find your self bounced off the ceiling, swotted by the far wall and ejected out the door. I've seen pilots do it on purpose. Some one he does not like or wants to fuck with is lounging by the open door, best spot on a hot day. Push on the yoke to unload him, make him weightless, and a hard kick on the rudder and out he goes. Funny as shit especially if he is asleep. It's what passes for humor in skydiving. It's dangerous to fall asleep at the drop zone. 

 

With the almost complete lack of control of an unmodified round a tree landing makes perfect sense. Trees look soft and fluffy but they have these hard things hidden in them called branches. You really want to keep your legs together and cover your face with your arms keeping them in tight to protect your neck and arm pits. 

 

A basic course... Try to get them to exit with both hands on the silver handle. Count to three, they do this in about half a second, pull down and away to full arm length. Keep feet and legs together. If it were windy I would brief them on how the release worked. squeeze the feet and knees together on landing. Keep them slightly bent, do not lock them straight. Hold on to the risers, it will help to keep the from reaching out for the ground, good way to break or dislocate your arm. Once you hit the ground your whole focus should be on getting that riser lose. Open the cover. Hook that ring and pull.

 

The reality is that they will not exit stable. They will be tumbling ass over teakettle. No point on focusing on any thing but getting that handle pulled and minimizing the parts of the body sticking out for the canopy to wrap around as they tumble. The second they exit they will be blind and disoriented. Rain at that speed is like being sand blasted. Once the canopy gets open every thing gets calm or would normally. You don't feel the wind you are just drifting with it, but wind gust can be violent. The guy in the book was in cloud but describes the violence of the turbulence. It may have been his vertigo but he thinks that at one point the canopy was beneath him. That was actually inside the storm. Normally it's not that bad. It's quiet, peaceful. Until the thunder which can be loud. But when you look down you will see the ground going by under you at an alarming rate. Gust feel like they are pulling the canopy to the side and then letting it go, causing you to swing and oscillate. The canopy osculates. As you land in high winds you're traveling sidewase. This actually helps your landing. It will take your feet out from under you and roll you out sidewase on the ground. I think PLF's are much easier under a round with a little wind. I generally turn sidewase to the wind to help with a nice right or left PLF. But with a canopy like this it's random. Face, ass, side roll the dice. 

 

And I like the idea of the one idiot coming away unscathed. That's very real. If you catch the right gust, hit at just the right point on the oscillation, you can almost stand it up. He'll fall over in this wind but there is always one guy like that. 

 

How high of winds? I don't think there is really a limit. I would not chose to jump a round in more then 12 mph, I like rounds, strange that way. This is not really recreational. It might be 30 mph now but 50 when the front hits. I think a better question is what wind and sea state can they not land in. It's a crazy plan to begin with, I assume they are being forced into this.

Lee 

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A hurricane  can dramatically increase tension. The aircraft carrier deck is rolling 45 degrees to the side. Exhausted sailors bounce off bulkheads ....., etc. Seas will need 4 or 6 days to calm enough for the cargo plane to land. Fighters might be able to land in rougher seas because their higher/heavier wing-loading makes they less affected by turbulence but no sane pilot wants to do near a hurricane.

Perhaps our heroes are already in cloud when they blunder into the hurricane.

Flying through the hurricane bounces them around inside the airplane .... breaking arms, etc. ....  if they release seatbelts too early. 

Flying out of cloud - into the sunny eye - gives a moment of emotional relief but it also applies time pressure. They only have a minute or two to exit. If the last person hesitates and exits late, he will descend into the hurricane wall.

In that scenario, I would take exit altitude down as low as 500 feet (150 metres) to minimize the risk of missing the target and reduce exposure time to winds.

If a junior jumper hesitated, I would “muscle” him to the door and pull his ripcord as I shove him out the door .... easier to do if he/she is unconscious.

The primary reason that we do not drop students in winds exceeding 15 knots is the risk of dragging after landing.

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Just for the record:

Despite his abysmal spelling, Lee is probably the smartest guy on here. He's currently rigging recovery parachutes for a rocket program. So he's really a 'rocket scientist'. 

The story he's mentioned is called "The Man Who Rode the Thunder."

Ltc William Rankin was in an F-8 Crusader, going over the top of a thunderhead at 47000' when his engine quit and caught fire. The APU failed (handle broke off in his hand), so he had no hydraulic power to control the plane. It was not a survivable situation (and he probably could not have ejected safely in a very short time), so he ejected directly over the storm. 

Due to the updrafts in a thunderstorm, he spend quite a while going up and down inside it. 

He may have been disoriented, or he may have actually pendulumed up and over the inflated canopy. 

Absolutely fascinating story. All the more so because it was true. I read the book back in High School.

https://aviationhumor.net/the-man-who-rode-the-thunder/

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Thank you all again for your fantastic and highly detailed assistance! 

I have finished the rough of the segment, and will be doing ongoing revisions; but for now I think it's a pretty good start. I ended up leaving a few details ambiguous and mainly following the protagonist. I think I've got all the details down pretty well, but I wouldn't mind if one or two of you could volunteer to read through the scene and give me some feedback. Its 8 pages, about 3700 words, and I could use some ideas on drawing out the actual jump experiences and making them sound more terrifying and dramatic. If anyone is interested, please message me and we can discuss.

 

As a side note, I had heard the story of Lt. William Rankin, one of those awesome tails of survival I so dearly love. The fact that its true just makes it even better! I always enjoy my brief flirtations with communities like this; makes me wonder why more writers don't do what I do. No matter what you're writing, there's a community of enthusiasts out there who are experts on the subject and would love to help you bring some accuracy and realism to your project. Even if it involves dragons.

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If this is put together as an impromptu thing then rule out AAD's unless you have a reason to contrive the parachute gear having been put on the plane in the expectation that it would be used.  Or want to go through extra steps to contrive a way to jerry rig it.

You set an AAD on the ground - the problem is it works on pressure - the point it's turned on it calibrates itself to thinking it's on the ground.  If you do it at 12,000ft and then exit, it's going to think it's underground and not work.  I suppose you could descend to 1000ft, turn on the AAD, then climb and then exit and accept that instead of firing at circa 750ft it'll fire at more like 1750ft - might work if you're writing a techno thriller.  Adds more steps and further peril I suppose.

Note AAD's will activate the reserve, not the main and will only be in military or sport gear - a bailout rig will not have one and will have only a single parachute. 

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2 minutes ago, RiggerLee said:

There is a Air Crew Cypres. You find it in emergency rigs, single canopy rigs for pilots and flight crew, mostly military or contractors. 

 

http://www.ssk.us/EAC_20031202.pdf

 

Lee

I had forgotten about that version. 

It seems like it would be prone to activating before leaving the aircraft, as there can be significant time after the pin is pulled before exiting.

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You won't see a lot of them. Notice they talk about a pin being pulled. There were some early ejection seats where the parachute was still worn on the back separate from the seat, typically BA-22's,  that had low altitude lanyards and others where they had AAD's that would go off a timer as well as altitude... This was kind of in the same vane. I think it was supposed to be simi compatible with some of these older systems or at least in the same vain. So when you separated from the seat it would turn on when the pin was pulled. Or you could walk around in it and pull the knob before you jump out. If he can't find the handle... I've only run into a few over the years but it's some thing you will see in an air crew rig like you might find on such a plane as this. Load masters that are working in the back of a plane doing air drops wear them. I've seen them used out in Eloy. It's a thing, you just don't see it in skydiving. 

 

Lee

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