Forums: Skydiving Disciplines: Swooping and Canopy Control:
Does it concern anyone that . . .

 

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Premier skybytch  (D License)

Dec 15, 2001, 8:19 AM
Post #76 of 93 (1564 views)
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As CN#1 you'd think I would be all over this thread.... I agree with Chuck, this is a good forum and the questions are gonna be from all over the place.

Swooping is the way many/most jumpers want to land. Educating jumpers, especially novice jumpers, in the safest swoop landing techniques might keep someone alive, therefore imho it is worthwhile.

Re: student wingloading. I'm all for putting capable, well trained students on zp canopies loaded at 1.0:1-ish, but I feel that 1.2:1 on a first jumper is excessive, just as .4-.5:1 is way too light. There's no way to predict how a first jumper is going to perform under canopy. I've seen students do great in the FJC then blank out under canopy and forget to flare, ending their first jumps with broken ankles even on big F111 canopies.

I think a first jumper on a 1.2 wingloading is being put at a substantially higher amount of risk than the first jumper on a .8 wingloading. What bothers me about that is that the first jumper at 1.2 doesn't know about the increased risk he's being put under. And personally, I wouldn't want to share the airspace with that first jumper at 1.2, again because there's no way to predict what he's going to do.

pull and flare,
lisa


Zennie

Dec 15, 2001, 11:15 AM
Post #77 of 93 (1554 views)
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In reply to:
I think a first jumper on a 1.2 wingloading is being put at a substantially higher amount of risk than the first jumper on a .8 wingloading.
Absolutely agree. People may be misunderstanding what "the Houston Contingent" was driving at. I'll just give my experience as an example of something that I think is a good compromise. I weigh about 185-190 out the door. My first jump was on a Sabre 190. After about 5 jumps on that I started easing myself into a Sabre 170. Did the 170 for about 20-ish jumps after that and started easing myself into a Sabre 150, which was what people (instructors & experienced jumpers) were recommending I buy. I've put around 150 jumps on the 150 and I'm now demoing 135s and have pretty much settled on a Cobalt (though I have yet to demo a Crossfire or Stiletto). So my "wingloading progression" as it were was:

1-5: ~1.0
6-20: ~1.1
20-175: ~1.26

I won't have my new canopy for probably a few months, so my guess is I won't be flying 1.4 until around the 250-275 jump mark.

This still may be considered going too fast by some folks, but I have yet to make a downsize decision without discussing it at length with several high-number jumpers first.

My point is, however, I don't think anybody here would advocate a 1.2 wingloading for the first time jumper. The question becomes whether it maybe appropriate for a low-timer. Again it depends on the person. Some pilots probably shouldn't, others, it's OK.

The big thing is talking and listening to experienced canopy pilots who are familiar with your flying. If they aren't ask them to watch a few of your aproaches & landings.

"Zero Tolerance: the politically correct term for zero thought, zero common sense."


Slappie  (A 123)

Dec 16, 2001, 12:37 PM
Post #78 of 93 (1511 views)
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Here here, thanks Zennie... You said what I've been trying to say Smile I feel so DuH! now Laugh

My New Website with 24hr Chat


AggieDave  (D License)

Dec 16, 2001, 8:46 PM
Post #79 of 93 (1474 views)
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So I just had some brake lines sewn onto a drogue-chute, will that work? I'm about 240lbs out the door...

Laugh

AggieDave '02
-------------
Blue Skies and Gig'em Ags!
BTHO t.u.


Slappie  (A 123)

Dec 17, 2001, 12:14 PM
Post #80 of 93 (1419 views)
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AggieDave only if I can video it!!

My New Website with 24hr Chat


Spectrejumper  (D 23312)

Dec 17, 2001, 6:11 PM
Post #81 of 93 (1386 views)
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In reply to:
This still may be considered going too fast by some folks, but I have yet to make a downsize decision without discussing it at length with several high-number jumpers first.

My point is, however, I don't think anybody here would advocate a 1.2 wingloading for the first time jumper. The question becomes whether it maybe appropriate for a low-timer. Again it depends on the person. Some pilots probably shouldn't, others, it's OK.

The big thing is talking and listening to experienced canopy pilots who are familiar with your flying. If they aren't ask them to watch a few of your aproaches & landings.
That's a great plan, if all your landings are going to be on the DZ in good conditions. The problems start when you get into one of those "oh shit" situations. There have been at least two fatalities this year where low time jumpers made poor decisions on off DZ landings. Jump numbers are no guarantee, but more experience might have lessened the pucker factor and helped these guys make better decisions.
I don't want to come off as some kind of ultra-conservative safety nazi, in this or any of my other posts. I just hate reading about fellow jumpers getting injured or killed. I think somebody else said this recently, but it bears repeating: you've got your whole life to have fun jumping smaller canopies, as long as you don't break or kill yourself by going too small too fast.




Mike D-23312
"It's such a shame to spend your time away like this...existing." JMH


cloud9  (D 27635)

Dec 17, 2001, 11:32 PM
Post #82 of 93 (1364 views)
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In answer to the first question, (No not at all) I think that's what this is all about inexperienced asking advice from the experienced. What could be better?



watcher  (D 24876)

Dec 18, 2001, 11:39 AM
Post #83 of 93 (1323 views)
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<took a long time to read a whole thread>

Id like to think that there really cannont be a general rule, the S&TA should be looking to see if people are exceeding thier skill level and offering good invidual advice on a case by case basis if time is available, (s)he is there to provide a safer enviroment for everyone.
That said:
1-3 Manta 280
4: Safire 269
5: Safire 219
6: Safire 209
7: Safire 209
8/9: Safire 189
4 jumps on club gear Fury 200s (yuck dont like 7 cell F111)
14 - 120: Pro 170
5 jumps on a Nitro 150
15 jumps on a Nitro 135 including a downwind landing on a night jump (they positioned the cars in the wrong direction)
20 Jumps on a Nitro 120 or Stiletto 120, ordered the Nitro

My exit weight is 180-195 its variable based on how much i eat that week at school.

Now would i recommend this progression to any of my Friends hell no. Why? cause they did not jump 10 jumps every single weekend for 5 months straight. They dont read everything on canopy flight, they havent read Brian Germains manual, which i have to say is very amazing and quite informative. They dont spend hours talking with the guys that are swooping talking about approach patterns, altitudes, progressions. And they still dont feel the canopy, they keep thinking there is this set way to flare the canopy to land it instead of flying the canopy till it stops.

My conclusion is that jump numbers dont account for much, you can have a person with 60 jumps and an hour of tunnel time easily outfly a person with 600 jumps (RW stuff, makeing a point about jump number not landing here), when i had 100 jumps i was giving landing advice to people that had 400 jumps cause they still were not landing right, cause noone bothered to tell them what they told me. Currency, current skill and how much your putting into learning something should be the primary attribute on what your landing.

But hey thats just my take on it.

Jonathan



sldiveout  (D 23892)

Dec 18, 2001, 12:27 PM
Post #84 of 93 (1311 views)
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Well,

You didn't mention how many jumps you had when you bought that 120. I also think jump numbers don't account for much but let's face it- It's a good place to start.

Many of my friends are what I would call "natural fliers" they have outstanding canopy skills and pick up on things quickly. The key is to STUDY- and be humble about your skills. No one on the planet wants to know about how good a canopy pilot you are. You learn by watching, listening and reading (of course jumping & being current).

The bottom line is this -THE GROUND DOES NOT CARE HOW MANY JUMPS YOU HAVE, OR HOW GOOD YOUR LAST SWOOP WAS. If you taunt the earth by making violent or hook turns toward it -it will maim or kill you. The earth is unforgiving, that's why we invented the swoop pond (Well, OK it's fun and it looks way cool) But ponds -especially larger ones- allow people to try things they would never try over solid, hard earth.

I like what you said about S&TA's. At Mollala (Skydive Oregon) you have be cleared through observation to land in the high-performance area, so no boneheads just show up and start hooking it into the pond.

Also, all of the studying and careful practice and currency in the world cannot prevent accidental injury due to a simple, momentary lapse in judgment or miscalculation (low turns). Making approaches smoothly will make it easier for people flare for their lives if they have to. However, even people with thousands of jumps die each year from low turns on small elipticals. Many more break legs -and not because they are hotshots or uncurrent or not qualified for their canopies, just because they made one mistake -ONE. Sucks huh?

-Dan



hookit  (D 24838)

Dec 18, 2001, 1:08 PM
Post #85 of 93 (1304 views)
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<quoting Quade>
Hmmm, let's slow down a little more.

We'll pull back the throttle a bit more and then (this is something most students don't understand) we'll have to add power to go even slower -while we maintain altitude-. Again, we'll maintain altitude by changing the angle of attack of the wing.

We're NOW going about 42 knots. We're still maintaining altitude and we're still in complete control of the aircraft. It just happens to be set up the same way it would be if we were flairing out for a landing.

Quick -- about how much lift is being created by the wing?
</quoting Quade>

Wow. Thanks for the the visual. It's a great description/explanation of why the saying 'airspeed equals lift' is not strictly true for aircraft.

In the last part of the example however, where you're having to add power to maintain altitude at the slower airspeed you're offsetting some of the plane's weight with the thrust of the prop therefore the wings are no longer generating lift equal to the force of weight (or gravity...whatever).

Let's carry that a bit further. What if I'm in an F15 and I go vertical? The wings are now generating 0 lift (if lift is defined as opposing weight) but I'm still flying.

Anyway, I guess my main point is that the analogy doesn't carry over too well from aircraft to canopies in that we don't have horizontal stabilizers or elevators on canopies therefore we don't have the same control over our angle of attack as an aircraft. We also don't have engines...(yet!).

Perhaps a better demonstration of why airspeed doesn't always equal lift on a canopy would be when a canopy pilot is in a hard dive following a front riser turn and is now hanging on double fronts and accelerating rapidly toward the ground. While airspeed is increasing dramatically, lift is not. Perhaps 'Airspeed equals Lift' should be modified to say 'Airspeed equals Lift Available'. By increasing airspeed in the dive I now have at my disposal tons more lift which will eventually (hopefully!) get used when I flatten out and get a beautifully long, smooth swoop!

Thanks for the input. It's been very thought-provoking and educational!

-Trey



TheMarshMan1  (C 40097)

Dec 18, 2001, 1:36 PM
Post #86 of 93 (1296 views)
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"What if I'm in an F15 and I go vertical?"

No offense, and feel free to correct me if you think I'm out of line, but I think thats carrying it a bit too far. The aerodynamics of a fighter jet and the aerodynamics of a cessna are two different things. Obviously, theres no way you can compare the aerodynamics of a canopy to an F-15, but you CAN somewhat compare them to the wing of a Cessna, like Paul has.

"if lift is defined as opposing weight"

yes, that is how lift is defined, however weight always acts "straight down". Meaning, no matter what the angle of the wing, the weight is not perpendicular to it, but rather perpendicular to the ground i guess you'd say. That said, if an F-15 was climbing vertically, the wings WOULD be producing lift. What the hell else would produce lift? Not the engines, they produce THRUST, remember?.

Anyways, I think this is going off on so big of a tangent that its getting rather confusing. As a pilot and ground instructor (soon to be CFI), I completely agree with what Paul has said. Lets not get too far off topic.

Just my $.02
-Marshall



freeflyguy  (D 24207)

Dec 18, 2001, 2:35 PM
Post #87 of 93 (1284 views)
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I should leave this alone. But what the hell, I am going hunting and won't be around the rest of the week anyway.

Trey, I can't promise to be right, but you are thinking the way I am in the first part of your post.

But think of these things too.
The wings of an F-15 are still generating lift when it is going straight up, It is just the lift is pulling 90 degrees from the line of flight. As always, but that wouldn't be a help in a vertical climb, so in order to keep it pointed straight up, you need something to counter it. Elevator.

Also the regular model of Drag, Lift, Thrust, and weight is stll there, but screwed up. Weight and drag are pointed straight down, Thrust is pointed straight up, and lift, ahh. Pointed somewhere, but not really needed, except to say as a component of thrust. But it turns the thing into a rocket, not really a plane.

This too, Angle of incidence is the angle the wings are conected to the fuselage of an aircraft, you can't change that unless you are flying a VTOL Osprey, but then you would just crash. Anyway. It is fixed on a cessna. It is on a parachute too, by line trim. But when you are in double fronts, in a dive, you are not allowing the parachute to fly at it's normal trim, or angle of incidence. You are forceing a change in it. That is why it keeps diving. Let it back up, and it will seek the airspeed that it is trimmed to fly at. Until it gets slowed down to that airspeed, it will give you more lift. That is why it pulls itself out of it's dive. This is true even on a high loaded canopy. It is just they may take 500 feet or more to pull out on their own. You can turn too high.

One other thing regarding engines. Have you ever seen those scary contraptions where they do connect a parachute to an engine, either a back mounted or trike? I am pretty sure they only have three or four controls. Two toggles, a throttle and wheel brake. Guess how you go up?, add power, guess how you come down? Yep. decrease power. I believe on those they also claim you can't stall them.

I just thought I would be a blowhard and beat the poor horse some more.

J.



Premier quade  (D 22635)
Moderator
Dec 18, 2001, 4:44 PM
Post #88 of 93 (1263 views)
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In reply to:
In the last part of the example however, where you're having to add power to maintain altitude at the slower airspeed you're offsetting some of the plane's weight with the thrust of the prop therefore the wings are no longer generating lift equal to the force of weight (or gravity...whatever).
Well, actually . . . (how long an explanation should I give 'me -this- time?) . . .

The major thing the prop is doing is providing power. It's usually not (and especially not in the example I used) providing any significant amount of upward thrust.

If I wanted to do the math for you (are you sure you really want to go there?) . . .

No, the reason you must add more power in the slow flight configuration is that you'd like to be able to -maintain- that attitude for more than a second or two. Otherwise, you'd slow down further and stall.

In reply to:
Let's carry that a bit further. What if I'm in an F15 and I go vertical? The wings are now generating 0 lift (if lift is defined as opposing weight) but I'm still flying.
Actually, the wings are still creating as much lift as they would at that same angle of attack, density of atmosphere and airspeed during horizontal flight.

If you point the nose of an F-15 90 degrees up, then you actually are slewing across the sky quite a bit. If you want to travel exactly straight up staying exactly over the same GPS coordinate, then you must take into account the angle of incidence of the wing and the lift it will generate.

In reply to:
Anyway, I guess my main point is that the analogy doesn't carry over too well from aircraft to canopies in that we don't have horizontal stabilizers or elevators on canopies therefore we don't have the same control over our angle of attack as an aircraft. We also don't have engines...(yet!).
Ram-air canopies have an enormous amount of control over angle of attack. Every time you pull on your rear risers you're changing your angle of attack and camber of the wing as well. Every time you pull on your front risers you're changing your angle of attack and camber of the wing as well. Every time you pull on your toggles you're changing your angle of attack and camber of the wing as well.

Engines are only useful for putting energy into the system. Other than that, they make no difference whatsoever in how a wing flys.


Paul

http://futurecam.com/skydive.html


Premier quade  (D 22635)
Moderator
Dec 18, 2001, 5:03 PM
Post #89 of 93 (1260 views)
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In reply to:
The aerodynamics of a fighter jet and the aerodynamics of a cessna are two different things.
Actually, until you get up into the supersonic range, the aerodynamics are almost exactly the same. What's different is the amount of power you can play with.

In reply to:
Obviously, theres no way you can compare the aerodynamics of a canopy to an F-15, but you CAN somewhat compare them to the wing of a Cessna, like Paul has.
A comparison to an F-15 is still valid -- especially when it comes to landings. How often have you seen an F-15 perform a split-s to land? Wouldn't that make a nifty comparison to a high performance canopy doing a hook turn? ;^) I've got video of an F-18 performing a square loop wherein he stalls it out on corner #4 and continues right into the dirt. Fortunately, the pilot lived. Damn, they make them planes sturdy.

In reply to:
"if lift is defined as opposing weight"

yes, that is how lift is defined, however . . .
Careful. Don't ever let them put words into your mouth. I think you know that's not how lift is defined, but you've opened yourself up -- don't trip.

In reply to:
(soon to be CFI)
Cool! Somebody I can talk to! Let me know when you've taken your check-ride and we'll swap horror stories! Mine's a doozy.


Paul

http://futurecam.com/skydive.html


Premier quade  (D 22635)
Moderator
Dec 18, 2001, 5:11 PM
Post #90 of 93 (1256 views)
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In reply to:
I believe on those they also claim you can't stall them.
Yep -- and ya can't spin an Ercoupe (yes, you can) and ya can't stall an airplane with a canard (yes, you can) and you can't . . . the list goes on and on.



http://futurecam.com/skydive.html


ramon  (D 26115)

Dec 18, 2001, 6:19 PM
Post #91 of 93 (1248 views)
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it is a look at me sport [In reply to] Can't Post

that is why RW and FF teams have to watch their videos so many times. the first few each team member is too concerned with what they are doing to pay attention to the team as a whole.Laugh...look at me.

ramon



watcher  (D 24876)

Dec 20, 2001, 1:19 PM
Post #92 of 93 (1151 views)
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In reply to:
You didn't mention how many jumps you had when you bought that 120.
160.

In reply to:
but let's face it- It's a good place to start.
Good place to start i agree as long as you look at all the other variables and just dont write someone off cause they dont have 500 jumps or assume that a person with 1000 jumps knows how to land a high performance canopy. I was just trying to get a more interactive (between the Canopy instructors and yourself) of judgeing current skill level and what is ok and not ok to fly.

In reply to:
However, even people with thousands of jumps die each year from low turns on small elipticals. Many more break legs -and not because they are hotshots or uncurrent or not qualified for their canopies, just because they made one mistake -ONE. Sucks huh?
I agree it does suck alot, and i think if your going to do this you need to be acutely aware of the risk you are taking for enjoyment. And as you said the ground knows no difference in a 1 jump AFF student and a 5000 jump swoop specialist it hurts either way if you screw up. Always understand the true power of that small piece of coated cloth above your head can do to you if you dont stay focused and make good desiscions and know when to not make that last hook turn when you might be alittle low.

Jonathan



alan  (D 17868)

Dec 20, 2001, 4:03 PM
Post #93 of 93 (1137 views)
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I'm gonna jump in here kinda late, but with all of the discussion on wing loading, I haven't seen any mention of density altitude. I hope this doesn't make this too technical but I think it is important to note that a 1.2 wing loading on a 72 degree day at 750' msl with 30% relative humidity will be considerably different than on a 92 degree day at 1500' msl with an 80% relative humidity. Jump in the Denver area and that fairly conservative 1.2 becomes a pretty aggressive wing loading.

alan


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