Sinking a Canopy for Landing

[jfields 0]

This goes back to Skreamer's comments in the San Diego incident thread.

There are select times when it seems like sinking a canopy straight down would be a desirable course of action, similar to the ability to land on rear risers alone. Neither is the preferred method, which is a nice safe approach in low traffic, followed by a standard flared landing. But when things aren't going well, due to ground obstacles, traffic, or whatnot, what are your thoughts on sinking a canopy in? (Obviously, I'm not dealing with the chain of events bringing you to a low situation, but only once you are there.)

I know that much of this is canopy-dependant. Some are ill-suited to this, due to planform and an individual's wingloading, etc. Mine seems like a good candidate. I fly an original Sabre 190, loaded at about 1.15:1. Playing up high, I've pulled toggles down to full arm extension and held numerous times. I've observed the huge loss of airspeed, the canopy's mushiness and lack of responsiveness. But I also know that doing that on my particular canopy (with my particular arm length) will not cause the canopy to stall and collapse. Whether my lines need adjustment is a different issue, but I know that full extension is within the safe realm of what my canopy can handle while remaining straight and stable.

In a very full brake position, my horizontal airspeed is minimal. Knowing ahead of time that this would be a PLF landing, would you advise trying this under a controlled situation, so that you can have it in your proverbial bag of tricks, should the need arise? (I've talked about a similar pre-planned rear riser landing with BillVon, which I hope to be trying under supervision at Eloy.)

[billvon 2,991]

I couldn't do it safely on mine sinking it in the whole way, but I could do a long sink followed by what I call a "jennifer" landing (named after Jennifer Powers, the first person I saw do this.) For that sort of landing you hover in half brakes until you're at 100 feet or so, then let them up, let the canopy dive, and flare normally at the end. It can get you in to very small areas since the canopy tends to dive as it recovers, but you still need the room to flare and run it out.

[jfields 0]

Bill,

I understand that it wouldn't work on small, highly-loaded canopies, but what do you think about it in the situation I described? Namely, a fairly light loading and a big, docile canopy? Just as in the rear riser landings, as something to know and have tried, but then put it aside, hoping it won't be needed. (And also knowing that it will have to be revisited in the event of any canopy change.)

[billvon 2,991]

>I understand that it wouldn't work on small, highly-loaded canopies,
>but what do you think about it in the situation I described?

No problem at all; I think you've just described an accuracy approach. As long as you stay out of really deep brakes, you should be able to sink into a fairly tight spot - and still have a little flare left at the end. Note that this doesn't work well in light winds since your glide doesn't deteriorate a lot until you're in pretty deep brakes, so this would be more applicable for windier days.

[bsoder 0]

Quote

...hover in half brakes until you're at 100 feet or so, then let them up, let the canopy dive, and flare normally at the end.

My wife and I are both working towards our A licenses right now. One of the requirements is a braked approach and landing. It was described to us as "half brakes to 40 feet altitude, let up, then flare out normally." Sounds basically the same.

[AggieDave 6]

I use the braked approach you described sometimes if I'm going to overshoot the video guy/catchers when doing tandems. Very helpful thing to have in your "arsenal."

As for sinking in a loaded canopy, well, I've done it with the Heatwave I used to have, although the last time I had to do it (off field landing), the canopy finally stalled about 3ft above the ground. No biggy, nothing a good PLF couldn't handle. I had sunk down for about 35-40ft on a Heatwave loaded at 1.7:1.

Although, it would have been MUCH easier to do with a Navigator 300 or similar large canopy.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[Kdsosso 0]

Will "sinking in" increase the dive speed?
Thanks

[bodypilot1 0]

NO. Not unless you pull your toggles down far enough to stall your canopy. Half brakes will reduce your forward speed.
Hover in half brakes until you're at 100 feet or so, then let them up, let the canopy dive, and flare normally at the end.

www.WestCoastWingsuits.com
www.PrecisionSkydiving.com

[billvon 2,991]

>Will "sinking in" increase the dive speed?

No, but if you let up on the brakes, the canopy will dive (rapidly) to recover its lost speed. So be careful how you handle that; either hold some brake all the way down or be sure you have enough altitude to recover if you want to let up the brakes to get some speed for a flare.

[skycop 0]

An effective way to sink a canopy is to "ride the wire". Imagine a wire coming up from your target at a 45' angle. This is done at about half brakes, if you're high and going to overshoot, more brakes, if your short and want more glide, less brakes. This can be done mainly with just wrist and a little forearm.
The main canopy of choice for this is usally a large 220-290 F-111 or a large ZP 210-230 7 cell. I use a 290 StartracII. It doesn't work too well with my Tri 190, but did work (somewhat) ok when I had a Tri 220.
The whole point being, you should be able to squeeze the last lift out of the canopy by flaring the rest of the way (without going to full flight) just before landing. You normally land coming straight down at the target. This allows for a very steep approach into a tight landing area.
The drawback being if you sink too hard in brakes or too soon, the canopy can stall and ouch.
It takes alot of practice, but it is very effective

"Just 'cause I'm simple, don't mean I'm stewpid!"

[rigging65 0]

Quote

The whole point being, you should be able to squeeze the last lift out of the canopy by flaring the rest of the way (without going to full flight) just before landing. You normally land coming straight down at the target. This allows for a very steep approach into a tight landing area.

It should be noted that this "squeezing the last lift out..." only works with big, lighter loaded canopies. Trying this with your 170 loaded at 1.4 is going to result in a nice, hard PLF...or a tweaked ankle. Canopies need airspeed to create lift. Sinking it in eats up a lot of this speed...which makes it tough to get lift.

"...and once you had tasted flight, you will walk the earth with your eyes turned skyward.
For there you have been, and there you long to return..."

[skycop 0]

My point exactly,
Most military demo teams I've had contact with all jump big f-111 7 cells. I wouldn't sink a smaller canopy unless it was an emergency off-landing type situation. As I stated in my previous post, I sink a 290 Startrac II, not my Triathlon 190.

"Just 'cause I'm simple, don't mean I'm stewpid!"

[ryoder 1,590]

What you need to pull this off is an accuracy canopy.
There are two important characteristics needed:

1. Aspect ratio of about 1.9:1 This makes the canopy
very stable in deep brakes. Canopies with higher
aspect ratios will be very twitchy, requiring
constant steering line input to hold a heading.
Also, higher aspect ratio canopies will have a
nasty tendency to fold their tails in half like a
fortune cookie.

(Aspect ratio = span^2 / area. For rectangular
canopies, this reduces to: span/chord.)

2. Wing loading of 0.7:1 or less. Once you get into
full deep brakes and stop forward speed, you no
longer have a wing over your head, but instead have
a rectangular drag chute. At this point it is no
longer flying, and the vertical descent rate will
accelerate, so bigger is better.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[Luv2Fall 0]

I knew there was a reason I like my PD280....mini tandem chute all the way lol.

[AFFI 0]

Braked approach and Landing requirement: an interpretation, for that's all that it is, would lead me to conclude that the degree of control input by the student would absolutely be equipment/wing loading dependent, as well factoring in the wind conditions existing (down to the deck) when the canopy flight in question is planned.
The definition of what is "braked" will vary a bit from DZ to DZ and Instructor to Instructor. After all, isn't every landing aside from full flight a 'braked landing" at some point prior to, or perhaps after, ground impact??? Good, bad or indifferent.
I'm sure that the spirit and intent of this requirement is to ensure that the student understands and can discern between the various modes of flight of their canopy, which on their final student canopy flights should include approaches to and execution of a stall and demonstrating the ability to recover to full flight at an extravagant altitude, ergo, way up there, probably immediately following the determination of a good canopy, subsequent to the controllability check. This is directly paralleled in aviation flight instruction.
How many folks have been killed over the years due partly or wholly to an imperfect understanding and feel for the safe envelope of flight for the canopy that they were using when they frapped? So a clear understanding of how to avoid a stall when the chips are down (new DZ, last load, running late, bad spot, tiny field, perhaps unfamiliar equipment, etc., or even a reserve ride) is essential. How many skydivers (including Instructors) out there these days have never truly stalled their canopy?????? "Oh, that's too scary." And their point is? The alternative is even scarier for most normal folks.
In all cases common sense should be exercised by each Instructor, therefore in essence tailoring the requirement to each student, not simply blindly adhering to a requirement in the program, applying what I would term 'collision avoidance of a cookie-cutter approach to canopy flight instruction'.
The spirit and intent of the accuracy requirement is to have the student demonstrate proper expertise in landing their parachute where they plan to, without guidance. This is not a contest for Instructors in directing radio-controlled student skydivers to a spot landing. One consideration is that the "A" License requirement went up to 25 jumps in September 2003 - that's five more opportunities to work with "problem children" on their canopy skills.
Experienced jumpers out there who did not have the luxury of going through an instructional program with emphasis placed on canopy piloting skills, it might be a prudent choice to participate in your survival by further education. Become proficient in slow flight and flat turns, braked approaches, rear riser control (steering and flaring, what if you loose a control line at 200 feet?), and learn how to use your front risers and how your canopy flight is affected by a plethora of control inputs. Run every conceivable scenario through your preparations and practices and be prepared fur the unexpected. Remember, if it can go wrong it will eventually. We are jumping out of airplanes! Train yourselves, be safety conscious and have the greatest fun humans have ever had!

Mykel AFF-I10
Skydiving Priorities: 1) Open Canopy. 2) Land Safely. 3) Don’t hurt anyone. 4) Repeat…