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Welcome to the Pilot-Attached Drogue (PAD) Web site. Here you'll find information about both commercial and home made versions of pilot attached drogue chutes for hang gliders. You can buy a commercial drogue chute, or you can make one like mine, the PAD, using the plans and guidelines provided here. ...Mike Sandlin |
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At right, the Metamorfosi Deltastop Drag Chute (old version, similar to the current Aeros setup), a commercially available system.
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To Buy a Drogue Chute:
Wills Wing , http://www.willswing.com/Accessories/drogue.asp http://www.willswing.com/Accessories/drogue.asp offers the Drogue 'Chute, a pilot attached system made by Free Flight Enterprises, a well known manufacturer of hang glider reserve parachutes (LARA, PDA, etc.). It's similar to a PAD but with a swivel and a pull-down apex. Overall it looks good to me, it's the right size canopy in the right place. See their description and guidelines under "Products/ Harnesses and Accessories" on their Web page. $100 with container, plus $60 for optional shop installation.
U.S. Aeros, justfly.com., also carries a pilot-attached drogue, the DragShoot, which looks a lot like the old version of the Delta Stop (see photo above). I havn't flown with it but I've examined it and seen it used, and it appears to be a well made, high drag system, good for emergency use. Like Deltastop, they talk about deployment low on final, but pattern altitude deployment is still an option. $79 with sew-on deployment bag.
Icaro provides the Metamorfosi Deltastop Drag Chute which is effective and well made. This chute creates as much drag as you can handle and would be a good choice for emergency use. An excellent sew-on pocket deployment system comes with it. This is the quick and easy deployment system where you just pull a small handle to turn a pocket cleanly inside out, dumping the drogue out into the slipstream. At the Icaro2000 Website see http://www.icaro2000.com/p1530.htm for Deltastop details and procedures. $115 with deployment pocket.
To Make a Drogue Chute:
You can make a custom drogue chute, the PAD, from the plans provided here. The guidelines and plans that follow apply to this home made system. This system is effective, practical, and really cool.
GUIDELINES FOR THE PILOT-ATTACHED DROGUE (PAD) CHUTE
Mike Sandlin...............May 26, 1998
INTRODUCTION
The pilot-attached drogue chute is intended to make hang glider landings easier, safer, and more accurate. When deployed, the drogue chute reduces hang glider performance by adding parasite drag, allowing steep, straight approaches with reduced groudspeeds and short groundskim distances. In general, landing pattern airspeeds are unchanged (or faster) with a drogue, while glide angles are steeper and energy retention is poor. The added drag does not necessarily make the glider fly slower (the pilot still controls the airspeed in the usual way: by sound and effect, not by bar position), nor does it much influence stall effects or handling. Ground speeds are noticeably reduced because of steeper glide angles, not reduced airspeeds.
When attached to the pilot's harness so as to pull approximately through the aircraft center of gravity, the pilot-attached drogue chute has no great effect on glider handling. No special flying skills are required for drogue landings beyond allowing for reduced glide and penetration. Unlike the keel-stabilized drogue, this canopy is unstabilized and will bump around in flight, which can be annoying, but the effect is minor and well within the scope of the landing conditions that we all have to deal with in hang gliding. The benefits of drogue use more than compensate for the inconveniences, especially in demanding situations involving high performance gliders.
DESIGN AND PHILOSOPHY
The PAD chute is a small, simple drogue chute designed to be reliable and effective when deployed from a hang glider pilot's harness. This system differs from the Deltastop in being slightly smaller, simpler (no split lines, no apex pull-down, octagonal planform), and shorter.
My current design, PAD98B, can be characterized as follows:
•Flat octagonal canopy, 60 inches edge to edge, 8 lines (35 inches @), 6 inch diam. apex hole
•Attachment to the base of main harness webbing, via short bridle, left side mount preferred
•Fastex Clip (one inch) at attachment point provides emergency release
•Chute is stowed in pocket on harness
•Re-pack is a randomized wadding, canopy folded around lines, taking about 30 seconds.
The pilot-attached drogue chute is intended to be a convenience, not an emergency device, since it cannot be relied upon to deploy with complete reliability or promptness in critical situations.
SUGGESTED FLIGHT PROCEDURES
The chute is deployed by removing it from its pocket and dropping it. This can be part of the landing sequence, done just after unzipping the harness at 300 to 500 feet above the ground. Typically I deploy my drogue about half way through the downwind leg of the landing pattern. There are no special opening effects except a firm force on the harness, which will require the nose to be lowered to the new glide angle in order to retain pattern airspeed. The landing pattern should be flown at normal (or faster) airspeeds but at greater than normal altitude in anticipation of poor glide angle and lack of penetration. Good results have been achieved (in moderate winds) by flying final approaches at a glide angle of two or three to one, aiming for the ground several wingspans short of the intended stopping point. As always, extra altitude must be retained to allow for sink on final approach, so some maneuvering for last minute altitude loss will often be required. Be aware that glide angle will now get worse at higher speeds, not better (i.e., don't expect to go farther by diving). The last glide down to groundskim level should be made fast enough to assure that adequate airspeed is retained for a proper flare, which should be performed as required in a conventional manner.
If you find yourself looking short on final approach with the drogue chute out, either accept the shortfall or release the chute and land without it. Try to make this decision early, but if the chute must be released at low altitude do it smoothly and without being distracted from critical control of the glider on final approach. The chute (my system, the PAD) is released by reaching back and squeezing the Fastex clip, which may be difficult if wearing gloves.
In general, don't try to deploy a drogue chute at low altitude, because if it fails to open, you may not have time to fix or release it, and it might suddenly come open at the worst possible time. So far I have not heard of any instance of a conventional pilot-attached drogue completely failing to open , but if necessary a quick jerk on the bridle might help to open a reluctant canopy.
The most typical landing error when first using a drogue chute is to make too low a turn onto final approach, so all the altitude is used just aligning, unbanking, and diving through the wind gradient with no airspeed left for the flare (whack!). To avoid this, try to come in straight, fast, and level on at least the last hundred vertical feet of final approach, especially when using the drogue the first time.
FABRICATION, INSTALLATION AND PACKUP
Proceed according to the PAD98A drawings (-1 through -3). A good canopy can be made by modifying the 6 foot nylon beach umbrella available in many markets to the PAD dimensions. High strength and careful construction are not required for drogues chutes: they are useful appliances, but not critical flight items.The shroud lines are fabricated into two groups so that during packup the pilot can easily check for crossed lines by separating the two groups (two groups of different colored lines is the best arrangement). The only flight failure I have experienced with the conventional PAD was a brief deflation due to twisted lines, preumably due to a careless repack.
The drogue can be attached to the harness anywhere in the center back of the harness, but the easiest setup is to attach one end of chute bridle (the Fastex Clip) to the lower end of the main harness suspension webbing where it meets the main body of the harness, or thereabouts. Be careful not to tie over the main emergency parachute bridle if it runs through this vicinity. If you have a harness with two suspension webbings coming down to the body of the harness, choose the side away from the main emergency parachute bridle. This will usually mean attaching the drogue on the left side of the harness. Side attachments work very well.
A normal re-pack is not a high precision operation, it's more like "wad it up and stuff it in", but there are some points that should be mentioned. Prior to packup separate the two line groups to check that the lines are in order (no cross-overs). Pack up the chute by laying the canopy down on its side with the lines placed on the fabric. Fold the canopy randomly over the lines to produce a solid wad with no lines exposed, just the bridle coming out from the fabric. (The eight shroud lines should not be exposed because they can snag on zippers, wristwatches, etc.). Stow the wadded chute in a pocket close to the point of attachment. I use a zippered hip pocket that came on my harness, but pockets can be sewn on (the Deltastop setup is the best of all, a sew-on pocket/quick deployment system). One pilot just stuffs his chute into the open glove slot under the pocket on his chest. The bridle need only be long enough to reach from the pocket to the attachment point, since it is used only to avoid having shroud lines exposed on the outside of the harness (the shorter the bridle, the better for drogue effectiveness and stability). Some pilots use the Fastex release buckle to detach the chute for repack, but this is not necessary.
NOTES AND OPINIONS
Drogue chutes can be used for every landing (this is how I use mine). Frequent use is the key to reliability and skillful application. It's unfortunate that many pilots believe that "normal" landing skills must be maintained by limiting use of the drogue chute to difficult situations. The pilot-attached drogues are highly reliable, so we should advantage of them and use them like landing flaps, to make every landing safer and easier. The landing procedure you want is the one that minimizes your long term chances of damage or injury, and this means using a drogue chute for every landing.
The drogue chute is no panacea for poor landing skills or other flying problems (plenty of aluminum has been broken using drogue chutes), but it helps.
I have landed in high winds with my drogue chute, perhaps as strong as 30 mph., without undue difficulty. The benefit of a drogue in high winds is the rapid vertical descent, getting down fast instead of hovering over the landing area. In rough winds you can choose your landing time by waiting over the LZ for turbulence to pass, then puting out the drogue and diving down to the ground before the next turbulent cell arrives.
Drogues are very (very) helpful in downslope landings.
There has been speculation about using a drogue chute for vertical escape, which involves maximizing descent rate to escape dangerous lift , gust fronts, or clouds. This application has not been tested. Mark Stuckey advises that the nose down trim effort required to hold high speeds for prolonged descent may be prohibitive, i.e., you'll wear your arms out holding the nose down before you can dive out the bottom of a big cloud. I suspect he's right for gliders with strong trim forces.
Contrary to what might be expected, my tests have shown that the farther forward the pilot-attached canopy can be placed, the better it will work, especially in groundskim and flare.
I begin check flights on the training hill with the chute out on the ground. The launch feels almost normal as long as I use good technique (i.e., I run hard). The chute inflates during the launch and operates normally for the landing.
For safety, during normal deployment, do not bring the chute forward or upward. Don't drop it in front of the base tube or up over either of the rear cables. Be aware of potential snag problems, and avoid extended handling of the chute in flight (just pull it out and drop it).
WHEN POSSIBLE:
1. Put the chute out high and early, then fly a high pattern to a fast, straight final approach.
2. Avoid deploying the chute when low on final approach, because you need both hands to control the glider and there's no time to fix problems or change plans at this point.
3. Keep the chute dry and use it frequently for reliability and familiarity.
4. If you are going to use the emergency release, try to do it high and early. "When in doubt, release and land without".
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The latest and greatest as of October 28, 1999
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