Wednesday, July 11, 2012

reserve parachutes for PPG

NB.  This is a Work in Progress:  I'm still waiting for some dealers/mfgrs to get back to me with weights/prices on PPG containers and bridles.

Researching reserves, I learned two things that came as a surprise:

Firstly, that it is vitally important to know your actual all-up weight to measured against the reserve’s rating, in order to get a safe descent rate and to minimize injuries on landing.

A recent study from the DHV (The German federation for Hanggliding and Paragliding) found that injuries significantly increase as you start to get near a decent rate of 6.8m/s.  This is the minimal standard for reserves in Germany, but they themselves now recommend that if your chute is rated for 6.8 m/s that you stay 25% under the placarded weight so that you slow down a bit further.

(*The link below is not working and the original article has not been updated, but a summary follows below:)

The DHV examined all the reported incidents where emergency parachutes had been used by DHV pilots in 2003, and discovered a clear trend: in eleven incidents, (those in which the pilot's fall had not been arrested by trees) serious pilot injury occurred in all events where the load was close to the reserve's certified maximum payload.  Not exceeding the max - just simply close to, but within the max - within 78% in fact.

It seems clear that 6.8m/s descent rate is too fast, but while the DHV have no plans to change their current certification minimum, they are unofficially recommending that pilots use slower or larger chutes.  The German 6.8m/s descent rate is fast; considerably in excess of the BHPA 5.5m/s recommendation, which follows the CEN (European Committee for Standardization) rating for reserves that most North American pilots are familiar with.  But this lower rate of descent is dependent on staying within placarded weight.  It is therefore, extremely important to pay attention to your actual take-off weight to ensure your decent rate isn't too fast. 

The second surprising revelation was finding out that my all-up weight was more than I initially believed.  By a lot.  And that is probably true for most of us.  I was hoping I might be able to get away with a Medium size in some of the lightweight chutes I was looking at, but I was only dreaming. And while I'm a Medium in most things, even the size Large in many of the options was going to be too small for my all up weight.

Someone like myself, with a stable, soaking-wet, morning weight on the bathroom scales of 175 pounds (80 kg); such a person may find that their base weight can fluctuate by another five-pounds, up or down, over the course of the day, but generally with a higher reading later in the day.  

Then our hypothetical pilot must need to weigh him/herself again wearing clothes.  My pants, T-shirt and running shoes, add about four pounds, and I can factor in another pound when I include my 4.8 ounce iPhone, and my wallet, watch and key chain. 

My coldweather flying weight is a full 10-lbs above my summertime weight with the addition of boots, and extra clothing in the form of microfiber under-layers, a fleece sweater, balaclava, heated gloves and  a flight suit.

Gasoline weighs about 6 lbs 4.8 oz per gallon, (6.3 lbs) or 750gr per liter.

Add 2.3oz of weight for 2.5 fluid ounces of 2-stroke oil for a 50-1 mix per US gallon. (Or 17gr for 20mL to do one liter.)  Seriously, all the sundry miscellany you loft adds up, and weighs more than you probably think.

Also, what some pilots don't realize, is that they must include the wing in the overall weight, as the deployed reserve will now be carrying the additional weight of your collapsed glider.  This might add another ten to fifteen pounds.  It may be reduced a bit by its own drag and loft, but it's still adding some poundage to your all up weight. 

Now add in the motor weight.  The actual motor weight.  Because it's important to bear in mind that there is a lot of obfuscation and exaggeration going on in regards to advertised paramoter stats.  Some sellers quote the motor only without harness and/or prop, and some of them outright lie.  So your motor may in fact weigh more than you have been led to believe.  I suggest taking the bathroom scale out to the field with you the next time you suit up, and actually check the numbers when you're all gassed up and ready to go, and then again, while holding the bunched up wing in your arms if you don't know the wing weight already.  

So an "average" 80kg person like myself could be well into the 130kg (287 lb) range when I add everything up, especially once I include in a helmet, googles, gloves, camera, mirror, radio gear, altimeter, vario, and all the various and sundry other crap we love to drag up with us.

With this in mind, if someone is very close, or even a little bit over, a particular reserve's maximum weight, they might want to consider the next size up, or a different model.  Otherwise, you won't be coming in at the hoped for 5.5m/s, but some unknown amount faster, maybe approaching the 6.8m/s figure and almost certainly in for some degree of injury.

I made notes on a few popular reserves, and to get the lightest reserve I could find that would still do the job, and not be onerously heavy.  Some manufacturers tell you the all-up weight of the system up front, (reserve, outer-container, and bridle) and some don't.  Other brands appear less competitive when you notice that the advertised price is for the smallest size only and completely unsuited for PPG.  So hopefully this list I compiled will help make your decision easier.

Gin Yeti Light (#40)
Weight: 1.75kg + 140gr + 40gr
Descent Rate: 5.13m/s
Weight Range: Up to 120 kg 

Price:  $850 (Bozeman) $800 Fly-Above-All
Container: $70 (140gr)
Bridle: $75 (40gr)
Total: $945 Total actual weight: 1.93kg

Beamer 2 Steerable Reserve (Standard size) 
Light – Fast opening, super slow decent, and steerable.
Weight: 1.9kg + (Front container from High Adventure) 239gr  (Integrated split risers with attached brakes.)
Descent Rate: 3.8m/s
Weight Range: Up to 130 kg 

Price: $995 (Bozeman) $162
Total: $1,157 Total actual weight: 2.169kg (with container)
If this chute has any downside, it might be in finding an experienced Rogallo style repacker. But the manufacturer says it isn't difficult, and more reserve techs are coming on line.  One pilot suggested that a steerable reserve is probably unnecessary, because as upon deployment, you will probably be too busy pulling your wing in and holding it, so that you will not be able to do much steering anyway.  But if you have air to spare, or an immediate need to turn, you can steer this baby, and come in soft.  There are videos where you can watch pilots actually walking out their landings.  This reserve is amazingly light, with a truly remarkable descent rate, and is very high load carrying.  And did I mention very fast opening? Twice as fast as some canopy style reserves.
High Adventure says they are working on a new Beamer, dedicated for PPG with a larger surface area (160Kg load), and slightly different risers.  No ETA, but many of us can work with the Beamer 2 at 130Kg.

Sup'Air Xtralite (Large)
The large is rated for only 115 K which puts it in the lighter carrying range for PPG. 
Made from super-light Porcher Skytex 27 material.
Weight: 1.35kg +100gr (Includes bridle)
Descent Rate: Less than 5.5m/s
Weight Range: Up to 115 kg 

Price:  $964 (USwingnuts)

Small is $809 plus $155 markup for Large = Total $964
Container: $87 (100gr)
Bridle:(NA - Included)
Total: $1,051 Total actual weight: 1.45kg 

Miniplane Snip L (also called Way Richly) (30m Large)
Fast opening time of 4 seconds/
The L has a max weight of 130.  System weight of 1850 Gr and a bag weight of 290 gr
Two containers are available, the top mount (below) and a squarish "cross country" version with internal storage.
Weight: 1.850kg + 290gr container + (Bridle is  included)
Descent Rate: 5.5m/s
Weight Range: Up to 130 kg 

Price:  $825 (Trikebuggy) All-up package on ebay for $825

Container: $75 (290gr)
Bridle: (NA - Included)
Total: $825 Total actual weight:  2.30kg

APCO Mayday 18 Flat Packed for PPG 
Tried and tested design.  The 18 will suit up to 120kg. For heavier weighted pilots the Mayday 20 might be the way to go, with a carrying capacity of a whopping 160kg and a weight of chute only 2.69kg
Weight: 2.20kg +?gr + ?gr
Descent Rate: 5.4m/s
Weight Range: Up to 120kg 

Price:  $663 (Litetouch Films)
$773 for the Mayday 20
Container: $85 (?gr)  LTF

Bridle: $40 (?gr) LT
Total: $785 Total actual weight:  2.20 +? +?


Weight: 2.080kg +?gr + ?gr
Descent Rate: 4.48m/s (excellent)
Price: $1,150
Weight Range: Up to 130kg
Container:  $46 (?gr)
Bridle: $30 (?gr) Apco suggests using your own bridle suitable for your PPG
Total:  Total Price: $1,226  Total actual weight:2.08 +? +?

KARPOFLY RS 130 (Nirvana)
Weight: 1.75kg  +?gr + ?gr
Descent Rate: 5.5m/s
Price: $500
Weight Range: Up to 130kg
Container:  $54 (?gr)  (Has a loop velcro top for instrument attachment.)
Bridle: $30 (?gr) 
Total Price: $584 Total actual weight: 2.32kg (including Nirvana case and split bridle) 
This one isn't getting much attention, but it is looking good on paper.  it is EN 12491 certified, made of Porcher 9081, area of 33 meters, 16 panels, with a 2.5 second opening time,   
This Czech parachute seems to be a new item in Paradrenalin's inventory, and may not featured on the website, but is stocked and available now on request.

Lots of more detailed info on reserves here:

And here, from Crosscountry Magazine, including some European models not commonly seen in the USA.

And this 2013, Biglist post from Dave at BlueSkyPPG in California is interesting:
He believes that due to differences in design, PPG reserves, (unlike military parachute reserves), do not do well after a deployment.  He says, "Anyone who has done a repack on a thrown (PPG) reserve can tell you it never repacks right. Each gore is slightly stretched and different than the one next to it, the lines are no longer equal lengths, plus the bridle usually has a nylon sheath hiding any possible damage to the tubular nylon core. A 1" nylon bridle single nylon bridle is more than capable of holding your weight for a single deployment. but multiple deployments are asking for trouble. That's why skydiving risers are 2" nylon rated around 6,000 pounds and there are four risers going to the reserve not one like on ours."

This is provocative stuff, but he also makes the point that most PPG pilots, "Think nothing of spending 8K for equipment, $3K on a new paraglider every 3 or 4 years but not $600 on a reserve parachute that will not only save their LIFE but also will last 25 years with regular inspections. Better to have a reserve and not need it than need it and not have it."

High Adventure, maker of the Beamer 2 has the following to say, however, in their FAQs:

Q - Can I use the Beamer 2 in a SIV training over water?
A - Yes. We deliberately abandoned ultra light, cheap material. Fabric and lines are high quality, durable and well-proven in parachute sports.

A direct question whether the Beamer can be repacked and redeployed was not answered, but from the above FAQ, it appears so.

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