The following are lecture notes taken by Craig Shelton during the
January, 1997 parachute clinic presented by Betty Pfeiffer of
High Energy Sports. Betty has reviewed these notes and has said that
they may be distributed freely, provided that she and High Energy Sports
are properly acknowledged. I've done some HTML formatting and corrected
a handful of typos, but otherwise these notes are exactly as sent by Craig
to the listserv on January 29, 1997.
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Parachute Clinic Lecture Notes
Clinic presented by Betty Pfeiffer, President, High Energy Sports
1081 Shepard St., Unit 'A'
Anaheim, CA 92806
Phone: 714-632-3323
FAX: 714-632-6622
Email: Betty@highenergysports.com
Clinic sponsored by the Capital Hang Gliding Association
(CHGPA)
and the Maryland Hang Gliding Association
(MHGA)
Held January 18 & 19, 1997, in Leesburg VA
What follows are the notes I took during the classroom portion of this
parachute clinic on January 18. Any errors or omissions in these notes are
my fault. I encourage any pilots interested to obtain copies of the
several articles and reports which Betty gave to all registered attendees.
Those papers explain more fully a number of the points found here.
On January 19, the clinic consisted of practical exercises, deploying
parachutes while hanging in simulators. We all had a chance to throw the
parachutes with left and right hands, and while experiencing spins, and
classmate-induced turbulence. Pilots then had their parachutes inspected
and repacked, with repack instruction. If you missed the session and have
an opportunity in the future to take part in a clinic like this one: DO IT!
The information and practical experience are invaluable to all pilots.
Betty Pfeiffer has authorized the free distribution of these notes...
please pass them on to your pilot friends.
Parachute Clinic - Lecture Notes
The System Components:
The parachute system includes all items that take part in getting
you to the ground under canopy: parachute, bridle, swivel, carabiner, hang
loop, harness, and hang glider.
Importance of remembering this: what is the weak link of the
system? Inspect and maintain all parts to ensure a reliable parachute
system.
The canopy inflation process needs time for the 'chute to reach
extension, air to run up the air channel, and finally snap open from the
top to the bottom. This means you need ALTITUDE. Keep your altitude in mind
at all times.
When throwing the 'chute, throw into CLEAR AIR and UP.
Considerations When Deciding To Deploy
- Pilot Awareness
Know your ALTITUDE - do not let other factors distract you
from deploying while at sufficient altitude for the canopy to inflate.
The deployment of the parachute assembly is not instantaneous...
there is a sequence of events as the parts extract from the bag and extend
to their full length:
- BRIDLE plays out,
- LINES pull out and extend.
- CANOPY extends, and begins to fill with air through the air channel
- The ENTIRE SYSTEM STRETCHES OUT as the air pressure builds, until
the 'chute inflates from the top down.
This sequence takes TIME, and in this environment, you measure TIME as
ALTITUDE!
Old style flat circular and conical design parachutes need 150 to 200 feet
to inflate. Newer pulled down apex (PDA) 'chutes need 100' to inflate.
Recent advance design 'chutes may need just 50'.
- Awareness of Body
Tumbling by the glider can be violent. Spins can induce
blackout AND BROKEN BONES. Have parachute options in mind before the flight
- you may not have much time to decide once an emergency occurs in
the air!
- Control Frame
If the control frame is still intact, there is a natural tendency
to keep hold of it. This gives you a feeling of security. However, this
forces you to extract and throw the 'chute with only one hand. Be ready to
throw with two hands if possible - you can get MUCH more force in the throw
that way.
- Forces at Play
Early HG accidents involved glider damage which caused lots of tumbling.
This would often wrap the 'chute bridle up in the glider.
With changes in glider design, beginning about 1985 reported accidents
started involving one leading edge broken, while the other side remained
flyable. This resulted in increasing number of broken tumbling gliders
becoming broken spinning gliders.
You still want to deploy the canopy as quickly as possible in these
circumstances because:
- the centrifugal force of the spin may make it very difficult to deploy;
- the spin may induce blackout; and
- the violence of the spin may break the other leading edge,
resulting in a tumbling glider.
Often at this point the pilot gets thrown about violently into the glider
frame, further breaking the glider AND injuring the pilot.
In the turbulence of a spinning or tumbling glider, LOOK AT THE HANDLE and
focus on it. This act may help avoid getting too dizzy to deploy.
- Know Your Options
Think of how you will throw the 'chute with either hand, or with both hands.
If you have a ballistic 'chute, know about your hand-deploy options (if
you have them).
Think about situations or conditions when you might decide to wait or not
deploy.
Consider the weather situation, possible landing areas, power
lines, etc.
- Power Lines
If you get hung up in power lines, DO NOT TRY TO CLIMB DOWN.
DO NOT ALLOW UNTRAINED RESCUERS TO APPROACH OR TOUCH YOU.
Until the power is turned off, a grounding connection can kill the
suspended pilot and the rescuer. Insist on staying in the lines until
community emergency response and power company officials confirm that the
lines are no longer live.
- CRITICAL ALTITUDE - Know your minimums and limits
Know your personal ability to throw - what can you do, with which arm?
Direction of throw - go for up as much as possible - into clear air.
Tumbling may give you a choice of direction.
- Glider failure mode
Newer gliders may have one leading edge fail; go into a spin; then lose the
other side, and change into a tumble.
- In a SPIN
Throw in the direction of the spin. This gives you more energy
in the throw AND makes it less likely that the bridle will wrap up in the
glider.
What-If Discussions
- You tumble four times then the glider rights itself...
- You do not know what structural damage the tumble caused. There may
be some cases it is better to land than deploy your 'chute. You have to
evaluate the situation: altitude, weather, proximity to landing zone, etc.
- After a mid-air collision, you see badly frayed side wire...
- Evaluate the situation. Consider getting altitude or better
position relative to the landing zone. Prepare to deploy. You may want to
fly with one hand on the 'chute handle, ready to deploy if there is a
failure.
- You are coming down over water...
- Get your hook knife ready, and decide where to cut: hangstrap?
harness shoulder? pad? Plan your escape from the rig. Do you want to secure
into the frame before impact? Once in the water, get away as fast as
possible - get out and dive down and away from the rig, swimming upwind if
possible.
- Glider breaks at 50' over treetops...
- THROW the 'chute. Keep throwing it if needed until impact. Even if
it does not deploy, it may tangle in the trees and slow your descent.
- You are flying in a crowd and hear a loud twang from the upper rigging...
- The glider is still flyable. Upper rigging is there to deal with
negative loads. However, if you are in strong thermal conditions, you may
decide to deploy.
- You are in a tree, 30' up...
- Use your gear to secure yourself. You may simply tie yourself to
the tree and wait for help. You may be able to use the 'chute and lines to
climb down. Advice from a pilot who did this... descending the lines, his
hands slipped faster and faster as he moved from canopy to lines to bridle.
His hindsight advice - tie knots in the run all along the length
to give grips for climbing down.
- You've had an accidental deployment and the glider is intact...
- Try to fly it first. You may well be able to perform a normal
landing. Be aware of bridal placement and controllability. If the 'chute is
acting as a drogue to the glider, you should be able to fly down, BUT,
watch out for being pulled into a full nose - down attitude.
- You're flying and see another pilot deploy a parachute...
- Do NOT fly around the area, leave the airspace and land as quickly
as possible, possibly radioing for help, or announcing the pilot's
position. If Air Rescue is called, they will not fly into airspace occupied
by hang gliders! Your presence in the air could prevent Air Rescue from
assisting.
Know whether your 'chute can withstand a free-fall deployment; many will not!
Videos of Parachute Deployments
Betty showed videos of several actual emergency 'chute deployments. One
was successful. Several were not (although all pilots survived). The last
example is noteworthy because of the example it gave of a pilot compounding
major decisions based on bad judgment.
A Hang 2 pilot was known by other local pilots to be a risk-taker,
anxious to be a hotshot aerobatic pilot. On this day he had brought friends
to watch him fly. The site was a tow launch, and the local club members had
not allowed the pilot to fly until very late in the day, and then not until
he promised solemnly NOT to attempt aerobatic maneuvers. Sure enough, once
at altitude he began severe wing-overs and tried a loop, losing control
while inverted. He immediately deployed his 'chute, and it appeared to be a
successful deployment. However, as soon as the canopy snapped fully open,
glider and pilot extended on the bridal, the parachute broke free, and the
glider fell several hundred feet. The pilot was in a coma for two weeks and
needed two years of rehab.
After the accident, safety inspection determined that the pilot had
removed the plastic coating from the glider wires, thinking that this would
reduce parasitic drag on his glider! The uncoated wire had cut through the
parachute bridle with the efficiency of a hot knife! The wire may have been
further roughed up by tiny nicks from the razor he had used on the plastic
coating, a common occurrence when removing plastic sheaths this way.
However, the wire was not inspected for such nicks.
Deploying Your Parachute
Learn these essential steps, rehearse them mentally, practice them:
- LOOK at the handle.
This focus helps you concentrate on the task, and may reduce
debilitating dizziness.
- REACH and grab the handle.
One good technique, especially with gloves, is to run your thumb
down the chest, hook the handle with your thumb, then push out and down.
- PULL the handle.
Get the parachute container out of the pouch, ready to throw.
- Look for CLEAR AIR.
Decide on the direction and timing for your throw.
- THROW into CLEAR AIR, HARD!
If you have no control bar, use both hands. You will get a much
more powerful throw.
- Grab the bridle, if you can reach it, and YANK!
This added force may help load the 'chute with air and speed canopy
inflation. If you have to pull a streaming 'chute back in, yank it as you pull
in hand over hand. Do NOT wrap the bridle and lines around your arms.
- UNZIP your harness.
Prepare for impact: climb into the control frame, feet wide apart.
Once in, try to control the glider with weight shift - you may be able to
exert some control over the landing.
- Locate your HOOK KNIFE.
You will want to cut free from the parachute as quickly as possible
after landing. Some pilots have been injured more by being dragged on the
ground after landing than by the impact of the landing itself.
Practice Deployments
There are three good practice techniques.
- Simulator - hang in a a simulator in flying gear and actually deploy
your chute.
- While flying, practice steps 1 & 2: LOOK at your handle. REACH and grab
the handle. (stop there!)
- Visualization. Use mental imagery to visualize yourself all the way
through a complete and successful deployment, landing, and parachute
disconnect. As a proven training supplement for world class athletes,
repeated visualization exercises actually speed performance! Be sure always
to visualize a successful effort all the way to safe and successful
conclusion.
When you hear about an accident, do not dwell on what went wrong or what
not to do. Instead, visualize what you would do in the circumstances.
When Your Parachute Opens
- Confirm your altitude visually.
- Confirm visually that the 'chute is indeed open.
- Prepare for impact.
- If possible, with control bar intact,climb into the control frame.
With no control bar, prepare for a Modified PLF (Parachute Landing Fall).
Get your feet down, feet and knees together, knees slightly
bent. Tense leg muscles. Tuck arms in close to your body. Think about
trying to stand as you hit ( You will not be able to, but this prepares you
for the impact.) Roll in the direction of the impact or drag.
- If possible, position the glider to hit before you do.
- Have your hook knife ready.
When You Land
- Disconnect from the parachute / glider.
- Deflate the canopy -pull one or two lines from the bottom to dump
air out the top.
- Use your radio. Ask for assistance if needed. Report your condition
& position.
- Signal for help. You may lay your 'chute out or tie it off to give
a visible marker to rescuers.
Problem Causes
THE PILOT
- weak throw
- poor care and maintenance of equipment
advice - pay attention to your rubber bands. replace them
regularly, with the proper strength bands. Note that in older parachute
bags with brass grommets, the brass reacts with the rubber, destroying the
rubber bands over time. Newer bags have nickel or steel grommets.
- waiting too long to deploy.
know the altitude YOUR 'chute needs for successful inflation.
THE SITUATION
- no clear air for throw
- pilot blacking out- possibly from tumble, spin, or head injury
- entanglement of harness or body parts in the glider. Use what you
can to get the chute out and deployed
THE SYSTEM
- bridle routing problems
ballistic systems are notorious for this. If you have a
ballistic deployment 'chute, inspect the routing carefully
If the bridle does not pull apart as designed, from the
harness strap, you may get pinned up against the sail.
- deployment bag / diaper problems
older 'chute containers were wrap-around "diapers'"
replaced in later years by various closing bags. With a diaper, there is no
sequencing of the deployment (desirable is bridle, then lines, then
canopy). This mass deployment is an opportunity for entanglement in the
glider parts.
- bag material... look for nickel or steel grommets rather than
brass. See above from comments on rubber bands.
- Harness design and bag design can be critical to proper deployment.
- IF you put rubber bands on the bridle, leave at least the first 5
feet of the bridle outside the banded region.
Minimizing Deployment Problems
- Inspect your safety system
- Repack often
- change rubber bands 2 to 3 times each year
- if you have dirt or bugs that have gotten in the bag, REPACK.
dirt in the fabric causes abrasion and breakdown
- inspect for smaller holes: one small hole - no big deal; four holes or more - patch them
- Perform the knee test
With the 'chute fully packed, put your knees against the inside
belly area of the harness and pull back hard on the sides of the harness.
Listen for velcro releasing. You are ensuring that your body weight under
load will not accidentally pop the parachute bag out of the harness
container.
MYTH: The old wisdom, taught for years, was, "Never sit on a parachute."
With the coated fabrics used then in canopies, this was a valid warning,
because abrasion could damage the coating and change the canopy porosity.
Modern canopy materials are not coated, so you CAN sit on your packed
parachute. In fact, this may be a helpful way to get air out and have a
good tight pack.
- Upgrade your equipment
- Consider adding a ParaSwivel to the bridle. This lets a glider spin
without twisting the lines.
- Replace older tubular bridal lines with flat TYPE 18 webbing. The older
tubular webbing tears across too easily if nicked, while the newer flat
webbing is very tear-resistant.
- Be aware, webbing will not necessarily show dangerous wear during
visual inspection, and there is currently NO non-destructive test known for
webbing strength. Decide on replacement based on discoloration and nicks.
- Inspect the harness, bridle routing, safety lock, container closure,
carabiner, hang strap.
- PREFLIGHT ALL PARTS of your emergency reserve parachute system.
PARACHUTE MOUNTING POSITION
The choice has been side or chest, and much discussed. Consider, though -
chest mount gives valuable body padding protection in non-deployment
impacts. It also ensures the parachute handle is equally accessible to
either hand.
Evolution of the Hang Glider Reserve Parachute
Earliest goal - make an accident survivable!
Design was for light weight, low bulk, and the ability to deploy at
40 mph.
During the 1970's, adequate parachute material was not reliably
available. There would be significant variation in quality between fabric
runs. Left-over and discarded parachutes from the sky-diving community
found their way, dumped, into the HG market.
1997 HG Reserve 'Chute Requirements
- Light weight
- Pack into existing harness containers
- Slow rate of descent
- Minimal altitude loss for full inflation
- Ability to open with a slowly descending suspended weight (e.g. a
glider spinning and thus falling very slowly)
- Ability to withstand high-speed deployment (90+ mph)
Evolution of Shapes
- Flat circular canopies
- displayed a maximum drag coefficient of 0.70
- Conical
- better drag coefficient (~0.80)
LOTS more material needed
less oscillation than flat circular during the fall.
- Tri-conical / polyconical
- increased drag coefficient further, to ~ 0.85
added extended skirts, causing less air dumping (which allows
acceleration each time air dumps out)
- Advanced shapes
- more design with extended skirts
- Pulled-Down Apex (PDA)
- drag coefficient now up to 0.85
early models were LESS stable than predecessors, with more oscillation
- High Tech Shapes
- These designs result in drag coefficients above 1.0 by designing
for maximum drag and adding airfoil lift elements to the design. One such
design, the Quantum Series, is referred to as Round Air Foils (RA).
Development of deployment bags
Early 'chutes were packed directly into the harness container.
Diapers provided a wrap-around closure for the chute and lines, popping
completely open upon deployment.
Bags have evolved into 2-compartment designs, separating canopy and
lines, giving a controlled sequence to the deployment.
Ballistic deployment devices
Early problems included mounting position and bridle routing difficulty.
Lines get too bound up in the system.
Design changed to holster-style handle mount - but this may not be
accessible to either hand.
1996 Deployment Statistics
13 HG Reserve Parachute deployments
- 3 ballistic devices, accidental deployment
- 1 ballistic deployment, not successful
- 3 hand deployments with problems
- 7 hand deployments otherwise uneventful and successful
Deployment Causes
The MAJOR cause of needing a parachute in a hang glider is aerobatic flying!
The next most common cause is turbulent conditions,
Last year was unusual in having two mid-air collisions.