Specific Risks in Sport Parachuting
Dave Wilkie
Skydive Express
Western Australia
July 2005
This document is comprised of a number of brief outlines of specific risks
associated with sports parachuting. The scenarios outlined here have caused
serious and often fatal injuries to skydivers either here in Australia or
elsewhere in the world. These scenarios are presented here with the intention of
increasing awareness of these specific risks, promoting discussion and hopefully
reducing the incidence of adverse outcomes.
Equipment
Failure to cock the pilotchute
This can result in a pilotchute in tow or a bag lock malfunction. The low
drag of the uncocked pilotchute may not be sufficient to clear the bag lock
after cutaway. Both the pilotchute in tow and the bag lock have the potential to
result in a main/reserve entanglement.
Check the mark on the kill line when closing. Green means fully cocked.
Kill line too short.
Friction will cause the kill line to shrink over time. This means the
pilotchute will remain partially collapsed even when cocked. This has the same
potential problems as an uncocked pilotchute.
Check inside your pilotchute to see if the kill line is pulling down the apex
when cocked.
BOC too loose.
This can result in a premature opening on exit or in freefall. On exit this
can cause impact with the aircraft tail plane. In freefall it can cause impact
with any jumper above. Premature openings in high-speed freefly body positions
can be hard enough to kill the jumper and/or severely damage the equipment. If
you are a freeflyer your BOC pouch is the most important part of your equipment.
Have it replaced at the first sign of looseness.
Main closing loop too long.
This can result in a premature pack opening on exit or in freefall. Adverse
outcomes include impact with the tail plane; impact with any jumper above and
horseshoe malfunction with the risk of a main/reserve entanglement.
Keep your loop short enough to ensure a tight closing pin. If it looks worn
replace it.
Steering lines worn.
These need replacement before other lines as they wear on the guide ring and
on riser velcro. The line below the brake set loop suffers most and is untested
by opening shock. This means it will break at the worst possible moment; when
you are digging yourself out of a low turn. Brake lines also shrink with use
which changes the flight and opening characteristics of the canopy. Most
significantly short brake lines make a canopy easier to stall.
Have a rigger inspect your brake lines and remove any velcro from the risers.
Bridle covers, riser covers and pin protector flap
security.
Poor condition of these components can result in premature openings or
horseshoe malfunctions. This is especially true for freeflying where high
airspeed directed onto the container will tear open anything loose.
If in doubt ask a rigger to inspect your gear especially if attempting
freefly maneuvers.
Reserve and cutaway handle security.
The velcro on these handles can wear out risking floating handles that are
hard to find when you need them as well as accidental cutaway of the main or
premature deployment of the reserve on exit or in freefall.
Lack of 3-ring maintenance.
This can result in a hard or impossible cutaway. If you are unable to cutaway
you have the options of landing a malfunction or deploying the reserve without
cutting away risking a main/reserve entanglement or a down plane. These are very
poor options. An efficient cutaway system is essential for safe parachuting.
Check your 3-ring configuration, cutaway cable length and follow the
recommended monthly maintenance plan.
Aircraft
Single point restraints.
Failure to use these in large aircraft has resulted in multiple fatalities in
forced landing situations when those at the back of the aircraft are slammed
into those at the front crushing them. Restraints can also prevent the occupants
sliding towards the rear and causing the aircraft to stall and crash. Helmets,
especially those with cameras can become lethal weapons in a forced landing.
These should be on your head or on a restraint.
Buckle up for take off, landing and flight below 1000 feet.
Tail plane strike.
A large twin engine or turbine engine aircraft has a high airspeed with the
potential to cause an exiting jumper to hit the tail plane. This can result in
serious or fatal injuries. Don’t exit until you have the permission of the pilot
either verbally or via a light system such as green light for go. Up to that
point the pilot is reducing the airspeed and changing the aircraft attitude to
dip the nose and raise the tail. Even then be careful not to launch up and into
a high lift position. This is especially true if wearing a baggy jumpsuit or
camera wings. Birdman suits have been known to provide enough lift to take the
jumper over the top of the tail.
Assume a low, no lift exit position.
Premature openings.
These can result in impact with other jumpers or the tail. A tail strike can
disable the aircraft. Take care not to allow your main or reserve pins to
contact the edge of the door on exit especially when backing out or head
jamming. Be careful when taking grips not to inadvertently grip the main or
reserve handle of another jumper.
If you have an opening outside the aircraft exit immediately to reduce the
risk of tail plane strike.
Cypres on during descent.
This can result in a reserve opening and possible extraction from the
aircraft at low altitude. This is catastrophic for the jumper, the aircraft and
its remaining occupants. Student cypres’s are more likely to fire on descent due
to their lower activation speed.
Switch off your cypres on descent and close the in-flight door.
Too close on exit.
Different groups or individual jumpers exiting the same aircraft on the same
pass must leave sufficient time between exits to prevent collisions in freefall
or on opening. The time between exits depends on the ground speed of the
aircraft. The slower the ground speed the more time needed to ensure separation.
The strength of the upper wind is the main variable affecting aircraft ground
speed. Typically those opening highest, student, tandems and CRW, exit last.
Freeflyers add an extra factor to the exit order as their shorter freefall time
means they have less freefall drift than flat flyers. Freeflyers usually exit
after flat flyers opening at the same height if there is significant freefall
drift.
Aircraft Strike
Skydivers risk collision with any aircraft passing below the jump aircraft
during the freefall or canopy descent. Prevention methods include radio contact
between the jump aircraft and others in the area, radar monitoring of air space
by air traffic control and visual checks of air space below by the jumper
spotting the aircraft.
Do not exit until given permission by the pilot either verbally or by a
signally system.
Aircraft Hookup
Skydivers exiting aircraft have been known to find themselves hooked up to
the aircraft by things such as boosters, single point restraints, tandem
drogues, static lines, part of the parachute harness or an accidentally deployed
canopy. A sharp knife is normally kept in the aircraft to cut free someone in
this situation. Additionally jumpers often carry hook knives. A main canopy hook
up can be cutaway using normal emergency procedures.
Cutting part of the harness is not a feasible course of action. The only real
option if hooked up by the harness is to try to get back inside the aircraft.
This may not be easy. At least one jumper has remained attached and dangling
below the aircraft during landing. He survived by skidding along on his rig,
friction burning away most of it.
Landing Aircraft
Jump aircraft and parachutist sometimes land at the same time. To avoid
collision do not land on the active runway. Avoid crossing the runway below 500
feet.
Catastrophic aircraft failure.
This is a situation requiring emergency exit from an aircraft that is going
to crash. A disabled aircraft can generate centrifugal forces making exit
extremely difficult. These forces can also slam shut certain types of in-flight
doors.
Have a plan for your emergency exit. If exiting below 1500 feet it is
advisable to deploy the reserve rather than the main.
Freefall
Freefall collisions.
Failure to judge a dive towards a formation or inattention to other jumpers
while diving or tracking can result in collision. Cloud can reduce visibility on
approach or break off. Freeflying presents extra risks of collision due to its 3
dimensional nature, high degree of difficulty, high freefall speed, and the
phenomenon of “corking”; a sudden reversion to a flat position and loss of
vertical speed. Freefall collisions can be severe enough to cause fatal
injuries. Additionally a jumper may be knocked unconscious or be physically
disabled and unable to deploy or operate a parachute.
Choose the type and size of loads that are suitable for your skill level.
Move cautiously towards the formation staying in your quadrant. Look around for
other jumpers on approach and break off.
Poor tracking.
Tracking is essential to ensure adequate separation between jumpers on
opening. A poor track can result in collisions between canopies or between a
canopy and a jumper still in freefall.
Don’t attempt larger formations until your tracking is proficient enough to
deal with the situation.
Tracking into other groups.
Groups exiting on the same pass need to allow enough separation to prevent
jumpers from different groups tracking into each other. Allow extra separation
if break off is unusually high. Be aware of aircraft run in direction. Tracking
along this direction increases the risk of conflict with other groups. Ninety
degrees to run in is the safest direction to track.
Low on a formation.
A jumper who goes past a formation in freefall and then deploys below them
risks a lethal collision with one or more of those still falling.
If you find yourself below a formation at break off track as hard and far as
you can and deploy at the lowest legal altitude. Under no circumstance open
high.
Deployment
No pull.
Believe it or not lots of skydivers have died without pulling the main or
reserve handles. Reasons for this include loss of height awareness, using
borrowed or unfamiliar equipment, sensory overload, hard pulls, drug or alcohol
use or physical incapacity. Night jumps are especially prone to loss of height
awareness due to lack of visual information from the ground.
The use of audible altimeters and AAD’s has greatly reduced the occurrence of
no pull events.
Low Pull.
Low deployments have the same causes as no pulls. A low pull can be the start
of a catastrophic sequence of events. Low main pull, main malfunction,
indecision due to low altitude, low cutaway, insufficient height for reserve
inflation, impact. A low opening of the main can also cause the cypres to fire
risking a main/reserve entanglement or a down plane. In a belly to earth
position the cypres will fire at 750 feet. In a feet to earth position induced
by an opening canopy the cypres will fire higher, possibly above 1000 feet.
Unstable deployment.
A parachute has the best chance to open when deployed from a stable belly to
earth position. An unstable deployment risks hard openings, line twists and
various types of malfunctions including the horseshoe malfunction. A horseshoe
may not clear on cutaway leading to the risk of a main reserve/entanglement or
down plane.
Remember the skydivers’ mantra. In order of priority: Pull. Pull on time.
Pull stable.
Shoulder Dislocation
The normal freefall position puts enough pressure on the shoulder to cause
dislocation especially in individuals with a history of shoulder weakness.
Dislocation makes deployment and operation of the canopy extremely difficult.
Seek medical advice if you have a history of shoulder injuries, particularly
dislocation.
Malfunctions
Total malfunction.
This is surprisingly common. See the no pull item above. Familiarity with
your gear and a careful, even folding of your pilot chute are the best ways to
avoid a total.
Pilot chute in tow.
Incorrect routing of the bridle of a throwaway pilot chute can result in it
towing from the unopened main container. An uncocked pilot chute can also fail
to open the container or lift off the D bag. A tow has the potential to tangle
with the reserve.
Check the bridle routing before every jump.
Baglock.
This is another high-speed malfunction that usually but not always clears on
cutaway. Attention to your pilot chute and line stows is the best way to prevent
a bag lock.
Horseshoe.
This involves some sort of hookup of the canopy preventing its normal opening
and reducing the chance of full separation on cutaway. Causes include unstable
deployment and lines hooking on closing loop tabs or helmet camera mounts. A
horseshoe has the potential to cause a main/reserve entanglement.
Rotating Canopy
One of the most common symptoms of a malfunction is a rapid rotation or spin.
This can be caused by a line over, broken line, line entanglement or canopy
damage. Highly loaded or elliptical parachutes can also spin if they open with
line twists. Any rotating canopy will have a very high descent rate. Emergency
procedure can be complicated by the possibility of a hard cutaway.
Attention to line condition, tension and placement (all lines, especially
steering lines, in the center) during packing can reduce the chance of a
rotating canopy malfunction.
Induced Line Twists
It is possible to induce line twists in an open canopy by over steering. If
the canopy is turned faster than its load can follow a twist will result. Very
deep steering input or a sharp turn one way then the other can cause line
twists.
This is extremely dangerous as the twist might result in an uncontrollable
spin at a low altitude. The jumper is then presented with the choice of a low
cutaway or trying to clear the twist before impact. There may not be enough
height for either.
Canopy on Backwards
Inexperienced jumpers may inadvertently hook up a main canopy backwards. Do
not try to land this as the risk of injury is extremely high.
If in any doubt have a rigger check your canopy before packing it.
Line over.
This involves an inversion of part of the canopy through the suspension line
or more commonly the brake lines. It can result in a rapid rotation. Any
rotating canopy can potentially cause a hard cutaway and/or unstable reserve
deployment.
Keep arching through the spin to ensure a belly to earth position after
cutaway. Use two hands to cutaway if one is not strong enough. Pay attention to
your brake line during packing to keep them from slipping over the front of the
canopy.
Line entanglement.
Also known as pressure knots, entanglements can cause a canopy to rotate with
the same potential issues as a line over.
Severe line twists.
Highly loaded elliptical canopies are prone to line twists. These canopies
can rotate rapidly in twists and hard cutaways are not unusual.
A stable body position with shoulders level right through the opening is the
best way to prevent line twists.
Damage.
Hard openings can cause canopy damage, broken lines and even broken risers. A
broken or prematurely released riser on the RSL side can cause a reserve
deployment and possible main/reserve entanglement.
Steering Failure
A broken steering line or improperly attached toggle can prevent normal
steering of an otherwise open canopy. Such a canopy can be steered and landed on
rear risers if the jumper is confident to do so.
Be very careful flaring on rear risers. Only pull a little as it is very easy
to stall using rear risers.
Reserve Malfunction
A small, highly loaded reserve can open with line twist and rotate. In this
situation the only option is to kick out and gain control as soon as possible.
In the event of a line over or line entanglement pump the brakes to try to clear
it and endeavour to keep the canopy flying straight on landing.
Use a rig with a reserve big enough to fly straight in line twists and land
you safely if you were unconscious and had an AAD fire.
Dual Canopies
Both the main and reserve can be open at the same time if the main is
deployed around AAD firing height. Problems with the RSL, reserve loop, reserve
pin or handle security or inadvertent manual reserve deployment can also result
in dual canopies.
While large, docile and similar sized canopies (student canopies) may fly
together safely, especially in a bi-plane, high performance canopies probably
will not.
A cutaway from a bi-plane risks a main/reserve entanglement. If you elect to
cutaway check that the reserve is fully open and functional. Make sure it is
clear of the main. Two canopies in a bi-plane can be pulled apart into a side-by
side before cutting away.
If the canopies fly apart into a down plane, cutaway immediately.
If the main opens first there may not be enough airspeed to inflate the
reserve. It may twist or entangle with no possibility of inflation. Do not
cutaway the main. Fly and land it as best you can.
Emergency Procedures
Cutaway Failure
This refers to the failure to complete emergency procedure by pulling the
reserve handle following cutaway from a malfunction. Standard emergency
procedures involve gripping the cutaway with the right hand and the reserve
handle with the left before cutting away. This reduces the risk of failure to
locate and pull the reserve handle after cutaway.
This one hand on each handle procedure carries the additional risk of
inadvertently pulling the reserve handle first. In the event of a hard cutaway
the reserve handle must be released to allow a two handed pull. Care must be
taken not to pull or dislodge the reserve handle in the stress of a malfunction
and hard cutaway. A floating reserve handle can be difficult to locate.
The widespread use of RSL’s and reserve AAD’s have reduced to incidence of
fatal cutaway failure.
Hard Cutaway
This can be caused by a deformed or misaligned 3-ring release, friction of
the cutaway cables through the bendex tube or even extremely secure velcro on
the cutaway pad. Inspection and maintenance of the cutaway system should be
performed monthly. A peeling action is the best way to take a pad off the
velcro.
A rotating canopy, especially with line twists is probably the most common
cause of a hard cutaway. In this situation the risers torque the 3-rings
increasing the load on the loop that the cutaway cable passes through. This
makes it hard to move the cable. Additionally line twists may extend down the
risers to the point where the ends of the cutaway cables are caught in the
twists and held securely. Some risers have hard housings fitted to reduce this
risk.
The 3-ring release comes in two sizes, standard and mini. Mini rings have
become the industry norm purely for reasons of fashion. Standard rings are far
superior in preventing hard cutaways due to a much higher mechanical advantage.
Student and tandem systems are fitted with standard rings. A handful of sensible
sports jumpers order their new rigs with standard size rings. The rest are at
higher risk of hard cutaways.
A rotating malfunction followed by an impossible cutaway is a disastrous
situation. The jumper must try to pull the cutaway with two hands as long as
height allows. If too low to cutaway the jumper’s best option is to try to clear
the twists and control the canopy. Deploying the reserve without cutting away is
an absolute last resort.
Floating Handles
Either the cutaway or the reserve handle could be dislodged and so be
difficult to locate and grip when needed. The best way to locate a floating
handle is to follow the bendex tube from the shoulder to the point where the
cables emerge and then take a grip on the handle or the cables.
Floating handles can also cause premature reserve deployment or cutaway. If
aware of a floating reserve handle in freefall the best option may to track away
from other jumpers and deploy the reserve.
If aware of a floating cutaway be prepared for one or both risers to release
on main deployment. Emergency procedures need to be completed.
If the main deploys normally ensure that the cutaway handle is secured and
sufficient cable extends beyond the loop to prevent riser release.
Canopy
Canopy Collisions
Collision between two open canopies can cause direct physical injury to the
jumpers involved. Additionally the canopies can entangle and collapse requiring
cutaway and reserve deployment. Incapacity due to injury may prevent a
successful cutaway. A low altitude may prevent a successful reserve deployment.
Extreme caution must be taken to avoid collisions. Try to locate every other
canopy on the load. Look before turning. Follow the standard circuit pattern and
landing direction. Do not spiral near others or make sudden erratic turns within
the circuit.
Induced Malfunctions
Over steering or deliberately inducing a dynamic stall in a highly loaded or
elliptical canopy can result in an induced malfunction. As this is likely to be
below normal opening height it is more dangerous than other malfunctions as
altitude may not be sufficient for emergency procedures and full reserve
deployment.
Treat high performance canopies with respect when packing, deploying, flying
and landing.
Landing
Low Turns
Low turns are the major cause of parachuting injuries. These include serious
and fatal injuries. Deliberately turning close to the ground to increase
airspeed for a swoop landing is a common practice among experienced jumpers.
Misjudging such turns can be fatal. Less experienced jumpers sometimes attempt
swoop landings without the knowledge or skill required.
If you want to swoop you should
- Wait until you have the necessary experience.
- Have a thorough course of instruction from an experienced swooper.
- Ease into it slowly with small turns and large canopies.
- Be prepared to risk your life and well being for a few seconds of thrill.
Long Spots
Returning from a long spot is a classic scenario for poor landings. Bad spots
lead to indecision and this can lead to low turns, down wind landings or
collision with hazards. Every jumper needs to have a set circuit plan in mind.
If a bad spot does not allow this to be performed at the planned landing target
then it should be done at an alternative landing area. Make a decision as soon
as possible. Turn into wind at a planned height such as 200 feet not necessarily
at a planned location over the ground.
Stall
A high flare can result in a stall and hard landing. Highly loaded and
elliptical canopies stall more easily and radically than larger rectangular
ones. Approaches in brakes that slow the airspeed of the canopy also increase
the risk of stall.
Know your stall point and practice controlled stall recovery at height. Be
prepared to roll on landing.
Down Wind Landings
Failure to check the windsock or formulate a flight plan before jumping can
result in a down wind landing. Check the wind before boarding the aircraft and
again after opening. Watch other canopies land. Have a plan for set up points at
2000 ft, 1000ft, 500ft and 200ft. Landing direction should be determined before
boarding the aircraft not on finals to land.
Hazards
Collision with buildings, trees, power lines or any other hard object can
cause serious injury. Indecision, bad spots, unfamiliar landing areas and strong
winds can result in landings near hazards. Always plan a landing with plenty of
open space in front of you and behind you as well. Avoid flying towards corners
that box you in.
Turbulence
Mechanical turbulence on the downwind side of large ground feature can cause
a parachute to collapse and cause serious injury. Willi-willis (also known as
dust devils or whirlwinds) can have an even more catastrophic effect.
Think very carefully before deciding to jump on windy days or hot conditions
conducive to willi-willis. Just because others are jumping does not mean you
have to be reckless as well.
Collision With Spectators
An incoming parachutist has enough speed to kill a spectator or other jumper
on the ground. For this reasons most drop zones have distinct boundaries between
landing areas and spectator areas. Respect these boundaries. When walking back
from a landing, look out for incoming canopies. If a collision looks immanent it
is the parachutist who should turn and the person on the ground who remains
still. Drop to the ground and lay flat if evasion has not been effective.