What To Do When the Wind Picks Up
As a student skydiver you are guided by your instructors, drop zone management and USPA's Basic Safety Requirements (BSR's) as to the maximum winds allowable for you to safely jump. However, after you graduate from student status and become a USPA "A" license holder, there is no requirement or recommendation concerning wind speeds. And after you purchase your own gear, drop zone management will no longer need to worry about the gear that you are renting from them. From that point on, the decision to jump or to stay on the ground will be a decision that you will be making for yourself.
The following article describes some of the things to consider when you find that someone has turned the big fan on "high".
Before the Jump:
You will find that the maximum winds to jump in is a very individual decision and depends on the jumper's experience, attitude, main canopy size and type, and reserve canopy type. Do not base your decision on what you see more experienced jumpers do because their situation is different, and do not allow yourself to be talked into jumping in winds that are not appropriate for your level of experience and your gear.
It does however help to watch more experienced jumpers land when you are deciding whether or not to jump yourself. Watching someone that is your weight and has similar gear will give you a good idea of what to expect on your landing, assuming the wind does not increase any further.
In addition to getting the wind speed in miles per hour from a wind meter or other source, you can go to the landing area and observe the winds for a while, noting in particular the gustiness present in that area. With experience you will be able to judge the wind that you can jump in by how the wind feels.
Sometimes a lull in the wind may fool you into thinking that the winds have subsided enough to safely jump, but you should observe the winds for at least 5 minutes before coming to that conclusion because another period of increased wind and gusts may follow a lull.
If you in fact decide to make a jump when the winds are strong, protect yourself in the event that some unexpected problem arises by wearing adequate head protection and foot protection.
After Opening:
After your canopy opens and you have begun to fly back to the landing area is the time when you may first begin to realize that the wind has picked up or is much stronger than you were prepared for. As soon as you realize that this has happened, get turned into the wind and check your speed across the ground. If you are backing up there is a good chance that the wind is also very high on the ground. If you have a reserve static line system (RSL) on your rig you may want to disconnect now in the event that you have to release your main canopy.
Pulling down on your front risers will increase your forward speed and may help you make it back or at least keep you from backing up as far, but using your front risers also increases your rate of descent, so you will have to use your best judgement as to whether this is really helping you or not.
If you do not think that you will make it back to the normal landing area, this is the time to make sure that wherever you do land will be a large clear area. It is especially important not to land behind anything like a tree line or a building. The stronger the winds are, the more turbulence is generated downwind of large obstacles like these. It may be necessary to turn and fly far downwind to get to a suitable area.
Approach to landing:
As you get closer to the ground there will probably be slightly less wind, but it will be more turbulent, especially if the terrain is anything but completely flat. Your canopy will be more stable if you hold partial brakes. Your arms can act like "shock absorbents" by relaxing some of the tension on the brakes when the gusts come along.
Holding some brakes will cause your canopy to fly slower and may even cause you to back up, but this may be better than risking having your canopy collapse. At this point you will be comforted by knowing that you have planned ahead well enough to have chosen to land in a large field with a lot of room behind you in which to back up.
Landing:
It is usually recommended that you not front riser or turn sharply near the ground when there is turbulence present. This has been known to cause canopies to collapse.
Smaller canopies are much more sensitive to small steering changes and to gusts so concentrate on keeping the canopy directly into the wind.
You may not need to flare as much as when there is less wind but you must still flare. The main thing to avoid is flaring fully just as a gust occurs. A gust could create enough extra lift to make you go up suddenly and then let you down hard when the gust subsides. Use your judgement and your feel of the canopy to determine just how much to flare and prepare for a parachute landing fall (PLF).
After landing:
The best advice that can be given here is what we have heard many times as students: Pull down on one toggle, and keep pulling it in until you have canopy in your hand, then run around to the downwind side of you canopy.
Even if you have a good landing it is still possible for your canopy to stay inflated and to pull you over and onto the ground. You can usually prevent this by quickly turning around and running downwind with the canopy while it is deflating. If you begin to fall down after landing do not reach out with your hands to break your fall because of the possibility of injuring your arms. Concentrate instead on getting your canopy deflated and do a PLF if necessary, or let the seat of your jumpsuit take the action.
If it has become extremely windy or gusty when you land and you are certain that you will not be able to land without being dragged you have one last resort, and that is to pull your cutaway handle to release your main canopy. This of course assumes that you have disconnected the reserve static line (RSL) system and that you are not jumping a single operation system (SOS) that pulls the reserve handle at the same time you cutaway.
Do not let your fear of re-connecting your canopy prevent you from releasing it if you really need to. It is not a big deal to release your canopy and it is not very hard to properly re-connect it to your rig. You or your rigger probably do it every reserve repack anyway to test the release system. Quite often a canopy that is released in this manner will land with the risers laying out across the canopy and can be easily straightened out. You may even be able to re-connect it right where you land. Just be sure to have the release system inspected by a rigger and do a good line check before packing.
If you decide to release your main canopy, the best time to do it is when you find yourself off balance and know you are going to fall down. If you do this promptly you will simply fall down and not be dragged. You may not even get very dirty! However, if you wait until you are being dragged across the ground by your canopy you may be dragged into a position where you cannot reach your cutaway handle.
Once you are being dragged, you are in very bad situation and must do whatever is necessary to get the canopy under control. At this point you will be glad to know that you planned ahead well enough to not be upwind of a paved surface or a barbed wire fence.
After everything is finally under control be sure to gather up your canopy tightly to prevent the wind from re-inflating it. Remember, the jump is not over until you are back in the packing area with your gear off.
In Your Spare Time:
Read your canopy owner's manual! It has a wealth of information in it and contains information on your canopy's flight characteristics. Some manufacturers even have advice on flying your canopy under adverse conditions.
Skydiving Glossary
This glossary of skydiving terms accompanies the Student Skydiver's Handbook, by Bryan Burke.
Click on the letter corresponding to the first letter of the word you are looking for:
A B C D E F G H I
J K L M N
O P Q R S
T UV W XYZ
Return to the top of the Glossary to search for more words or just browse them alphabetically.
The Letter A
AAD. Automatic Activation Device. A device that senses rate of descent and altitude and which will attempts to mechanically activate the reserve parachute if the skydiver passes below a set altitude at a high rate of descent.
A/C. Aircraft.
Accuracy. Also known as Precision Landing, this is a competition discipline in which the skydiver attempts to land on an established target. At the National level the target is 3 cm in diameter, about the size of a quarter. Accuracy landings of various difficulty, from 20 meters to 2 meters, are required for USPA licenses. See the SIM for details.
AFF. Accelerated Free Fall. An AFF student receives training on freefall jumps of 40 seconds or longer, accompanied by a qualified jumpmaster,
as opposed to Static Line training which does not involve long freefall in the initial training phase.
AGL. Above Ground Level. Altitudes are in reference either to Ground Level of Sea Level (see MSL). Skydivers always use AGL when referring to
altitude.
Airspeed. The speed of a flying object through the air, commonly used in reference to aircraft or canopies.
Altimeter. A device indicating altitude.
Angle of attack. The angle at which the wing is presented to the apparent wind. With square parachutes this changes when the brakes are
applied.
Angle of incidence. The angle at which a canopy is trimmed to glide through the air.
Apparent wind. The wind perceived by an observer. See relative wind.
ASP. Skydive Arizona's version of AFF, the Accelerated Skydiving Program includes two tandem jumps and an enhanced version of the AFF
syllabus.
ASTRA. An AAD made by FXC Corporation.
Aspect ratio. The ratio of a canopys width (side to side) to breadth (front to back). Seven cell canopies typically have an aspect ratio of about 2.2 to one, while nine cell canopies are usually between 2.8 and 3.0 to one.
The Letter B
Backslide. To move backward in freefall relative to a neutral reference. Usually unintentional and undesirable, caused by poor body position.
Bag. The deployment bag in which the canopy is packed.
Base. The core around which a formation skydive is built. Can be a single person or a group of people, depending on the number of skydivers involved.
BASE jump. A jump made from a fixed object rather than an aircraft. BASE is an acronym for building, antennae, spans (bridges) and earth
(cliff).
Beech. Short for Beechcraft, an aircraft manufacturer. Usually used in reference to a Beech D-18, a.k.a. Twin Beech. At one time these were common skydiving planes, but they are becoming obsolete.
BOC. Bottom of Container. Refers to the location of the pilot chute. An increasingly common position for main deployment devices, as opposed to belly or leg mounted.
Body position. Ones freefall body posture. Variations in body position are what make a wide range of freefall maneuvers possible.
Boogie. A gathering of skydivers, usually focused on fun rather than competition. Big drop zones host several boogies a year, often on long holiday weekends.
Bounce. To land at unsurvivable speed. Also to frap, or go in.
Box man. A neutral, face to earth body position in which the arms form right angles at shoulder and elbow, and the legs are spread at about 45 degrees from the long axis and bent 45 degrees at the knees. Generally considered the ideal position for Formation Skydiving.
Brakes. The brake lines of the canopy are synonymous with steering lines. Used together, they slow the parachute. Used independently they result in a turn.
Break off. To cease formation skydiving by tracking away from the formation prior to deployment.
Bridle. The thin webbing strap from the pilot chute to the top of the canopy. Part of the deployment system which consists of pilot chute, bag and bridle.
BSR. Basic Safety Requirements. BSRs are USPA guidelines. They do not have force of law but are generally regarded as excellent minimum safety standards.
Burble. The area of turbulence behind an object going through the air, whether a person in freefall or a canopy in flight.
The Letter C
Call. The time remaining until you are to board the aircraft. For example, a fifteen minute call means you will board in fifteen minutes.
Canopy. The construction of fabric and lines used to land safely after a freefall. Usually used in conjunction with a type reference (round, square, zero-p, main or reserve).
Cascade. The point where two lines join together so they run smoothly into one. Cascading the suspension lines results in reduced bulk and drag.
Cell. Square canopies are made up of pressurized cells, usually seven or nine. Each cell consists of a load bearing rib at each side to which the suspension lines are attached. A third, non load bearing rib runs down the middle of the cell. The cell is pressurized through the open mouth at the front and also through cross ports in the ribs. Adjacent cells share load bearing ribs.
Center point. The point around which movement takes place. In an individual the center point is considered to be in the middle of the torso. In a group, it is the point that the formation centers around.
Cessna. An aircraft manufacturer. Single engined Cessnas such as 180s, 182s and 206s are the workhorse of smaller drop zones, carrying four to six jumpers.
Chute assis. French for sit flying, or freefalling with one's seat presented to the relative wind.
Closing loop. The small loop that holds the flaps of the container closed once the pin has been guided through the loop.
Coach. A skydiver with some formal training in the art of instructing freefall technique.
Container. The element of the parachute that houses the canopies. Technically, the Harness/Container but usually just referred to as the container.
Crabbing. A canopy is crabbing when it is flown at an angle sideways to the ambient wind, resulting in a path across the ground that is sideways as well as forwards.
Creep. To creep is to practice formation skydiving sequences while laying prone on a creeper.
Creeper. A board equipped with wheels on which a skydiver lays to simulate freefall maneuvers.
Cross ports. Holes in the ribs of a cell that allow air to flow from one cell to another.
Current. To "be current" is to have jumped recently enough to retain proficiency in the sport. Uncurrent skydivers, depending on their experience, must be supervised to some degree when they resume jumping. See the SIM.
Cut away. To release the main parachute, cutting away is a standard emergency procedure prior to deploying the reserve. More properly known as a breakaway, the technique did involve using a simple release system activated by pulling a handle.
CRW. Canopy Relative Work, now officially known as Canopy Formations. CRW involves flying open canopies in close formation, where the pilots actually take grips on each other's parachutes.
CYPRES. A type of AAD. Made by AirTech of Germany, this is the most common type of AAD and the first modern design to be widely adopted by expert skydivers.
The Letter D
DC-3. A type of aircraft, the Douglas DC-3 is a large, twin engined airplane capable of carrying over 40 jumpers. Like the Twin Beech, DC-3s are being rapidly replaced by more modern turbine engined aircraft.
De-arch. To flatten out or reverse one's body position from the normal arched box man. A de-arch results in a slower fall rate than an arch.
Dacron. A common construction material for canopy suspension lines. Dacron lines are thicker and softer than so called "microlines".
Data card. Every parachute carries a data card with information on the reserve parachute, including type, last date packed, owner, serial number, etc.
Dead spider. Slang for de-arch.
Decision altitude. The altitude at which a skydiver is trained to begin execution of emergency procedures. Usually 2,500 feet AGL for students, and 1,800 feet for expert skydivers.
Deployment system. The components of the parachute that control deployment of the canopy. Includes pilot chute, bridle and bag.
Dirt dive. To rehearse a skydive on the ground.
Dive floater. A dive floater is a skydiver who is inside the airplane in the exit line up, but leaving prior to the base. This configuration only occurs on large formations.
Dive loops. Many advanced skydivers have loops or "blocks" on their front risers to make it easy to grip the front risers for steering purposes. Also called front riser loops.
Diver. Anyone diving out of the plane during a formation skydiving exit.
Door jam. To practice an exit in the aircraft door of a mock up of it prior to the skydive.
DOS - Double or Dual Action System
Down plane. A CRW formation with two canopies, both pointed toward the ground. This can also occur to a single skydiver with both main and reserve deployed.
Drop zone. Common slang for a skydiving center, also DZ.
Dytter. A brand of audible altimeter.
The Letter E
Elliptical. A wing shape characterized by a tapering leading and trailing edge so that the middle of the canopy is wider, front to back, than the ends. This configuration is typical of many high performance canopies.
End cell. The cell furthers out on a canopy.
Exit weight. The total weight of the jumper and all equipment and clothing.
The Letter F
F-111. A fabric common in mid range canopies, F-111 is slightly permeable to air and wears faster than zero-p fabric. Pronounced "F one eleven".
FAA. The Federal Aviation Administration is the agency of the US government that regulates aviation activity, including skydiving.
FAI. Federation Aeronautique International. The international organization governing air sports.
FARs. Federal Aviation Regulations, the laws governing aviation.
Fall rate. The speed at which a skydiver falls. Matching fall rate is essential to successful formation skydiving. This is done with jumpsuits, weights and body position.
Finger trap. A method of installing a loop in a brake line without producing rough spots on the lines, the finger trap is accomplished by sliding one line into the other. The loop serves as a method of setting brakes in the desired position for the parachutes deployment.
Flare. The act of pulling down the brakes of the canopy in order to slow it down, resulting in an increased angle of attack and reduced descent rate.
Floater. Skydivers who leave the airplane before the base are called floaters since they must use a slow fall rate to get up to the base. Floating also refers to an exit position outside the airplane.
Freestyle. A type of skydiving characterized by acrobatic individual flying, reminiscent of gymnastics.
FS. Formation Skydiving, formerly known as relative work. In FS, skydivers attempt to go through a predetermined sequence of freefall formations.
Formation. 1) A freefall skydiving formation of more than one jumper. 2) A flight of more than one jump plane.
Funnel. A funnel occurs when one or more skydivers find themselves in an unstable body position and end up in a skydivers burble. The resulting loss of stability for the other skydivers usually causes the formation to break up.
FXC. A company manufacturing AADs. One FXC design is common on students but considered by many to be unsuitable for expert skydivers. A new FXC design, the ASTRA, went on the market in the spring of 1996 and is relatively unknown.
The Letter G
Glide ratio. The distance a canopy flies forward compared to down. A canopy with a 3:1 glide ratio flies three feet forward for every foot of vertical descent.
GPS. Global Positioning System. By picking up signals from satellites, a GPS receiver can tell the user position over the ground. Used in skydiving aircraft to spot the exit.
Grips. Using the hands to hold onto another skydiver in freefall or during the aircraft exits. In formation skydiving, the formations are scored as complete when every skydiver has taken the correct grips.
Grippers. Hand holds built onto formation skydiving jumpsuits to make it easier to take grips.
Ground speed. The speed of an airplane or skydiver over the ground, as opposed to through the air.
The Letter H
Hand deploy. To activate the parachute by manually deploying the pilot chute as opposed to pulling a ripcord.
Harness/container. The webbing and fabric holding the main and reserve canopies to the skydiver.
Heading. The direction an aircraft, skydiver, or parachute is facing. The ability to recognize and maintain heading is crucial to jumping
with others successfully. "On" or "off" heading are terms commonly used to describe exits and deployments.
Holding. When a parachute is flying directly into the ambient wind, it is said holding. See running and crabbing.
Hook knife. A small knife carried in the jumpsuit or on the parachute harness, the hook knife is designed to cut lines or webbing. A small razor blade is recessed in a hook shaped handle to prevent unintentional cuts.
Hook turn. A turn of 90 degrees or more executed close to the ground. Because of the high risk associated with this maneuver, hook turns have an unfavorable connotation.
Hot fuel. When the airplane does not shut down during fueling. Do not board the aircraft while fueling is in progress.
The Letter I
In date. A reserve packed within the previous 120 days is said to be "in date". If more than 120 days have elapsed since the reserve was packed it
is"out of date" and illegal to use.
Instructor. Someone who has held a USPA jumpmaster rating for at least one year and passed an Instructor Certification Course.
IPC. The International Parachuting Commission oversees sport parachuting. It is a committee of the FAI.
The Letter J
Jump run. The flight path taken by the jump plane to put the skydivers in position over the airport.
Jumpsuit. A cover all type garment designed for specific skydiving applications such as FS, freestyle or accuracy.
Jumpmaster. Someone who has successfully attended a USPA Jumpmaster Certification Course. A jumpmaster has all of the privileges of an Instructor except that they cannot supervise a first jump course, sign off licenses, or manage a student program without an instructor's supervision.
The Letter K
Key. A signal to move on to the next step in a skydive.
King Air. A turbine aircraft made by Beechcraft and common in medium sized drop zones.
The Letter L
Line of flight. An imaginary line corresponding to the jump plane's path over the ground, the line of flight is a useful reference line on larger formation
skydives. Also, during the jump run the skydivers will be distributed along this line of flight.
Log book. Like pilots or sailors, skydivers log their activity and achievements in order to document their experience.
LORAN. A navigational system similar to GPS except based on ground transmitters, LORAN is relatively obsolete.
The Letter M
MSL. Mean sea level. Used by pilots when defining altitude, MSL refers to feet above sea level as opposed to above the ground. Pilots always use MSL when referring to altitude.
Main. The primary parachute.
Manifest. 1) The list of skydivers on the jump plane. 2) The act of going to the office where this list is maintained to put yourself on a plane. 3) The location where manifesting takes place.
MARDS - Main Activated Reserve Deployment System
Microline. A modern type of suspension line considerably smaller than dacron line.
The Letter N
The Letter O
Organizer. Someone with leadership skills and skydiving expertise who plans formation skydives.
Otter. The DeHavilland Twin Otter, a very popular turbine jump ship carrying up to 23 jumpers.
Out landing. Landing off target.
Out of date. See in date.
The Letter P
Packing data card. See data card.
Peas. Pea gravel, used in the landing area as a target reference and because it is forgiving of hard landings.
Pin. 1) The skydiver who first gets to the base. Base/pin are the two people around which many formations are built. 2) The act of docking
on the base. 3) The closing pin of the main or reserve container, which should both be checked prior to jumping.
Pit. The pea gravel area.
Pilot chute. A small, round parachute that acts as a drogue to extract the main parachute from the container and deploy it.
PLF. Parachute landing fall. A technique used to minimize injury during rough landings, a PLF distributes the landing shock along feet, calves, thighs, hip and shoulder.
Porter. A single engined turbine aircraft carrying up to ten jumpers.
Post dive. Review of a skydive after everyone has landed.
PRO rating. A USPA rating indicating competence to perform difficult demonstration jumps.
Pull out. A type of hand deploy pilot chute where the pilot chute is packed inside the container and pulled out using a handle with a lanyard to the pilot chute.
Pull up cord. A piece of cord or line used to pull the closing loop through the grommets of the container.
Pud. Slang for the handle on a pull out pilot chute system.
The Letter Q
The Letter R
RSL. Reserve static line. This is a line from the main risers to the reserve cable. In the event the main is cut away, it may pull the reserve pin.
Note: this system is only effective in malfunctions where the main is at least partially deployed.
RW. Relative work, the term used to describe formation skydiving until a change in nomenclature made by the International Parachuting Commission in the early 90s.
Relative wind. The apparent wind felt by a jumper in freefall, relative wind is the result of the skydiver's speed through the air.
Reserve. The auxiliary parachute carried on every intentional parachute jump.
Rip cord. The deployment system on all reserves and most student parachutes. The ripcord is a piece of cable with a handle at one end and a pin at the other. When pulled, the pin comes out of the closing loop holding the container shut, and the pilot chute is released.
Rig. Skydiver slang for the entire parachute, including main and reserve canopies and the harness/container.
Rigger. Someone with a certificate from the FAA stating they have successfully met the requirements to be a parachute rigger.
Rigger's certificate. The certificate possessed by a rigger as proof of competence. Senior riggers may make minor repairs and pack reserve and main parachutes. Master riggers may make major repairs and alterations as well as packing parachutes.
Risers. The webbing that connects the harness to the suspension lines. At the bottom of the risers will be a mechanism for attaching and releasing the risers and harness, usually in the form of a three ring release. On the rear risers are the brakes/steering lines. The suspension lines attach to the top of the risers with connector links, also known as rapid links.
Round. 1) A formation where each skydiver has grips on the arms of those next to him, also known as a star. 2) A round parachute, as opposed to a modern ram-air "square" parachute.
Running. When a canopy is flying with the ambient wind it is said to be running. This produces the greatest possible ground speed.
The Letter S
S&TA. Safety and Training Advisor. The S&TA is a volunteer representative of USPA who attempts to disseminate information about safety and act as a liaison between the DZ and USPA. Most S&TAs hold instructor ratings.
SCR. The oldest award for formation skydiving achievement, for those who have been in a star of at least eight people in which each person left the aircraft separately and flew to the formation.
SIM. Skydiver's Information Manual. Published by the USPA, the SIM is a comprehensive manual on USPA policies and training methods. It also
includes FARs pertinent to skydiving.
SOS. Single Operation System. This system simplifies emergency procedures by combining the functions of the cut away and reserve handles in a
single handle.
Seal. Reserve parachutes have a small lead seal on a piece of red thread around the closing pin. This seal indicates the reserve has not been
opened since it left the riggers hands.
Sentinel. A type of AAD.
Single operation system. See SOS.
Skygod. Although on the surface this term refers to a superior skydiver, in drop zone use skygod is a derogatory term for a skydiver whose ego has grown faster than his skydiving ability.
Slider. A rectangular piece of nylon fabric with a grommet at each corner through which the canopy's suspension lines are routed. Packed at the top of the lines, the slider controls the opening of the canopy by preventing the parachute from expanding too rapidly.
Slot. A position in the skydive or on the plane. Uses: "dock in your slot", or "two slots left on the next Otter".
Spectra. A material from which microline is made.
Spot. The position of the aircraft when the jumpers exit. Spotting duties (selecting the spot) can be done by a skydiver or the pilot.
Square. A ram air parachute as opposed to a round parachute.
Stabilizer. The vertical strips of cloth depending from the end cells of the canopy. Stabilizers improve the canopy's ability to fly straight ahead and enhance efficiency by reducing tip vortices.
Stall. When the angle of attack of a wing becomes too high to sustain lift, the wing is said to be stalled.
Static line. In static line deployments the parachute deployment system is attached to the airplane, with a cord ten to fifteen feet long, resulting in deployment immediately after exit.
Steering lines. The lines that run from the steering toggles on the rear risers to the trailing edge of the parachute.
Steering toggles. Handles attached to the end of the steering lines to facilitate their use. Toggles and lines are configured so they can be stowed in a partially down position to enhance the opening of the parachute.
Stow. To neatly arrange suspension lines on the deployment bag or steering toggles in their keepers.
Style. A type of freefall competition where an individual skydiver attempts to execute a predetermined sequence of maneuvers in the shortest
possible time.
Suspension lines. The lines from the risers to the canopy. They are normally in four groups, labeled from front to back as A, B, C and D. They can be further divided into right and left or front and back riser groups, and by type of material.
Swoop. 1) To dive down to a formation or individual in freefall. 2) To aggressively approach the landing area in order to produce a long, flat flare and an exciting landing.
The Letter T
TAF - Tandem Accelerated Freefall where the 1st 3 or 4 stages are done on tandem and then the AFF one on one jumps are done as per the standard AFF program.
Tandem. Parachute jumps in which two skydivers, usually an instructor and student, share one parachute system. The student is in a separate harness that attaches to the front of the instructor's harness.
Terminal velocity. The speed at which drag matches the pull of gravity, resulting in a constant fall rate. Typical terminal velocity for formation skydiving is in the 120 to 135 mile per hour range, but speeds as high as 300 miles per hour have been reached.
Three ring. A parachute release mechanism that utilizes three rings of separate size in a mechanical advantage system. Invented by Bill
Booth in the late 70s, the three ring release is almost universally considered the best cut away system available.
Throw out. A deployment method in which the pilot chute is stowed in a pouch on the belly, leg of bottom of container.
Toggles. Handles on the steering lines.
Track. To assume a body position that creates a high forward speed. Used to approach or depart from other skydivers in freefall.
TSO. Technical Standard Order. A technical standard that all American parachutes must meet before they can be marketed. Unless specifically
exempted by the FAA, a parachute must have a TSO placard to be legal.
Turn around load. When the aircraft does not shut down between loads, but lands and picks up skydivers for immediate departure.
The Letters UV
Uppers. The upper winds, or winds at exit altitude. The "uppers" are often much stronger and occasionally from a different direction than ground winds.
USPA
The United States Parachute Association is a non profit skydiver's organization. USPA offers guidance and assistance to skydivers in training, government relations, competition, and many other fields. Most drop zones require USPA membership of individual skydivers because such membership includes third party liability insurance.
The Letter W
Wave off. Prior to deployment a skydiver should make a clearly defined arm motion to indicate to others nearby that he is about to open his parachute. A good wave off is essential to the avoidance of deployment collisions.
WDI. Wind drift indicator. A paper streamer thrown from the jump plane to estimate winds under canopy and determine the spot.
Weights. Many lighter skydivers wear a weight vest to allow them to maintain a fast fall rate.
Wuffo. Skydiver slang for people who don't jump, from "Wuffo you jump out of them planes?"
Wind line. An imaginary line from the desired landing area, extending directly along the direction the wind is blowing.
Winds aloft. See uppers.
Wing loading. The ratio of weight born by a wing to its surface area. In the US, divide your exit weight in pounds by the square footage of
the canopy.
The Letter XYZ
Zero-p. Common slang for a type of fabric relatively impermeable to air. The less air that flows through the fabric wing of a ram air parachute, the more efficiently it flies.
Flying and Landing High Performance Parachutes Safely
I. Working on Conservative Approach Techniques
A well planned approach makes good landings easier to accomplish, while most bad
landings come after a poor approach. It follows then, that working on improving a variety of
approach techniques is the first step.
A. Control your canopy with smooth toggle movements.
Fly your downwind, base, and final approach smoothly, keeping control inputs to an absolute minimum. This makes it easier for others to predict what you are doing. The canopy will fly more efficiently, and it also helps to make the canopy more stable in turbulence.
B. Once you're pleased with your landings, experiment with making approaches at
various speeds.
Getting a good landing with less float after the flare will help you land in small areas. Doing this requires a slower approach. But if you are too slow, you will land hard! It takes considerable skill to land softly after a slower approach, so practicing this in an open area is important.
C. Learn how slowly you can approach and still get a reasonable landing.
Again, landing well after a slow approach requires practice and considerable work on flaring technique. How slow you can make a safe approach depends on your wing-loading, the design of the parachute, and how good your technique is. It takes a lot of practice to get good landings after a slow approach, but the result is more options for different landings, and greater safety.
D. Even if you are conservative, learn how to make a straight-in approach using a
small amount of front risers.
Make sure your canopy is very stable in this flight mode first. Just 1 to 3 inches of riser will produce quite a change in the approach speed and landing. By becoming familiar with the slightly higher speeds of this approach, you will
be better prepared should the unexpected happen and you find yourself screaming along after making an evasive maneuver to avoid traffic near the ground.
E. If you are an aggressive canopy pilot and like SWOOP landings, it is very important to practice straight-in approaches at various speeds.
You may have to make a slow approach one day, and you need to stay good at it. You may not even realize how slow you can approach and still be safe. Its better to practice in good conditions so that you are prepared for the worst. Most new canopies can be flown straight in, even at very high wing-loadings, with proper technique. If you can't do it, you probably need to work on technique.
II. Working on High-Speed Approaches
A. Learn when to say no to a high-speed approach.
There are times when high-speed approaches are unsafe, due to heavy traffic in the air or on the ground, when you are angry or tired, when you are disappointed with your performance, or when the weather conditions are marginal. Make sure you err on the cautious side! You can make that swoop landing on a later jump when conditions improve only if you survive this jump!
B. Verify that the technique you wish to use works well with the canopy you are using.
Some canopies have unusual flight characteristics that can take hundreds of jumps to fully explore. Do this exploration up high away from other traffic. Some canopies can
become unstable using certain techniques.
C. Stay with straight-in approaches, working on flaring technique for many jumps to
obtain the longest swoop possible before attempting any turning approaches.
Many people do not work on improving their technique long enough before trying aggressive
turning approaches. Many tend to react too late to changing circumstances, and then over control afterwards. The result is reduced canopy efficiency, which reduces the distance of the resulting swoop. It also indicates that the jumper is over his limit of safety.
D. If you are doing turning approaches, try to develop several different techniques for controlling the rate of altitude Ioss compared to the rate of turn.
1. Over a period of many jumps, find out how much you can vary the altitude loss in a turn by using different control inputs.
2. In these experiments you will find that some techniques will produce extremely high altitude loss with only a moderate rate of turn (Example: Steep front riser spiral).
3. In these experiments you will also find that some techniques will produce low altitude loss, even with a fairly high rate of turn (Example: Carving toggle turn).
E. When setting up for your turning approach, try to set up for a turn that will allow for a great altitude loss with very little turn rate being required.
1. If you're sure you've set up your approach high enough, start the high altitude loss turning technique. As you make the turn, evaluate the altitude loss. Always be
ready to change the turn into one that produces less altitude loss. Starting real high and knowing many turning techniques allows you to have plenty of outs. Try to start all your turning approaches with enough altitude to make the high altitude loss turn safe. Choose the turning method you feel is appropriate. If you notice during the turn that you do not have sufficient safety margin, change the turn technique to one that allows for less altitude loss. Now you have your margin for
safety back again.
2. If you are sure you are too low to try the high altitude loss turn, and even a medium altitude loss turn does not look like a good possibility, consider landing slightly crosswind, if traffic permits. Avoid the low turn! If it looks like you need to start with a low altitude loss turn method, you are in a dangerous situation! If you turn anyway, and you do survive, slap yourself for being so stupid! Vow to never get caught in that situation again! Don't judge your approach technique as good
just because you walked away from the landing!
F. Avoid becoming trapped into the habit of using only one turning technique that requires an exact starting altitude for success.
Favoring one turning technique, especially a low altitude method such as a sharp snapping toggle turn followed by burying both toggles, is very risky. Because the canopy tends to pull out of the dive almost the same way each time, you require an exact starting altitude and perfect judgement each time. Nobody can be that perfect! One day your judgement will be a little bit off, and you will crash. Or you may have some turbulent air, which will affect your approach, and you will crash. Do not fall into the too common trap of thinking that you've completed the learning process! No one has!
G. Learn the concept of the "corner" and stay out of it.
The corner represents the change from a
vertical diving approach to a horizontal swoop. Make that corner as round as possible. (A large
radius pullout started higher is safer than a sharp pullout started lower).
1. If the canopy's natural tendency to pull out gets you to level flight without pulling any toggles at all, then you were not very far into the corner. This is the safer method.
2. If you need to pull the toggles down to get out of the vertical part of the approach before you can start your flare, then you were too vertical too close to the ground! This is better than hitting the ground, but its very dangerous and should be taken as a severe warning. The biggest problem with this is that the average experienced jumper does not
see this as being as dangerous as it really is. Slap yourself for being so stupid, and promise not to get caught like that again. Instead, do everything higher, and start the pullout earlier. Again, the idea is to prevent having to be perfect just to survive.
3. As you can see, the measure of safety on your swoop is how little toggle it takes to get to level flight. If you are pulling toggles down hard and late, you need to start the turn much higher, so that you will need less toggle to pull out of the dive. You may also need to learn how to perceive, far sooner, that you are getting too far into the corner. This way you can apply a little toggle up higher, rather than a lot of toggle at the last instant. In other words, you need to work more on better planning of the approach. Probably a less
steep approach would help!
H. Avoid these hook turn traps.
1. The courtesy trap.
You can only pay so much attention to being courteous to others while under canopy. Do not pay so much attention to others that you forget to leave yourself plenty of safe options too.
2 The dropping winds trap.
This is one example of failing to adjust for the changing conditions as the day progresses. People who have been flying the same downwind approach to the landing area all day tend to get very used to the sight picture that they have. As the wind drops, this sight picture will change, as the wind will no longer be helping you get back to the landing area so quickly. But you may continue to try and fly the old sight picture. If you are getting caught by this, you will feel you are sinking faster than you expected while on downwind, so you try and float in the brakes a bit more than previously. In an attempt to keep the same landing spot as earlier, you may find yourself trying to float downwind a little farther as well. All this adjusting eats up airspeed and altitude, both of which are needed to turn into the wind. If you are also tired from a day of jumping, you might find yourself ignoring these signs, turning too low to survive.
3. The "I'm really Gonna swoop this time" trap.
This is a situation where the jumper is so enthusiastic about his swoop landings, that they forget about everything else! They see their desired approach as the only possibility and will attempt that approach regardless of whether there are problems with traffic, spectators, winds, or turbulence. They forget that other options exist, and are very likely to have an accident.
4. The race horse trap.
Jumper making mistake number three (above) has fallen into the race horse trap. Race horses sometimes wear blinders on their eyes to restrict their vision. Sometimes jumpers pay so much attention to their own approach that they don't see anything else, just like the race horse. Collisions near the ground are often caused by this, so its very dangerous.
III. Working on Improving Landings
A. Altitude control is the key to no-wind landings.
It is not so important to be at an exact
specific altitude when starting the flare, but it is very important how high you are when you finish the flare. You should finish the flare so that you have no rate of descent (or at least your minimum rate of descent) when your feet are at ground level.
B. For the best landings, transfer the weight from harness to ground gently and gradually.
If you are at zero rate of descent with feet at ground level, you can gently press your feet on the ground while you continue to sit in the harness. With the first step, you can remove a little weight from the harness, by stepping only lightly on the ground, and more heavily on the next steps, until all your weight is transferred from the harness to the ground. To do this you must have the zero rate of descent at ground level, not higher. You must also maintain adequate flying speed during this time. No parachute or any other wing is capable of supporting you at no foward airspeed!
C. Be careful to avoid using your hands and arms for balancing or protecting yourself during the flare and landing.
As you will see in the video, the canopy will respond to every toggle movement (or shifting in the harness), even when you are well into the
transition to the ground.
D. Watch the landings of other people and get video of your landings. Look for these
common errors.
1. Lifting one toggle at touchdown.
This is the balance trap. If you feel like you are falling to one side, you may try to stick an arm out for balance, which turns the canopy. You may think it was a side gust.
2. Extending a hand out to protect yourself.
This is the protection trap. By extending your hand out to the ground to protect yourself, you unknowingly steer the canopy that direction.
3. Stabbing the ground with your feet.
This is done usually in anticipation of a hard landing. It hurts the legs and feet, and is usually accompanied by lifting both toggles backwards and upwards, which compounds the situation by causing the canopy to dive harder at the ground.
4. Fighting the wind.
This is letting one toggle come up and pushing the other one down prematurely, in anticipation of difficulties in getting the canopy on the ground in high winds. This can produce some really ugly accidents. Make sure you're really on the ground first, then get the canopy on the ground.
5. Tunnel vision.
Though we try our best to avoid it, all of us tend to concentrate more on our flight path as we get closer to landing time. Sometimes swoopers or
accuracy jumpers start having this problem much higher up. This is very dangerous! Try to keep looking around and seeing people!
6. Flaring too slowly, too high, or too far, etc...
Experiment more while up high. Watch other peoples landings and watch videos of your
own landings. Usually this is a perception problem.
IV. Conclusion
A. Acknowledge your current limitations.
B. Constantly play "what if" situations when you're flying.
C. If in doubt choose the conservative option.
D. Create safe situations for yourself and others.
E. VOW TO BECOME A STUDENT OF CANOPY CONTROL AGAIN.
F. Have fun!
Survival Skills for Canopy Control
Landing Accidents
Avoid landing accidents by doing all you can to eliminate landing off the DZ.
As soon as you're open, evaluate the spot. When faced with a bad spot, quickly find out how far you can go by using the accuracy trick. You can greatly extend your parachute's capability to get you back to the DZ by learning how to use the entire control range to your advantage. The accuracy trick will help you learn how to quickly choose the best toggle or riser position for any bad spot. Why deal with unfamiliar hazards off the DZ? Avoid them through better canopy control.
A. The Accuracy Trick Defined
Find the point on the ground that doesn't move.
1. Choose a point on the ground in front of you. If it seems to move towards you (the angle gets steeper in your field of vision), then you will fly past that point. If the point seems to move up or away (the angle to the point gets flatter in your field of vision), then you won't make it that far, unless something changes. If you keep looking between these two points, you will find one point on the ground that does not appear to move in your field of vision at all. (The visual angle doesn't change.) I call that point the "special point" that doesn't move. The visual angle to all other points on the ground seem to move outward from this point as you travel towards it.
2. If the winds never changed, and you never moved your toggles, you would end up crashing into the ground right on that special point! If the winds do change, you can tell right away because the special point that wasn't moving will start to move as soon as the winds change. That means there is a new point that doesn't move. A new special point replaces the old one. That special point will also start to move if you change your toggle position.
B. Using The Old Accuracy Trick
1. When you have a tail wind and the spot is quite long:
Find the toggle position that would take you to a point furthest past the DZ. Then you will arrive at the DZ with the most altitude (and most options) remaining.
A simple rule such as, "on a long spot with a tailwind, fly half brakes," may be better than nothing, but it is far from ideal. To avoid the off-airport landing, you may need better performance than a simple guideline can give. With a strong tail wind, it is likely that going to deeper brakes will help even more, but how much brakes? Use the accuracy trick to choose what control position works the best in the particular tailwind you have at the time: Find the special point, then add some brakes. See how you have a new special point as you change the toggles? If the visual angle to the new point is flatter, you are doing better. The visual angle to the old point will get steeper and steeper. Now add some more brakes. If your field of vision changes again just as described, then you're doing even better. Each time you change the toggles, (or each time the wind changes), you will have a new special point. Add more brakes. You're flying really slowly now. If the visual angle to the new point is steeper, then you're not doing as well. If this is the case, the visual angle to the old point will get flatter and flatter. So reduce the brakes back to the optimum. 2. If you have a tailwind coming slightly from one side, and you have a long spot, quickly choose the right crab angle to fly a straight path to the DZ.
You've turned towards the DZ and have chosen the best brake position that would take you to a point furthest past the DZ by using the accuracy trick described above. You can draw an imaginary straight line between you and the special point, through the intended landing point. If you start drifting off this line, immediately make a crab angle that will keep you on this line. See how the visual angle to the special point changes as you create the crab angle? Adjust the brakes to put that special point in the best position again. If you were really deep in the brakes, you will probably need less brakes after you create a crab angle.
Do not "home" back to the DZ by pointing straight at it while drifting sideways. Since the crosswind will blow you slightly off the wind line, you will likely readjust your heading again and again to point back towards the DZ, without ever counteracting the crosswind at all. This means you will be flying a long arc back to the DZ. The quickest way back is a straight line, so crab rather than home! 3. What about a headwind on a long spot?
If you have a headwind, the special point that doesn't move will be quite close to you. If you need to fly past this point to get to a safe landing area, you will probably need to use front risers. (Make sure your canopy is quite stable on front risers before using this technique) How much front risers? Use the accuracy trick to find out! Try a little front riser and the special point will move. (The angle will start changing). Try a little more and it will move again. Try a little more. Did the point move the wrong direction? That's too much front riser. See how this method works to determine the best control position in any bad spot situation? How about a headwind coming from slightly from one side?
4. Don't forget to leave yourself plenty of safety margin.
Use the accuracy trick in this way to get back to a safe place, but be careful to avoid fixating on this technique so much that we forget to use our safe options while they still exist. Make sure you leave yourself plenty of altitude and maneuvering room to plan a safe approach and landing.
II. Learn To Fly Defensively
A. Defensive Flying Has Two Basic Parts
1. Developing such high skill that you get to the ground safely in spite of the stupid things people are doing all around you.
2. Developing such good judgement that you make your decisions in a way that helps create safer situations for yourself and others.
B. Stage The Approaches To Avoid Heavy Traffic
Many of the worst accidents are collisions that occur at landing time, often because there are just too many canopies going too many directions to be safe! Staging the traffic can help reduce this risk.
1.To create more seperation from other traffic.
After opening decide quickly whether it is best to float or dive, assuming the spot is good enough to allow for some maneuvering. The goal is to prevent a high frequency of landings occurring in a short period of time. Less traffic density means less chance of an accident. This is similar to the idea that eliminating tailgating reduces the chance of accidents on the highway. To stage the approaches to the landing area, you must look way ahead and predict how the traffic will arrive at the landing area. Then, adjust your fight path so that you have as little traffic as possible when you are landing. The more people on the load using this technique the better! Noticing heavy traffic when you're already on final approach is too late! Planning is the name of the game.
2. How do you stage the approaches?
First, look all around you after opening. See where everyone is. Ask yourself two questions: Are you near the top of the bunch or near the bottom? Is your canopy loaded more heavily or more lightly than the others? Then:
If you're more towards the bottom, and have an average wing loading for the group: You should land as soon as possible. You're trying to stretch out the time period that all the landings will occur by getting the landing process started sooner. If you don't do this, you may start crowding up the traffic behind you, just like a car driver would if he drove slowly in the fast lane.
If you're more towards the bottom, but have a big floaty canopy: The faster traffic will probably catch up and pass you. Where would you prefer this to happen? If you dive down and try to set up on final approach early, you will probably be passed during your final approach. In this case, assuming the spot is good, it might be better to float in the brakes right from the start. This will force the faster traffic to pass you while you are still quite high. Being passed up high is safer than being passed on final approach.
If you're more towards the top: You should try to float in the brakes. You're trying to stretch out the time period that all the landings will occur, by landing later. This is easy if you are on a larger floaty canopy.
What if you're more towards the the top, but you have a high wing loading? If you're loaded heavily, you can still probably float in brakes quite well. Try to stay up with the big floaty canopies, until you find the biggest gap in the traffic that is below you. Then you fly down and fill that biggest gap. That gap is usually just in front of the big floaty canopies.
C. Learn The Habits Of Others
Anticipating the actions of others will help keep you out of trouble.Here are some examples:
1. The indecisive slow poke.
This is someone with a big canopy that likes to do sashays while in the final approach area. If you're flying a much faster canopy, don't follow him on his downwind leg. You may get stuck behind him, needing to pass him on late final. The problem is, you may not be able to predict where he will be when you pass! Better to pass him earlier on, or turn your base leg early, landing more up-wind than him. Perhaps you can land somewhere else. Just don't cut him off, because he might get overloaded by the whole thing and make a mistake, causing an accident.
2. The last-second hook turner.
This guy loves to do low toggle-turns, way lower than you're willing to risk. If you're following him back from a bad spot, don't wait for him to turn into the wind before you do! You'll probably be turning lower than you want to be! If he is following close behind you and below you, he might be obstructing your turn into the wind. Remove yourself from this situation while there is still plenty of altitude.
3. Have you ever known someone who likes landing downwind for fun?
In today's jumping environment, you have to be ready for anything, so keep lots of options open.
D. Diffuse The Hot Landing Area
This you do by taking the initiative to land somewhere else.
Walking is healthy! It's better than being carried back on a stretcher. By choosing to land somewhere else, rather than joining into the already crowded traffic on final to the "cool" landing area, you'll make it safer for yourself, as well as making the "cool" landing area a little less crowded for the others.
E. Check The Spot Early During The Skydive
Many marginal spots are made worse by aimlessly wandering around for a few seconds while figuring out where you are. If you can do so quickly, check the spot during climb out if you're a floater waiting for others to climb out. Check it if you have an idle second or two during freefall. Checking the spot early and frequently will give you advance warning of a bad spot. You will know, right away, which direction to fly the canopy. You might even decide to leave a touch early, to start getting safe separation sooner, and therefore permit a little higher opening too.
F. Improve Your Tracking
You'll get safe separation sooner, if you improve your tracking. Then you can deploy your canopy higher and avoid problems with bad spots. This will help you avoid the off-airport landing. You can also get more separation, which will reduce chances of a collision during opening.
1. How much separation is necessary?
The higher the wing loading on the load, the more separation is required. Most people are way too comfortable with way too little separation! You should be able to have an off-heading opening facing directly towards another jumper and still have enough separation to allow for a rear riser turn to avoid a collision. Blaming off-heading openings for canopy collisions is a major cop-out.
2. To Improve your tracking, first improve your attitude: be dissatisfied!
You must be dissatisfied with your present tracking, or you will have no real incentive to improve. Satisfaction with your tracking is a trap and an ego protection device. This ego protection device helps you make your bad excuses for poor tracking more believable. One bad excuse is, "That jerk tracked right over my head when I was ready to pull." Really? Or did you track too steeply and not see where you were going? Be dissatisfied and you'll get constant improvement.
3. With your attitude changed, now experiment with technique.
Many people have not really experimented with body positions for tracking, so you often see poor tracking. I suggest that you occasionally devote an entire skydive just to tracking. You'll have plenty of time to experiment. Make sure you track away from the line of flight, to avoid conflicts with other jumpers.
4. Avoid these common errors:
Arching. This is OK for a beginner, but it causes a steep track. De-arching makes the track flatter. Try bending a little at the waist.
Knees and ankles bent. This slows the track, making it mushy and steep. Straight knees and pointed toes are better, and they should push down onto the relative wind.
Arms up, streamlined with relative wind. This causes a steeper track also. The arms should be pressing down onto relative wind to make the track flatter.
Legs and arms too close together. This does not help the speed much, and usually causes difficulty avoiding a rolling motion side to side. A slightly spread position, with feet almost shoulder width, and hands 6" 12" from torso is better because it aids in stability and makes it easier to deflect more relative wind. 5. When you leave a formation and track up and away, rather than down and away, you're starting to get the hang of it!
On most jumps the fall rate is fast while doing RW, and the body is arched. Since the track should be de-arched and flat, a good track may actually have a lower descent rate than the formation!
III. Conclusions
I have not covered reducing the risks of normal landings and swoop landings because that will be addressed in a different seminar. As you can see, I believe that most of the canopy survival skills are a combination of improving skills and developing better judgment. Because of my emphasis on improvements, there can be no end to this process, and no real conclusion. I do not wish to fall into the too common trap of thinking that I've completed my learning process and I'm safe from harm. I've seen that this is a deadly trap. That is why I would like to encourage you all to share your ideas on the subject with me. I hope I have presented to you some thought provoking ideas and concepts that you can use to help you reduce the risk of accidents at your DZ.
Essay on Exit Order
From an aircraft operations standpoint, as a general rule whichever group will have the slowest climb out should leave first. On a calm day the aircraft on jump run covers about 175 feet per second, or one mile in 30 seconds. Assuming the practical distance that a square canopy open at 2,000 feet can cover is at most about one mile, that means that the first people out would just barely make the landing area from one mile short, while the last would be able to make it back from one mile long. In other words, all jumpers have to be out in a two mile long jump run or some will land out, or a second pass will be required. In time terms, on a calm day no more than 60 seconds can elapse from when the first jumpers leave the airplane to when the last jumper exits. At busy events with several aircraft flying, second passes are not an option.
Let's take a sample jump run, where a large group will take up to 20 seconds to climb out, a 4-way 12 to 15, 2-ways six to eight, solos five, and AFF students about 12 to 15. Our load has an 8-way, two 4-ways, two 2-ways, a solo, and one AFF. That adds up to between 70 and 80 seconds from green light to last out. But it is possible to make it all on one jump run if the eight way gets out first, because the pilot figures at least 15 to 20 seconds for the first climb out. That brings us back to 60 seconds from first out to last out, and one pass. Needless to say, we don't want to do an extra pass because 2-ways want to leave before 8-ways.
(If the 2-ways get out first, the pilot can only count on a five to ten second climb out. He has to put the light on 1/3 to 1/2 mile closer to the dz than he would for the slow climb out.)
That's the timing reason why small groups shouldn't leave first. Now lets talk about separation from other jumpers. First of all, anyone who counts on vertical separation for safety is out of touch with reality. I see people in freefall at 1,500 feet and lower routinely, so just because someone plans to open at 2,500 doesn't mean you should bet your life on it. Everyone needs to open in their own column of air. Horizontal separation is the only guarantee of security. The only real reasons - and they are good ones - why students and tandems get out last are that a student is more likely to balk or ride down, and that canopies opening high can get back from a longer spot. I repeat, horizontal separation is the only guarantee of safety. Vertical separation is a nice idea but cannot be counted on since a minor loss of awareness or a long snivel will eliminate it instantly.
Now, a quick digression about fall rates. Follow these categories out or time their videos if you don't believe me. Light freestylists doing routine freestyle do not fall significantly faster than a fast falling four way. Freeflyers fall about 30% faster than normal. Small skyboards fall fairly fast, if the rider is standing, but big ones fall very slow - slower than most RW, usually about the same speed as tandems. Because of their exits, they must leave first, and because of their complex emergency procedures, they must pull high. Leaving first and pulling high defies conventional wisdom, yet not once have we had a problem with slow falling skysurfers getting out first and pulling at 3,500. In fact, as long as the first person pulls higher than the break off altitude of the following group, they are a contribution to safety, not a detriment, provided adequate time was left between groups at the exit.
We do have a recurring problem maintaining safe separation when the freeflyers get out first. Typically a freefly pair will have a forty five second freefall and open at 2,500 to 3,000 feet. Let's imagine that they are followed by an RW group that has a 10 second climb out. Now, let's say you are a freeflyer jumping a Stiletto. A Stiletto (assuming a 30 mph forward speed, which I can document is a reliable figure) covers about 45 feet per second on a calm day. If you open 30 seconds (shorter freefall plus exit separation time) before the RW group leaving after you and turn directly towards the dz (which you will, since otherwise you can't make it back from getting out first unless you cheat on the climb out, spot for yourself, and force the pilot to go around, which REALLY pisses us off) in that 30 seconds you will cover over 1,300 horizontal feet. This would put you about 400 feet from the center of a group leaving the plane ten seconds after you. In theory, that would just barely be enough, except that a good tracker can do about 70 feet per second, so if they track towards you for six seconds they are right on top of you. Furthermore, a modern canopy descends about 800 feet in 30 seconds (also documented) so if one of you pulls at 3,000 to get back from a short spot, for camera effect, or whatever - by the time you are at 2,000 you are well into the danger zone of the group that followed you.
So far, the big sky theory has taken care of us most of the time but I have heard of a couple close calls and more than once found myself directly over the freeflyers if they leave first. Having seen the consequences of freefaller/canopy collision more than once, I want to minimize the possibilities. And they go way up as soon as we add wind to the exercise. Here's why. In a 30 mile per hour breeze, the plane only covers 130 feet per second, instead of 175. In ten seconds of exit separation, the airplane only covers 1,300 horizontal feet instead of 1,750. Worse still, the RW group is in freefall for a longer time, and consequently gets blown further. Let's say the freeflyer is in freefall for 45 seconds, and the RW for 70. In 45 seconds you get blown nearly 2,000 horizontal feet. The RW blows just over 3,000. That leaves only 300 feet of horizontal separation without taking tracking or canopy movement into account! Make the winds 50 miles per hour, and the RW group drifts over 1,800 horizontal feet further than the freeflyers! Meanwhile, in ten seconds the plane only covers 1,100 feet. A 20 second exit separation will still have the RW group opening 400 feet from the freeflyers, not counting canopy movement or tracking!
Having opened right over freeflyers before, and having just heard from several expert skydivers who narrowly missed freeflyers, and having watched RW groups blow over freeflyers on windy days, I think we have a problem. You might say, make sure the groups leave longer between exits. Well, we do tell them, but if they wait 20 seconds instead of ten, that still doesn't solve the problem because Freeflyers still fly under them under canopy. So for fast fallers your only choice if you want to get out first is to always fly perpendicular to the line of flight for 30 seconds before turning towards the dz. While I am confident most of you are aware enough to do this, it brings us back to the original time on jump run problem. Basically, Skydive Arizona isn't willing to do a lot of second passes just so freeflyers can get out first.
Getting out last except for students solves virtually every problem. You control the horizontal separation, so you can ensure you won't be overtaking anyone in freefall. The windier it gets, the safer you are because you get extra separation by having slower fallers blow away from you. Students take long climb outs and pull real high, so no problem there: just get open and fly off the wind line for a few seconds to be clear of them in the unlikely event that they are in freefall at 2,500 feet.
As for the argument that the canopy separation is necessary in the landing area, I don't buy it. Opening over the top instead of short, you can spiral down to make sure you get on the turn around loads. As for congestion at the landing area, no one else on the loads seem to have any problem, although you may not always get to land right by the fence.
Please give this some thought. Unless one of you gives me an extremely convincing reason why you need to leave first, such as a safe spot for the skyball, I will make it standard policy that exit order will always be
1) skysurfers
2) freefall groups, largest to smallest, regardless of fall rate
(Note (Skr): I believe this is a typo since the real rule is: )
(2a - relative work groups, largest to smallest and then )
(2b - fast fall groups, largest to smallest and then )
(3 - AFF and tandems )
3) AFF and tandems, plus any other very high openings. The main reason for high openings leaving last is not separation, it's that they can make it back from a long spot!
Static, Dynamic and Accelerated Stalls
Before discussing static and dynamic stalls we should first review some terms involving stability. Static stability refers to how something behaves in a steady state. A parachutist suspended under a normally functioning canopy would usually be said to have positive static stability. That is to say that when not changing the position of the toggles or risers, things like airspeed and heading will not change very much from one moment to the next.
Dynamic stability refers to what happens after something has been disturbed from its static state. Once a parachutist changes the position of the toggles or risers, dynamic stability comes into play as the body swings under the canopy.
A static stall refers to what airplane pilots would call a slow deceleration, approach to landing or simply a normal stall. Basically, at an altitude from which it will be safe to recover from the stall, slowly increase the angle of attack and let airspeed bleed off. Keep increasing the angle of attack, gently, until the stall happens.
Under a parachute, this is fairly simple. Slowly pull the toggles down and wait. Do not pull down the toggle so quickly that you swing forward from your normal position under canopy. Hold the toggles all the way down and wait. You should notice the sound of the airspeed decreasing, perhaps a slight rocking in the saddle and then perhaps a noticeable increase in descent rate.
This is a basic stall. For all intents and purposes it is the most genteel stall your canopy will demonstrate.
Recover from the stall by decreasing the angle of attack -- let the toggles up and resume flight.
The dynamic stall is different because of the suspended weight swinging under the canopy.
Again at an altitude from which it will be safe to recover, begin the maneuver from full flight -- toggles all the way up. This time instead of slowly pulling the toggles down, pull them down as quickly and as far as you can and hold them there.
A few different things are happening this time around.
Because your airspeed initially hasn't changed all that much, but you've increased the angle of attack dramatically, the wing is now creating a lot more lift. A function of creating lift however is also the creation of drag. Your canopy as a result will not only go up but also slow down. Your body on the other hand is following Newton's first law of motion and will continue at its current speed and direction. Unfortunately this also asymmetrically loads the front and rear risers, which continues to further increase the wing's angle of attack.
It's a vicious little circle there for a moment or two as increasing the angle of attack slows the canopy more and more. As your body swings farther and farther forward, rapidly, the wing exceeds the critical angle of attack and it stalls.
Your body may have been thrown quite a bit forward of the leading edge of the wing and even slightly upwards of your normal place under the canopy. As a result, your body may feel a much more definite falling or even backward motion than it did during the static stall.
Stalls can happen at any airspeed and at any attitude. All that is required is for the wing to exceed the critical angle of attack.
Up to this point in this discussion, we've been looking at stalls in a fairly normal manner. If you didn't know better you may have thought that the stall had something to do with the speed of the wing or its attitude in relationship with the horizon.
That's normal. Many people make this mistake. After all, we've demonstrated the stalls from a slow deceleration and with a fairly normal relationship to the horizon, earth and sky. That's about where most discussions on the subject begin and end. So, some people might make the mistake of thinking that a stall can only happen if you're flying too slow or if the leading edge of the wing is pointed toward the sky.
Unfortunately, this is just dead wrong.
To make matters worse, some maneuvers that you may perform, turns for example, create G force. Basically, your body wants to continue in a straight line but is getting pulled in another direction by lift. As the bank angle increases, so does the G force. In an airplane, maintaining altitude during a turn, the G force increases at a rate equal to one divided by the cosine of the bank angle. So, at a bank angle of 60 degrees the G force will be 2.
You might not get exactly 2 Gs under a parachute turning with a 60 degree bank though since generally you're not maintaining the altitude and the equation becomes quite a bit more complicated taking into account your descent rate, but in most cases it will definitely be greater than 1.
So what does this have to do with stalls?
As the G force increases so does the amount of lift required to offset it. With the same angle of attack, the airspeed at which the stall occurs will be increased by the square root of the G force. Airplane pilots would call this an accelerated stall.
Let's say you're pulling a sustained 2 Gs pulling out of a steep swoop, your canopy will have an accelerated stall at 1.414 times its static stall speed.
The really insidious part of this is when a person is snapping the toggles down to pull out of a too steep and too low swoop, the dynamic stall comes into play. The body continues in a straight line, increasing the angle of attack and aggravating the stall with really bad results.
It's my opinion that this could be the primary factor in some botched hook turn landings.
Paul Quade is a Certified Flight Instructor and the camera flyer for the Open Class 4-way team, Perris Lightwave.