Emergency Parachute Advice - British Hang Gliding and Paragliding
Contents
1. 1 Measure from the peripheral hem in the centre of a gore up to the very apex of the parachute including the lines This gives the y dimension 2 Measure the width of the gore at the peripheral hem and halve this figure This gives the x dimension 3 Multiply x by y to give the surface area of the individual gore 4 Multiply the result by the number of gores to get the total surface area of the parachute Figure 7 2 Measuring the surface area of a gore x y 46 Section 2 Know Your Equipment Buying second hand There is nothing intrinsically wrong with buying a second hand parachute but you are strongly advised to have it inspected by a BHPA licensed Parachute Systems Checker and Packer Many parachutes sold to hang glider pilots in the 1990s were far too small and could produce fearsome descent rates if ever used at typical hang glider payloads assuming the opening shock did not burst them or break the pilot s harness These should be avoided The licensed packer will check that the parachute is the right size for you has been well looked after is not too old ten years should be considered as the total life of a canopy those without dates of manufacture the manufacturer s name and serial numbers should be avoided and that it is in good serviceable condition Pilot Handbook Handbook 10 7 08 02 22 Page 46 Estimating descent rates where no data is available The graph below can be used to indicate t2. flying If you do find yourself under your emergency parachute and needing to disable a re inflated paraglider you must avoid any asymmetric action which could result in a free wing tip thrashing around uncontrollably Pulling both C risers to create a C line stall has been recommended by European test pilots and may give additional drag further slowing your descent Steerable gliding emergency parachutes Any steerable gliding emergency parachute will have twin risers or possibly four risers As with most parachute design alternatives the steerable emergency parachute concept has a trade off The main reason for having a steerable emergency parachute is so you can steer yourself away from any danger during the descent The disadvantages are Because these parachutes rely on forward glide for them to create lift they require the paraglider to be disabled or released otherwise it will re inflate They tend to be complicated to re pack with more chance of difficulties when opening If you do not have the space to manoeuvre for a landing into wind an uncontrolled landing is likely to be downwind at wind speed plus glide speed Because of the hang gliding requirement for a long single bridle a steerable emergency parachute is not an option for hang glider pilots 54 Section 2 Know Your Equipment Pilot Handbook Handbook 10 7 08 02 28 Page 54 Paraswivels Some hang glider emergency parachutes a
3. and head tucked in Try to use your legs as shock absorbers by allowing them to flex as you impact Allow your body to roll in the direction of the impact After you impact disconnect from the glider immediately getting injured by being dragged across the countryside after a successful emergency parachute descent would be a shame Do whatever you need to do to get away from the glider and parachute even if it means cutting the bridle or cutting your harness use your hook knife Deflate 53 Chapter 7 Safety equipment Pilot Handbook Handbook 10 7 08 02 28 Page 53 the parachute by grabbing the hem at one side and taking it forward into the wind Radio your friends to let them know your position and condition You should also contact the local police who may be launching a full scale search if a member of the public has seen your descent and reported it Preventing paraglider re inflation With paraglider emergency parachute systems it is possible for the paraglider to re inflate after the emergency parachute has been deployed and then for the two to fight during the descent sometimes with disastrous results Various methods of disabling your paraglider to prevent this happening have been suggested but the most important point here is that this problem is far less likely to occur if your parachute is the correct size for you The lower your rate of descent under parachute the less likely your paraglider will want to continue
4. that may easily be confused with the parachute deployment handle in an emergency Be sure to look for the correct handle so you don t waste precious time tugging on the wrong strap many parachutists have died through pulling a strap instead of the correct handle 2 Reach and grab the handle securely If your right hand is not available use your left 3 Get the parachute out Some container systems require you to pull the handle in a certain direction to release the curved pins safety locks before you can extract your parachute Some Velcro configurations require you to peel the opening flap downward to extract the parachute It may even be that you need to use both hands to get the parachute out Make sure that you know your equipment 4 Look for clear air and throw the parachute out towards it Throw hard If it is possible throw the parachute towards the sky or upwards and out You can throw better if you grab the whole parachute deployment bag using both hands 52 Section 2 Know Your Equipment Pilot Handbook Handbook 10 7 08 02 28 Page 52 Your riser s should come to full extension followed by your lines and canopy If you get a good throw away from you your system will open with less loss of height If you drop your emergency parachute below you you risk entanglement You will also fall a greater distance before the parachute inflates and takes your body weight You may want to avoid throwing the pa
5. Chapter 7 Safety equipment Emergency parachutes An emergency parachute gives you a second chance perhaps a final chance when some catastrophe occurs This section details the important points about buying installing maintaining and using a parachute Hopefully this will increase the chances of the emergency parachute system working successfully if it is ever needed The basic parachute system comprises the canopy and its lines its bridle and the attachment to the harness The system is completed by the deployment bag which holds the packed canopy and lines all stowed in a container which is fitted securely to the pilot s harness The early emergency parachutes produced for hang gliding used round or conical shaped canopies Since the late 1980s virtually all emergency parachutes produced for hang gliding and paragliding are of the pulled down apex design or variations on it A central line holds the middle of the open canopy more or less level with the skirt so that air pressure forces the skirt out and the canopy presents the maximum drag area for the smallest amount of material Such designs are also very rapid opening The downside of these types is that some designs can be very unstable and can produce massive opening shocks both of these can be catastrophic so it is important that you buy a properly independently tested and approved product 44 Figure 7 1 Conical and pulled apex emergency parachutes conical pu
6. confident that you have done a good job why not invest in your future by having an independent 49 Chapter 7 Safety equipment Pilot Handbook Handbook 10 7 08 02 23 Page 49 pair of eyes give it a check over Pilots of all abilities have been responsible for the many packing and installation errors discovered over the years Maintenance and repacking Ideally every pilot should learn how to repack his or her own parachute and so become completely familiar with the system You can learn how to do this at a parachute repacking evening organised by your local club make sure that a BHPA licensed packer will be supervising the evening Alternatively take your equipment to a BHPA licensed packer and get the packer to show you how to repack it If you really don t want to understand your emergency system simply get the packer to do a full inspection and repack Repacking should be carried out at the intervals recommended in the parachute s user manual In the absence of such recommendations check and repack your parachute every six months If it has become damp it should be aired immediately and repacked when completely dry Repacking provides an opportunity for a close examination of the entire parachute system for general viability and wear and tear It also allows replacement of the rubber bands which perish with new bands of exactly the correct specification By fitting a parachute your chances of surviving an in flight cata
7. es can be extremely fast when a canopy is spinning out of control Don t leave deployment to the last minute If in doubt throw it out 51 Chapter 7 Safety equipment Pilot Handbook Handbook 10 7 08 02 28 Page 51 Cumulonimbus Do not deploy your parachute as a method of escaping from a cumulo nimbus not that you should ever allow yourself to get anywhere near one You will in all probability be swept up into the thundercloud while dangling powerlessly underneath your parachute In such an emergency situation hang glider pilots are probably best advised to try to fly away from the danger while a paraglider pilot s best option is probably to use the spiral dive rapid descent technique This will give a much higher descent rate than a parachute perhaps 15m s 50ft s Of course if you have suffered catastrophic structural failure in the cloud your outlook is rather bleaker you can throw the parachute and risk being swept up or delay the throw and risk your parachute and or harness being shredded by the opening shock Whilst the latest CEN certified parachutes will survive an opening after a very few seconds of free fall most will not And few if any current paraglider and hang glider harnesses are designed to take free fall parachuting shock loads So keep clear of cu nimbs Deploying your parachute 1 LOOK for the deployment bag handle Harnesses especially paraglider harnesses can have a number of adjustment straps
8. he likely descent rate of a typical PDA canopy given your total weight in flight and the canopy area Check that your parachute area is measured using the BHPA method 47 Chapter 7 Safety equipment This graph is based on a Cd Coefficient of drag of 1 2 typical of many simple pulled down apex designs although the actual Cd of a particular canopy will depend on a number of factors including canopy shape fabric permeability line lengths and drive Drive means that the PDA canopy glides usually contrary to the designer s intent and expectation and so creates lift which helps reduce the descent rate the downside is that your ground impact energy may be increased because of the lateral velocity which may be significant The real descent rate is further complicated by stability Live drop tests have shown that there can be a huge disparity in the way parachutes descend whilst some are stable many oscillate or cone a swirling sycamore like action which can greatly affect the descent rate So this graph can only provide a ball park indication Figure 7 3 Graph of canopy area against load for typical pulled down apex parachutes 135 130 125 120 115 110 105 100 95 90 85 80 75 70 15 20 25 30 35 40 45 50 55 60 65 PDA canopy area m2 load kg 5 5m s descent rate BHPA recommendation 7 5m s descent rate BHPA recommended absolute maximum Pi
9. lled apex Pilot Handbook Handbook 10 7 08 02 22 Page 44 Choosing a parachute Buying a parachute that is clearly marked as conforming to the CEN standard EN12491 is strongly recommended Such parachutes will have passed rigorous speed of opening tests descent rate tests max 5 5m s stability tests and strength tests In the strength test the manufacturer has the choice of two test speeds and the successfully certified parachutes therefore carry on the certification label the warning not suitable for speeds in excess of 32m s 115km h OR not suitable for speeds in excess of 49m s 176km h Other than checking the certification label and deciding whether you will be happy with the lower speed certification or whether you want the added strength of the higher speed tested alternatives the final very important thing you need to do is check that it is available in a size suitable for your total weight in flight this figure includes the weight of your glider If you buy a parachute not certified to EN12491 then the earlier DHV and AFNOR standards give some measure of quality assurance but you must be careful to ensure that the parachute you select will give an acceptable descent rate at your total weight in flight Look for one with documented rates of descent at different loads and choose one that will give a descent rate of less than 7 5m sec ideally around 5 5m sec at your total weight in flight Descent rates equivale
10. lot Handbook Handbook 10 7 08 02 22 Page 47 The graph should not be used when actual data is available nor for anything other than conventional non slotted non steerable PDA canopy types User manual Ensure you receive a user manual with your parachute this should contain instructions for installing it using it and re packing it as well as data on performance size and recommended load Make sure that the parachute has the correct bridle for your glider type Hang glider parachutes require a six metre bridle to keep the parachute clear of the wreckage Single riser paraglider parachutes require a short bridle with an additional Y bridle to connect it to the two harness attachment points Multi riser paraglider parachutes connect the appropriate risers directly to the left and right harness attachment points The complete system Having the perfect parachute is not much use if it won t fit in your harness or if you can t get it out of your harness when you need to or if the connections to your harness are not strong enough Emergency parachutes must be regarded as part of a complete system For this reason you are strongly advised to buy a system from a BHPA licensed packer who will have the knowledge required to sort out the whole package rather than just selling you an expensive component which may actually be of little or no use to you Installing Always unpack and inspect a parachute before fitting it to y
11. n only be measured by expensive controlled testing of transmitted g loads and other parameters so you should place your trust in the CE standard and should only consider buying a helmet that conforms and is marked accordingly The helmet s function We wear helmets to try to prevent head injury especially brain damage The major cause of brain injury in an accident is through acceleration or deceleration of the brain Think of the brain as a jelly in a jar if a person falls over and bangs their head on a kerbstone then the head is 55 Chapter 7 Safety equipment Pilot Handbook Handbook 10 7 08 02 28 Page 55
12. nt fall height As the expected descent rate increases so does the likelihood of injury and its severity A descent rate of approximately 5 5m s 18ft s is recommended as this keeps the likeli hood of injury low while keeping all the other design factors parachute bulk weight manageable Slightly higher descent rates are acceptable but a descent rate of 7 5m s 24 5ft s should be regarded as being the maximum limit any existing parachute system that will at your all up weight give you a sea level descent rate greater than 7 5m s should be replaced It is sometimes easier to visualise vertical descent rates by equating them to stepping off a wall of a certain height 5 5m s 18ft s or 12 3mph is your velocity when you hit the ground after stepping off a wall 1 5m 5ft high A descent rate of 7 5m s is equivalent to a drop of 2 5m 8 2ft When you have imagined falling from this height onto your feet and doing a PLF try imagining falling from this height onto your back or your side or your head You should also bear in mind that in an actual emergency factors such as lift sink altitude a semi inflated paraglider or a damaged hang glider may all conspire to increase or decrease your descent rate 45 Chapter 7 Safety equipment Pilot Handbook Handbook 10 7 08 02 22 Page 45 Checking parachute area There are many ways of measuring parachutes To avoid confusion BHPA licensed packers all take the following simple steps
13. our harness it is not unusual to find faults in brand new equipment so check carefully Be aware that many parachutes are shipped packed for transit and look ready for use but are not The parachute s outer container must be mounted in a suitable place on the harness although in many cases it is built into the harness It may be on the front or on either side with paraglider harnesses it could also be on the back or even under the seat All of these positions have advantages and disadvantages Does the pack get in the way during take off flight or landing Does the pack location involve extra connections when putting the harness on for flight which might be forgotten 48 Section 2 Know Your Equipment Pilot Handbook Handbook 10 7 08 02 22 Page 48 Is the mounting secure so that the deployment bag can be extracted easily Can you see the handle Can you easily reach the handle with either hand If you can only reach it with one hand you have only half the chance of a successful deployment Is the handle likely to get accidentally caught and cause inadvertent deployment Make sure that the parachute fits properly in the harness quite a few harnesses have been manufactured with parachute containers which are far too small and you may need to have such a container enlarged so that you can fit a parachute of suitable size Make sure your emergency parachute riser is correctly attached to
14. rachute down between your legs Hang glider pilots may wish to avoid throwing the parachute through the control frame as this could result in the glider inverting which usually limits the pilot s ability to adopt a sensible landing position 5 Look to make sure your parachute has opened The deployment bag should release and the canopy start to deploy as soon as the bridle is at full stretch If it does not try yanking the bridle several times very hard Hopefully the parachute will inflate and the bridle will be yanked out of your hand If this does not release the deployment bag pull the parachute back in hand over hand Throw the parachute again If the deployment bag has released but your canopy has not yet inflated yank vigorously on the bridle This will help to spread the suspension lines and open an air channel If you are pulling on a parachute bridle never wrap the line around your hand and let it go immediately the parachute starts inflating The parachute will inflate with tremendous energy 6 Prepare for impact Paraglider pilots should assume the PLF position see Keep practising your PLFs on page 11 Hang glider pilots should unzip their harness and climb into the control frame keeping their weight distributed towards both corners of the base bar If this is not possible concentrate on getting into a foot down head up position with your feet together and your knees slightly bent Keep your arms
15. re supplied with a swivel fitted into the bridle It is not unusual for a broken hang glider to spin like a sycamore seed as it descends under an emergency parachute and the swivel is intended to prevent the parachute suspension lines being twisted together if this happens Such twisting could ultimately result in the canopy mouth being closed with obvious dangers Paraswivels are more common in countries where high altitude flights are made regularly and where a parachute descent is likely to take tens of minutes rather than the tens of seconds likely in the UK Summary An emergency parachute should be part of your flying equipment Choose one that will give you a true non gliding descent rate of around 5 5m sec never more than 7 5m sec at your total weight in flight including the weight of your glider Preferably choose a certified emergency parachute Make sure that it is correctly connected to your harness and correctly installed so that it can be deployed when you want and won t deploy unintentionally Maintain it properly which includes having it repacked regularly Make sure you know how to use it and use it when you need to Helmets Over the past forty years there has been a great deal of research into helmet technology and the recent European CE standard Helmets for Airborne Sports EN 966 has benefited enormously from this accumulated knowledge A helmet s effectiveness ca
16. strophe have been increased but you are now exposed to the danger of experienc ing an in flight emergency in the form of an unintentional deployment Approximately one in three deployments are unintentional this is mainly because pilots fail to check and maintain their equip ment adequately Pre ight checks As part of your pre flight actions Check that your parachute container is properly closed and that any closure pins are secure and free to release Check that the deployment handle is accessible Check that no slack loops of riser have slipped out of your parachute container Check that you have easy access to your hook knife Be particularly careful with Velcro closure systems As Velcro gets old it can get clogged It can also lock together over time so a pull that is easy 50 Section 2 Know Your Equipment Pilot Handbook Handbook 10 7 08 02 23 Page 50 when the parachute is first assembled can become almost impossible after six months Pin closures are generally much better but still need constant vigilance Don t be the next pilot to end up dangling beneath your chute when you least expect it Using your emergency parachute Practising Once you ve got your system sorted out the next job is to learn how to use it Your emergency parachute s user manual should advise you how to deploy for real and how to practise on the ground Some clubs and schools have built suspended sys
17. tems that you can strap into for practising deployment Make full use of any simulator to which you have access practise looking grabbing and activating your parachute handle with first your right hand and then your left hand Make sure you know whether the container requires you to pull in a certain direction The slowest elements in deploying the emergency parachute are invariably making the decision getting the parachute out of the harness and thrown Time and effort spent in practising these actions and improving these parts of the system will pay the biggest dividends When to deploy With situations such as a structural failure of your hang glider or paraglider the appropriate action is clear deploy the parachute With paragliders there is a range of less clear situations where control of the canopy has been lost but may be regained The decision whether or not to deploy will depend on the height that will be lost during your attempts at recovery and your initial proximity to the ground Several pilots have been killed and many injured impacting the ground while still trying to recover control of their paragliders when their parachutes would almost certainly have saved them The crucial point is that any efforts to regain control of the paraglider must be secondary to the key concern of monitoring your height Recovering from a complete mess is very satisfying if you have plenty of height to play with however descent rat
18. your harness Modern certified paraglider harnesses are supplied with tested loops on the shoulders you must attach the parachute to both of these so the load is spread equally With hang glider harnesses the emergency parachute is connected to the main harness suspension point using a separate steel maillon connector The bridle s must be carefully routed to ensure that no twists will occur as your emergency parachute deploys and that the bridle s will not get tangled with your paraglider risers hang glider hang strap or with you the pilot you do not want the bridle around your neck See the section on connectors in Chapter 8 Check the whole system when it is put together with you suspended in the harness in full flying kit Is the strop on the deployment handle strong enough to withstand the force of the pull Is the strop on the deployment handle the right length It must pull the outer cover closure pins completely clear before starting to drag the deployment bag out If not it will be impossible to extract the parachute no matter how hard you pull Can you easily deploy with either hand If you are not 100 confident that you fully understand the whole list of items that must be matched and checked to create an effective emergency parachute system then get a BHPA licensed packer to install it properly for you and explain the system to you In fact even if you have put the system together yourself and feel
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