I have altered this article to include the current thinking on back protection. Modern canopy certification includes more appropriate information on the type of harness suitable for a particular glider. The basic types are still as below but Sup-Air have developed a specific version of the 'triangular' or 'semi cross' brace which they have called ABS. My current glider has ABS specified as the optimum harness type and flies very much better with ABS than other types!

Any serious skier will tell you that it is useless having good skis without a good pair of ski boots. In the same way as ski boots are the interface between skier and skis the harness is the interface between pilot and canopy. The handling of a canopy can be greatly affected by the type and adjustment of the harness which should be carefully selected to suit both canopy and pilot.

In this harness any roll movement of the canopy is transmitted directly to the pilot and conversely it is easy for the pilot to apply weight shift to help turning. This 'sensitivity' can help the pilot locate light lift, but can also give a rough ride in turbulence. The pilot will also need to ensure that his weight is kept on the open side of the canopy during asymmetric deflations. The coupling of rolling action between canopy and pilot may be reduced by tightening the chest strap to bring the suspension points closer together but this can lead to other problems which we will examine later.

Another way of reducing roll coupling between canopy and pilot is to introduce cross bracing. This makes things feel very solid and will keep the pilot well upright during an asymmetric deflation. The pilot does, however, lose some sensitivity and there is a danger that the canopy will feel safer than it really is. Some systems have the facility of adjusting the length of the cross braces to adjust the 'feel'. These may be adjusted so that the seat is allowed to roll a little before the cross bracing tightens. This allows good sensitivity in light conditions but will still limit the amount the pilot is rolled in turbulence or during asymmetric closures. There are now Gutesiegel and Acpuls standards for cross bracing and some canopies will only conform to their ratings if flown with suitable harnesses.

This behaves similarly to a cross braced harness with slightly loosened braces allowing a certain amount of roll before the bracing tightens. Again this allows good sensitivity, but limits the amount of roll coupling between pilot and canopy. The geometry allows a tidier harness construction than the cross brace needing only one chest buckle and enabling the suspension points to be kept quite low.

This harness was developed by Advance to match their canopies. The leg straps are configured in such a way that if the pilot sits back the leg straps slacken allowing the pilot to roll easily. If, however, the pilot tips the seat forwards the leg straps tighten and act rather like cross bracing. The design thus allows the pilot to control the amount of roll coupling in flight. A limitation of this sytem is that as the pilot lifts his legs to operate the speedbar the cross bracing action is reduced.

In general the higher the suspension points are the more upright the pilot is forced to sit and the farther the pilot will have to reach when pulling lines for 'big ears'. The use of maillons instead of karabiners may help here by effectively shortening the risers. With lower suspension points weight shifting and ground handling is usually easier and the pilot feels more of the roll movement of the canopy. Cross braced harnesses tend to have higher suspension points simply to accommodate the cross brace system itself.

Adjustment of riser spacing is usually accomplished by adjustment of the chest strap. In general the wider the spacing the more the roll coupling between pilot and canopy. Pulling the suspension points together usually makes the canopy feel more stable in roll, but too close and there is an increased risk of a 'Twist'. Thus for a given canopy there will be an optimum spacing.

On most modern harnesses the pilot's posture can be adjusted from sitting upright to lying almost horizontal. The diagrams show that the upright pilot has a large moment of inertia about the axis of roll (R) and a small moment of inertia about the yaw axis (Y) and vice versa for the fully supine pilot. This means that the upright pilot is less easily rolled by forces on the risers and more easily yawed than the supine pilot.

• In Roll. The upright pilot will get a smoother ride and his inertia will help to keep the canopy level.



• In Yaw. The body of the upright pilot will follow the rotation of the canopy more easily than that of the fully supine pilot and is less likely to suffer a 'Twist'.

An upright pilot is thus more stable than a fully supine pilot and, of course, has a better view.

This occurs if the canopy suddenly spins without the body of the pilot following it. The lines twist together between the pilot and the canopy locking the brake lines. As previously mentioned the likelihood of a twist occurring can be reduced by using an upright pilot posture and relatively wide riser spacing. Pilots who tighten their chest straps in rough conditions may unwittingly be risking a twist.

Paraglider pilots are particularly vulnerable if swung backwards into the terrain and spinal injuries are common.

There is much debate about the optimum type of back protection at present and it seems that an energy absorbing 'soft' protection is to be preferred. This is a complicated issue and the BHPA Pilot Handbook goes into this more thoroughly.

Most modern harnesses have some provision for an emergency parachute. If the emergency parachute cannot be reached easily a front mounted reserve should be used.

In addition to the canopy bag it may be necessary to carry spare clothing and other items. On most harnesses storage pockets are rather limited in size and should be checked for adequacy before purchase.

Remember also that in the event of an accident items stored in these pockets can seriously injure the pilot. A back protector must be used if any hard items are carried behind the spine.

A comfortable pilot will fly better than an uncomfortable one. If possible the pilot should hang in the harness for an hour or so and try any 'in flight' adjustments before purchase. However it does seem that a harness suspended from vertical ropes does not feel the same as it will in flight. If possible a flight test of a harness before purchase is much to be preferred.

As with canopies manufacturers try and restrict the number of sizes of a given type for economic reasons. Pilots who are particularly large or small should not be fobbed off with badly fitting harnesses but seek alternative suppliers if not satisfied.