This article is obviously very dated as the certification system is now much improved and the performance difference between 'beginners' and 'advanced' gliders has closed considerably. However, I believe that much below is still relevant so it has been left unaltered.

The business of changing canopies has many pitfalls. In all probability the first canopy will have been purchased from the school the pilot trained with and the choice will more or less have been made for them. Whatever type your intended new glider is, a few ideas might help reduce the heartache.

Often pilots will purchase an 'intermediate' glider for their first canopy and a 'performance' canopy next. Do not rule out an intermediate glider for your second canopy. For the most part they have sink rates approaching those of 'performance' canopies, lacking only the top speed and glide.

If you decide on a 'performance' glider remember that manufacturers figures are notoriously inaccurate, some would say apocryphal. What about looking at competition results to assess performance instead? Still a problem. Many competition pilots fly oversize gliders with ballast because on the whole, large aircraft are more efficient than small ones and ballast can sometimes be dumped to improve sink rate. Thin lines will give a canopy several extra kilometres per hour and a noticeable improvement in glide. Trimmers and speed bars with extended travel can help too. Finally there is the prototype, anybody's guess!

The best way to find out a particular glider's performance is to use other canopies as benchmarks. I know that if I fly for a prolonged period with another pilot on a glider of similar performance I should be able to get as high as them sometimes, no matter how good they are. If I never get near them I know their glider has a significant advantage. Make sure you are comparing like with like.

There are very few dangerous gliders but there are many pilots who fail to understand the limitations of their aircraft in relation to their own abilities. A particular problem is that of pilots failing to recognise how different one type of glider can be from another. At one time many of us thought that glider designs would converge and canopies would all be very similar. How wrong we were! There can even be significant differences between different sized gliders of the same type.

The search for a certification system which is understandable and meaningful continues and great advances have been made. Remember that the pace of canopy development is still such that any certification system is a little dated by the time it is fully implemented. Be picky with the dealer and make them get you a copy of the homogelation certificate for the glider they intend to sell you. Check with the BHPA office if you are in any doubt, they should be able to get copies.

A canopy with a bad reputation usually has so it for one of two reasons:

Early in its manufacture a pilot with a good reputation has a bad crash on one which puts many pilots off buying it.

Early in its manufacture it obviously has a good performance and produces good competition results. Many inexperienced and overcompetitive pilots start flying it with inevitable results.

These reputations are usually unjustified but a new or 'different' canopy should always be flown with particular care.

Some pilots use ballast to bring a canopy to its optimum loading or steady the glider up a bit in strong winds. I believe that if I am paying a large sum of money I want a glider that will fly at its optimum safety and performance. For me this means my glider should be near the middle of its weight range without ballast and I may choose a different model rather than compromise. Despite this view I have to admit that in my current 'time of life' I can see the potential of using ballast to compensate for unscheduled changes in body weight!

Changing the loading of a canopy may not have the effect you might expect. On our flexible and elastic wings the theoretical relationship between all up weight and performance does not hold as well as it would for more conventional aircraft. Make sure you size your canopy for yourself plus all your kit. It's surprising how much odd bits and pieces can weigh.

The obvious way to find out if a glider is suitable is to fly it but there are still problems here, weather being one of them. If you fly a glider in good conditions you will probably like it and vice-verse. How a glider feels to you will also depend on what glider you are used to. I reckon that to adapt to a high performance glider with a very different feel to one I'm used to may take me twenty hours. Treat an unknown glider like glass!

Having mentioned how different gliders of similar specification can be lets try and get a bit more specific. In the following paragraphs finer differences are probably more relevant to 'performance' gliders than 'intermediates'.

Until recently type certification was based mainly on the canopy's ability to recover from tucks, not how susceptible they were to tucking in the first place. This led to serious anomalies. With similar certifications we could have canopy A, which tucks often but recovers well and canopy B which hardly ever tucks but has bigger problems when it does. Thus, a pilot used to flying canopy A would acquire have plenty of experience of handling tucks and a pilot used to flying canopy B would not. In the case of either pilot having a really bad tuck the pilot of canopy A has a lot of relevant experience whereas the pilot of canopy B does not.

If that all sounds too complicated try asking yourself which of these two 'performance' canopies is safest.

A canopy which tucks fifty times in fifty hours flying whose tucks are easily controllable.

A canopy which tucks five times in fifty hours but whose tucks have a one in five hundred chance of being seriously difficult to handle.

If you can't deal with the consequences of questions like this the answer may be to fly an 'intermediate' glider where we expect few tucks to occur and those that do to come out with little, if any, pilot input.

Nobody makes us take off in rough conditions.

A pilot who has flown a particular glider for some time will become 'tuned' to that glider and will often know by feel when a tuck is likely to occur. An experienced pilot can often use a strategic pump to limit the extent of a tuck or even stop it from occurring at all. Such a pilot changing to a canopy with a different 'feel' may suddenly find tucks occurring apparently without warning and feel very insecure until they have 're-tuned' their reactions to suit the new canopy. This can make test flying very difficult.

In given circumstances gliders may also tuck in different ways depending on their design. On the whole experienced pilots will not worry much about losing the outer part of one wing and 'performance' gliders often have quite 'loose' tips which need to be pumped out of big ears. It may be quite difficult to keep an 'intermediate' glider in big ears.

Gallileo figured out that the longer a pendulum is the more time it takes to swing from one side to the other. If we are used to controlling the swing of a particular canopy without thinking we may need some time to adapt to one with a different period of swing. A canopy whose swing is difficult to control will be more prone to tucking and may be difficult to 'scratch' lift close to the hill. Note that line length is only one of a number of factors which influence the period of swing of a canopy.

Different gliders respond differently to a given amount of brake. Typically one glider may require a large force applied but only a small amount of movement to effect adequate control and another will need a relatively small force applied over a longer travel. For pilots with weedy biceps like me selection of canopies for light brake force is especially important if long flights are to be made. I have recommended some pilots to try canopies which I believe are excellent but would not choose for myself because of their heavy brake force.

Intermediate' gliders will usually tolerate very large brake inputs without stalling or spinning but 'performance' gliders may not.

Different gliders respond differently to weight shift. Harness type and adjustment can affect weight shift response dramatically and this must be borne in mind when test flying. The wrong harness can ruin handling. Moves are being made towards standardising cross bracing systems but care still needs to be taken to ensure good matching of pilot, harness and glider. Ballast can also affect the way a canopy feels by providing a significant mass connected directly to the canopy, i.e. not through the pilots bottom.

If we are careful and are prepared to make do with something less than the latest models there is no doubt that many bargains can be had second hand. We also have the advantage that any problems with a particular model should be well known. The difficulty is in assessing the condition of a canopy and in this it is a great advantage to know the previous owner. The main agents which degrade canopies are dirt, rough ground handling, ultra violet and water. Apart from an obvious thorough examination of the canopy when considering the number of hours flown quoted by the vendor ask yourself the following questions.

In addition to the quoted flying hours how many hours has the canopy lain unpacked in the sun waiting for conditions to improve?

How much heavy ground handling has the canopy had.

Has it been frequently or intentionally been flown in rain or wet conditions? Has it always been dried quickly afterwards?

Has the canopy been flown much in very hot or alpine conditions?

Does the vendor usually make quick clean take-offs or do they spend a long time dragging it around first?

Has the canopy been folded carefully and kept properly?

Thankfully porosity problems are scarcer than they used to be but it is still well worth having a good suck, being careful, of course, to avoid any brown marks! When you're on the hill have a look round and see if you can connect the appearance and feel of peoples canopies with the way they treat them.