Winter Soaring



I personally very much enjoy flying from Eyres Field, and think the scenery is second to none!

I hope this article may bring back some pleasant memories to those of you who used to fly at Old Sarum. Winter ‘soaring’ from a flat site.

We all like to soar. It is man against the elements - against gravity - against those hundred and one things that are trying to keep our feet firmly on the ground. If, as I do, you fly from a flat site, you will have experienced the frustration of winter flying. Every now and again when every possible weather criteria is right, i.e. wind strength, wind direction, and enough members turn up on a day when the duty instructor has enough foresight and vision to realise that flying in strong wind conditions can help everybody become better pilots. Pilots who spend the whole of their time only flying in ‘good’ conditions are one day bound to inadvertantly experience very rough conditions. Will they be able to cope?

In clubs that operate from ridge sites, pilots learn right from the word go how to cope with extreme flying conditions, such as curl over, strong wind gusts, extreme wind gradient and all kinds of unusual wind turbulance that pilots who only ever fly from a flat sight cannot even begin to visualize!
So where were we? Oh yes. We are back on our flat site, in the middle of winter, with just enough people to make it viable to fly.
So where do we start looking for the means to extend our flight times from the usual 4 minute up and down dash?
Although, as I do, most of you fly from flat sites, there are bound to be one or two topographical features near enough to your airfield, which given the right wind direction and strength could enable you to perhaps double, or even treble your average flight time. ( all you ridge site pilots out there please bear with me, remember that there are thousands of glider pilots that do not have the ‘luxury’ of a soarable ridge, and have little idea of what ridge soaring is all about).

I will use my old home club site at Old Sarum, Wiltshire (where The Dorset Gliding Club was based until 1992), as an example of how it is possible to find lift even on a relatively flat sight in the middle of winter.
There is a small ‘hill’ rising to about 50-70 ft above the level of the airfield, and running diagonally to it. It is about 800 metres long and running approximately SE to NW.
The steepest face of the ‘hill’ faces NE and is approx. 500 metres from our strip. Given a wind direction of approx. NE and a wind strength of 20 kts plus, it is possible to ‘soar’ this ridge at a height of 500-900 ft, and given the above criteria we ‘Old Sarum’ flat sight pundits have been known to keep a K8 airborne for up to an hour or more!
Of course the length of flight depends on a steady wind strength, as at that height only a short lull in the wind will mean that you will be rapidly back in the circuit.
There are a few of us at our club who made use of our ‘mini-ridge’ and as far as I am aware there were no dangerous incidents. There will always be the occasional instructor at any club who regards the working of lift at a height of less than 600 ft as irresponsible and dangerous, but I believe that used sensibly our ‘mini-ridge’ was a legitimate and safe means of extending your winter flying times. (Being winter, of course means that there are rarely more than 2 or 3 gliders airborne at any one time so the likelyhood of a ‘gaggle’ does not arise.
The pilots at our club who bothered to persevere and ‘fine-hone’ their flying skills on our ‘mini-ridge’ invariably found a great advantage when visiting ridge sights. Because we learnt our ridge flying skills on such infinitisimal amounts of lift, we used to visit ridge sites and often managed to stay up, while the club pundits were scratching their heads and wondering why the hell we had even bothered to rig!!
One other source of lift we could also use in the winter was Old Sarum ‘Castle’ at the Western end of the field. This is not really a castle but an ancient earthworks which rises to about 100 ft above the valley floor. Reasonable lift can be found in a N-N/Westerly wind of 15-25 kts.
Winch launching from the eastern end and pushing into wind the lift at the upwind edge was usually workable down to about 700 ft. The technique is to reduce speed as you fly through the small area of lift, and fly as accurately as possible slowly into wind. As soon as sink is indicated, turn to the left and do a 360 turn back over the ‘castle’ and into the lift again. This can be repeated ‘ad-infinitum’ , and given sufficient wind strength the small height loss in turning should be regained flying back through the area of lift. The secret is accurate flying, with well co-ordinated turns and flying at such a speed that you spend the maximum time in lift and the minimum time in sink.

The location of Old Sarum ‘castle' was such that at say 700ft you could do your last turn as a 180 and join the circuit to the south of the field. (All glider circuits at Old Sarum were done to the south, irrespective of which end we were launching from).
Joining the circuit was straightforward, and there would be no gliders flying our ‘mini ridge’ as this only works with a N/Easterly wind direction.
I have illustrated just a couple of ways in which it is possible to extend your flight times given the right conditions in the winter, and which can also enable you to ‘polish’ your flying skills so that when you do visit a club with a ‘proper’ ridge you should be more able to make the best use of it.
It is a good feeling when you have had an extended flight and the ridge club pundits have not even thought it worth launching because of the weak lift.

Remember also that these areas I have described can also be the best areas for ‘kicking’ off thermal lift in the summer.
So don’t give up flying in the winter months. Your club needs the revenue, and you may just discover that elusive area of lift that can make your flight even more worthwhile.
There are certain areas near Eyres Field that give useable lift in the winter. Talk to the club ‘pundits’ who are always eager to divest themselves of their hard won knowledge.

Think about it! Happy flying,

Colin Weyman.

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