Cairngorm Gliding Club
Latest news from the Club
AIRFIELD DIARY for Sunday 20th September
Sunday was a fantastic day for glider pilots! Our members made 9 flights averaging nearly 2 hours each, and virtually everyone exceeded 10,000 feet in altitude. We can't resist sharing our stories and pictures.
Paul Maddocks captured this superb wide angle view of Loch Rannoch from the back seat of Nick Norman's ASH25, also showing Dunalastair Water and the valley leading down towards Tummel Bridge. They were in the region of Schiehallion at around 12,000 feet. Green fields, forests, bare rocks and cloud shadows, just beautiful.
Paul writes: "I got the best seat in the house today, watching the Master romp round 300km at an average speed of 134kph. I hope I learned a few lessons."
The XC Therm forecast. When glider pilots see the whole country covered by these zebra stripes, they tend to get very excited!
The coastline is quite difficult to pick out, but our airfield at Feshiebridge is more or less in the middle of this view. There was very little wave activity over the western isles and in the Aberdeen area, but otherwise the whole country was covered by these eerie ripples.
Nick Norman writes: “I flew an easy 306km task in the ASH25 at an average speed of 134kph starting at Kincraig, then Fearnan on the shores of Loch Tay, then Boat of Garten, then around Ben Nevis and returning to Feshiebridge, taking 2hrs 20min, so back in time for lunch! By the time we were half way from Boat of Garten to Ben Nevis, we already had sufficient height to complete the route and get back to Feshie. Unfortunately the impressive Ben Nevis was completely obscured by cloud, but we rounded it anyway, above cloud.
"Although it was below freezing at our cruising altitudes between FL80 and FL120, we were quite warm from the blazing sun and the greenhouse effect of sitting under the bubble canopy, despite not wearing outdoor clothing. We were also using oxygen cannulas. Quite a lot of time spent cruising along wave bars in level flight at 90 knots indicated airspeed (110mph true airspeed). Strong lift near Kenmore made me slow down to make the most of the lift - 9 knots at 10,000ft and the photo shows we still needed a further 14,620ft of aggregate climb to complete the task."
Craig Chatburn sent this view from the K-21, with a wave trough visible as a gap in the cloud. The wind is blowing from right to left, and the nearest edge of the gap is where the airflow is rising. Cloud is forming (condensing) along this edge. Although the glider has now climbed above most of the cloud, it is still gaining height because the invisible airflow layers are stacked neatly on top of each other.
On the far side of the gap, the airflow is descending from the previous wave (the next coloured stripe in the forecast map). Cloud is evaporating along that edge due to a slight increase in temperature at lower levels.
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Craig also snapped Bill Anderson flying his 'Cirrus' (golf charlie delta) just above the cloud tops.
... and he also saw the "glory" which is a faint circular rainbow around the glider's shadow. The physical explanation of the glory is quite different to that of an ordinary rainbow, and was not fully understood until the 1970s. It is caused by the "complex angular momentum (rotation) of the electromagnetic field of a light wave."
Craig's forward speed is about 46 knots and the Borgelt vario is showing over 500 feet per minute. The compass (centre) shows he is heading about 315 degrees, more or less exactly north-west and therefore directly into wind. We know the wind speed at that height was 40 knots or more, so his actual progress over the ground at this point would have been little more than walking pace.
This photo by Stewart Hills from the club's "Robin" tow plane.
Note how the single propeller blade appears to be fuzzed out sideways because it is moving whilst the pixels in the smartphone camera are gathered in a split second, row by row from top to bottom.
One of our youngest members, Reuben Lowe (17) flew for 2hrs 17min in the single-seat Astir belonging to the Club. He sent this fine view looking into wind at the regular arrangement of wave bars stretching into the far distance. He impressed himself by repeatedly bumping up against a self-imposed height limit of 10,000ft.
So few people are able to enjoy an afternoon appreciating sights like this, being amazed by the free energy in the atmosphere that will easily lift aircraft with no engines to great heights.
We wish there were more people like Reuben who would think seriously about learning to fly with us. We badly need more young members to keep the Club going in future.
AIRFIELD DIARY for Saturday 28th February
Beautiful sunny day, with a light southerly breeze and even a few early spring thermals. Photos by Stewart Hills (Kincraig).
​​​​​The north end of Loch Einich, looking east towards Cairn Gorm. The flat-bottomed cloud layer shows that thermal convection is present, but the clouds are aligned with the mountain slopes leaving blue sky over the river. This is a common pattern, suggesting wave influence is at work here. The leading edges and tops of the clouds also exhibit wave-like curvature. Pilots learn to recognise these clues in their search for lift.
The south end of the loch, as seen from the vicinity of the Sgòr Gaoith viewpoint. We are looking towards Blair Atholl and Glen Tilt in the distance, although the visibility is not very good, and the view would be better if the glider was a bit higher. Sometimes the pilot has to settle for a narrow gap between the mountain tops and the cloud bottoms!
Jordan Thomson, flying his Standard Cirrus glider, looks over his shoulder as Stewart edges in for a close-up. The Cirrus has a 15 metre wingspan and was very successful in competitions during the 1970s and 1980s, although the turned-up wingtips on this one were added much later.
Overhead view of the airfield, with another aerotow launch about to begin. The braided streams of the Feshie river are seen clearly here.
Near the top right corner, notice the dark wooded sector between the river and the south end of the runway. This was actually part of the riverbed about 25 years ago. The trees have grown up in the last couple of decades as the river has shifted its course to the west.
Saturday 7th February
photo by Nick Norman
In recent years, stubborn high pressure centres over Scandinavia have caused a freezing blast nicknamed the Beast from the East, which typically lasts for a week or two. This year, the location of the high has been slightly displaced, giving persistent south-easterly winds and relatively normal temperatures for the time of year. These onshore winds have dumped an incredible amount of rain on the east coast of Scotland during the past few weeks. At the same time, the Scottish west coast, normally mild and wet in the Gulf Stream climate, has been much drier and sunnier than usual. In the Spey valley we are between these two extremes, and conditions have been neither one thing nor the other. Most of the time we just get the dull cloud that has had most of the rain squeezed out of it on the other side of the mountains.
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But the steady SE wind does have occasional benefits for us, because it can create wave gaps in the cloud. Our Club Treasurer Nick Norman sent in this photo from 8,400ft, which shows ​wispy edges to the snowfields extending down the slopes, wispy edges to the wave clouds, and wispy edges to Dave's hair, which look amusingly similar!
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He writes: "I left Aberdeen this morning, where it was raining. It has been raining for all of January (when it wasn’t snowing) and all of February so far. I traversed the Lecht, where the skiers were in thick fog. I descended into the Spey Valley, where it looked pretty grim. I arrived at Feshie at lunchtime to see a glider just landing. How did that happen? Bill Anderson had just flown 50 minutes in the only cloud gap in the whole of Scotland.
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"I could see the gap above Glen Feshie - fairly typical in a SE wind. So Roger kindly launched Dave and myself in the Perkoz, and as we passed Achlean we hit strong lift. The S80 vario was giving us a climb rate of 10.5 knots, which wasn’t bad since the local horizontal component of the wind was only about 12 knots.
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"It’s not often my ears struggle to equalise pressure, popping on the way up, but today was one of those days. Anyway we flew along past Einich, beyond Morlich and topped out at FL100. Unfortunately the oxygen equipment in the glider has had to be sent away to USA for service or repair, so we couldn't go any higher. We declared it was too cold, and warm soup was beckoning in the clubhouse."​
AIRFIELD DIARY for Sunday 18th January
Sunday was a fabulous day for soaring the mountain waves over the Cairngorms. Photos by Paul Myers, who flew for almost 90 minutes in his single seat "Ventus" glider. He reports:
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"The photo of a half frozen Loch Morlich was followed by a climb averaging 12.7 knots (almost 15mph) vertically to 13,000ft. Glories in the cloud tops, a frozen Bear's Paw, and very cold toes!"
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Several other pilots made successful flights, including Nick Norman and Andy Farr who flew in the Perkoz two-seater to Corgarff Castle and back. Seven flights in all, with a total air time of 9hrs 40mins, and we think that everyone managed at least 7,000 feet in the wave (statistics by Andy Farr).
The 'glory' is a circular rainbow formation seen when the sun is directly behind. It indicates the cloud was formed of water droplets that were not frozen into ice crystals. It also means the droplets were very small compared to the size of normal raindrops, which refract sunlight in a completely different way to create an ordinary rainbow.
Also notice the tops of the wave crests are usually very smooth compared to the ragged edges down below.
Descending from a great height towards a landing at the nearby airfield. The Bear's Paw (Uath Lochans) was still completely frozen over on this day.
Stuart Naylor, one of our friends from the Highland Gliding Club near Elgin, sent us this view from the same day. He had only intended to do a short half-hour check flight, but the conditions were so good that he flew 220km (135 miles) across country, right above our heads and as far down as Dalwhinnie before returning to base. You can track his flight graphically from here.
