Last Wednesday's blog introduced Keat's "Season of mists and mellow fruitfulness..." which proved apt this morning too. It dawned with some local mist but was forecast to clear to be a lovely autumn day with a light easterly wind. Great for our visitors and trainees and with some gentle thermic activity too, peaking at 1.6 knots; just enough to hold a well handled glider at "zero sink" or at least to slow the rate of descent back to mother earth.
Skysight has a new feature; a Point Windgram, which displays the day's weather in an interesting and digestible format showing wind direction and strength, thermal activity, condensation level, boundary layer, and cloud. A good summary.
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| Skysight's new Point Windgram overview shows how the day might shape up |
As mentioned the wind was forecast from the east but light. So conventional wisdom expected no indications of wave in the forecasts. However, I have noticed an interesting feature in Skysight's predictions of convergence this year. Often we experience wave that the forecasts didn't predict. Brentor pundits attribute this to the "Hydraulic jump" caused by the local topography when the air comes down off the moors into the Mary Tavy valley and then pushes the air upwards towards the airfield. The convergence forecast seems to indicate when this will happen. Skysight describes this chart as showing the "Maximum up/down motion within the Thermal Layer, as created by horizontal wind movement" which is just what we are interested in. Empirical testing is the order of the day so we better go and test it!
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Is this caused by wave or a hydraulic jump? Let's go and find out. (Blue shows sinking air and light green shows air rising at 0.2 knots).
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Some schools had their half term last week, where we welcomed Matthew and younger brother Hugo last Wednesday. However, this week is half term for most of the schools in the local area. So the Duty Instructor, Mike Jardine, girded his loins ready for a welcome onslaught of Juniors wanting to make the best use of the autumn day. Phil Hardwick as the Duty Basic Instructor had three visitors scheduled (two trial flights and a One Day Course) so he would be busy too. We also welcomed Trevor "Treasure" Ashbolt who thoroughly enjoyed his trial flights on Sunday and came back today to make the most of his temporary membership. Welcome Trevor or should that be "Treasure"?
Whist the hangar was being unpacked my thoughts on "Mellow fruitfulness" brought a recollection of the Halloween pumpkin competition held at Cotehele Mill on Monday. It might have been raining and a bit miserable all day but it attracted many half-term visitors eager to cast their votes for the inventive creations on display.
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Pumpkins ripe for the judging at Cotehele Mill
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My musings continued through the morning brief where the weather and RASP predictions aligned with Skysight. Apart from the Okehampton firing range being active there was nothing to be concerned about.
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The competition winner. I think it depicts an Eagle Owl just like our Puchacz!
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A more earthy creation. Perhaps one that DGS pilots associate with?
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My reverie was interrupted by the Duty Instructor giving a lecture to the assembled trainees on Airmanship which went down well. David Baker arrived for his One Day Course and Phil briefed him. Trevor AKA "Treasure" sat in on the brief as it was useful to a newcomer. Then I gave a lecture on the primary effects of the controls which David sat in on too. Then it was time to flying.
Although the winds were very light they were forecast to freshen later from the east so we set up at the west end end. Mike Jardine took Geoff up for a pair of flights to continue his training.
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Gosh! These pre-flight checks require a lot of concentration
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John Osmet took a pair of solo flights in a K-13 to get his eye in at the start of the day whilst Mike Bennett, John Allan, and Peter warmed up the K-8 for him. There were soaring flights from all three pilots, and in particular 22 minutes by Peter, which ensured that it was working perfectly. The Astir CS77 was also in use today by Hugh and with Sean (11 minutes) and John Allan (30 minutes) managing to soar.
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Total cloud cover summed up the day but belied the very pleasant and benign conditions
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Phil started David Baker's One Day Course with a pair of introductory flights.
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The One Day Course starts with David Baker and Phil
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Sean laughing at his own jokes before enjoying a pair of short soaring flights
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Then Phil took our first trial flight visitor aloft. William Stevens was staying with his grandfather during half term. Although his grandfather lives very close to the airfield Steven hails from Barnet, North London. A quick peruse of the British Gliding Associations "club finder" page reveals a choice of three gliding clubs; London, Chilterns, Booker, and Surrey Hills within 25 miles, and as a bonus all but Surrey Hills are a Junior gliding centre. Take your pick Steven!
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Following his trial flight junior William Stevens receives his certificate from Phil
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Mean while the Duty Instructor shifted targets to Osmet jr, AKA David, to continue his training. I flew a set of three flights with "Treasure" to start his training after his introduction to gliding last Sunday; lookout, elevator, ailerons, and rudder. At the end of the set he was reinforcing his control of the glider in roll and pitch and gaining confidence. A great start.
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Anyone for a stub landing? The Duty Instructor's view of the airfield from the south
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Junior Jamie then flew with Mike on a pair of flights that would stretch his abilities. This included a challenging launch failure exercise which Jamie executed flawlessly. Those pilots who weren't training were all enjoying extended flights under the almost 100% cloud cover. Throughout out the day there were tantalising glimpses of blue sky but no sunshine was to be had. Despite that it was surprising mild in the almost calm conditions.
Whilst Mike moved on to take David Moorley for a pair of flights Peter was busy with a type conversion brief for John Osmet in the K-8. Over thirty years ago John had flown K-8s regularly but a briefing on its handling with a high power winch, from a hill top site, was required before letting him go!
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CB SIFT BEC done John Osmet is ready for his first launch in K-8, GDK
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John landed 12 minutes later demonstrating that he found some gentle rising air and that indeed he hadn't forgotten how to soar. A second flight confirmed that he hadn't lost this valuable skill.
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John Osmet returns from his second soaring flight in GDK
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Mike then continued members' training with a pair of flights with Neal. David Bourchier came up from the hangar wanting to fly. I obliged him with two flights in K-13, FSD where David kept his hand in with some upper air work. Time was moving on now that we are in a new time zone; GMT or Zulu time, so Phil asked me to fly his second visitor while he finished off David's One Day Course.
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The Puchacz on the downwind leg spotted in the distance
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Ian Hutchinson was given a trial flight voucher by his wife for his birthday who came with him to the airfield to spectate. Proceedings delayed his flight time a little but that didn't stop Ian thoroughly enjoying his flight and having a go at using the controls. Ian is a musician (a drummer, who might be useful addition to Colin's band). A recent BGA club development seminar revealed that statistically musicians are more likely to become glider pilots than other groups in society. So who knows, we may see Ian back? He will of course be most welcome.
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Ian Hutchinson and Gavin ready to launch in K-13, FSD
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The smiling face says it all. Ian receives his post flight certificate from Gavin
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The Duty Instructor conducted his final pair of flights with Junior Toby
who has been away for a while. Mum, Sarah, also came up to the launch
point to watch him fly after spending most of the day in the clubhouse making use of the
Wi-Fi on her day job i.e. the thing that pays for Toby's flying!
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Well back Toby! Mum, Sarah, observes in the background
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At the end of the day Dave Archer came up to the launch point having been busy with Colin conducting the annual inspection of his K-6 CR, G-DHEB (Debbie to her friends!). The glider passed its inspection but with some paint needed here and there. DHEB is turning out to be a good investment (the glider and trailer were purchased last year for just £2,500. What a bargain and a lot of smiles and fun per £).
Dave enjoyed a circuit in K-8, GDK to keep his hand in before handing the glider to John Allan for the final flight of the day. John Allan managed to soar for 10 minutes, under a completely overcast sky, and he landed at 1657, two minutes after sunset. So what force was keep him and others a loft today?
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Phil and David Osmet manoeuvre the Puchacz before taking it back to the hangar.
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So with the day darkening it was time to pack up after 39 flights conducted in Zulu time. I am sure glider pilots would prefer that we stayed in BST all year round. The temperature was dropping and it was time for coats and woolly hats. All had had their fill, thanks to the stalwart winch drivers, albeit the number of trainees had been limited to training sets of two vice three flights. Note to self; must grow some more instructors!
So was Skysight's forecast correct with light rising air forecast on its "convergence" page? Studying the average time in the flight log of what should have been straight circuits, the extended reduced sink that Ian Hutchinson and I enjoyed during our flight, and John Allan's night time soaring, I would say Yes! Mother nature never ceases to amaze.
Gavin Short
