When learning to fly a glider you usually remain close to the airfield. From the beginning through solo right up to the Bronze Badge, you must remain within safe gliding range of the airfield. After obtaining the Cross-Country Ensorsement you are then free to fly cross-coutry out of range of the airfield. Initially most pilots concentrate on the requirements for the Silver Badge.
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| A nice view from a DG100 somewhere else entirely |
I flew the aerotow OK and soon joined a thermal and circled a few times under the other Puchacz Whiskey Echo to gain a few hundred feet. Then I headed off further west towards Mount Keen via another couple of thermals and soon we were above 4000 feet. I will never cease to be amazed how you can 'steal' energy from the sky in order to climb so well without an engine.
I headed down Glen Tanar for a mile or so over scenes of desolation where major tree-felling had taken place. Not a nice place to try and land. I turned us gently back north west towards Ballater. I was staring to feel edgy that we were so far from the airfield and if we lost a bit of height we might not be high enough to get back. The instructor said that this was a healthy concern, but unnecessary as we had plenty of height in reserve. In still air, the Puchacz has a glide ratio of around 30:1, so for every 30 feet you fly horizontally you only lose one foot of height. So in principle from 1000 feet you could glide 30,000 feet - around 5 miles. Since we were currently around 4,000 feet, we could theoretically cover about 20 miles. Since we were only about 5 miles from the airfield we were clearly doing fine. Of course, the glide ratio is only a rough guide, and in troubled flying conditions like a strong headwind or heavy sink you still need to keep a decent height safety margin.
To illustrate this, the instructor suggested I head straight back for the airfield but at a higher-than-normal glide speed to minimise the effect of the big areas of sink we'd cross between any thermals on the way back. So as we reached the south side of Ballater, I turned us right 90 degrees pointing straight at the airfield, back along the river Dee. We were at the standard glide speed of 45 knots so I lowered the nose and held the new attitude and with a little adjustment the airspeed indicator soon settled at 70 knots. I re-trimmed and settled back for the ride - at this higher speed we were more stable than normal and as the air wasn't too rough today.
| Ballater |  |
Aboyne |
As we departed Ballater we were at 3,700 feet. As we sped back homewards I watched the altimeter unwind pleasingly slowly. I had plenty of time to look around at the usual great view with only the occasional minor adjustment on the controls to keep us straight and level. After a few short minutes the airfield began to slide under our nose, and as anticipated we had lost much less height than I expected: We were down to 2,700 feet so we had indeed covered several miles for a height loss of only 1,000 feet.
This was a very useful experience. When gliding it is important to make sure you do not stray too far and/or too low for a safe return to the airfield. But it is also important not to waste good flying opportunities by staying too close and/or too high. There is an imaginary inverted cone shape above the airfield within which you must remain. The cone is of course stretched and twisted by the prevailing winds, which change with altitude, so it is not too easy to visualise. But you get the idea. Of course, as a student, even after going solo, and even up to Bronze C standard, you cannot fly a glider too far from away from the airfield to prevent you from returning safely. You actually need a separate cross-country certificate in order to head of somewhere else to land. But with the potentially huge altitude gains available near Aboyne, you can still get rather far away while remaining in range of the airfield.
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| A bit further south - clifftops in Cornwall |
On another occasion I had thermalled to 3,500 feet near the airfield. The instructor suggested a navigation task: fly to Tarland then Aboyne then back to the airfield.
I looked north and saw Tarland in the distance, then turned slowly towards it. I maintained a speed of 45 knots and enjoyed the ride, with more time than usual to enjoy the view rather than just maintain a lookout. As we entered areas of sink I increased our speed to about 60 knots; if we hit lift I slowed again. That way I lost the least amount of height on the straight line route. At Tarland I flew around the east side to get a good view of the village. The instructor pointed out a large open field on the SE corner - the recommended "landing-out" field for gliders that cannot make it back to the airfield from this side. I remembered the day of my first flight when another glider had to land at Tarland due to a snow-storm.
After orbiting Tarland a few times, I headed south again towards Aboyne. I soon arrived over the village green where a few weeks earlier the Highland Games had been held. There was a fair bit of lift from the radiated heat of the village (mainly the heat of the sun from the asphalt roadways). I S-turned a few times looking for familiar roadside landmarks. For the first time I saw the true shape of Aboyne Loch, and also had a nice view of the golf course and castle. I made sure I stayed below 2,000 feet, well under the controlled airspace that starts at Aboyne and continues eastwards to Aberdeen (33 miles away) and beyond.