Evening Flights

Summary

Restitution Lift

About two hours before sunset, the thermodynamic breeze at take off will begin to moderate and on the best days pilots will be able to enjoy huge smooth restitution lift along the length of the mountain.

Catabatic Wind

As the sun drops a catabatic wind will develop on the lower parts of the slope especially in the easterly facing sections of the bowls. This catabatic wind does not extend more than a few kilometres into the valley and the leading edge of it will kick up an area of lift (restitution/convergence with the geostrophic wind), which will often form clouds out in the valley long after all other cumulus have died out. When this happens you will often be able to fly up to 6 kilometres in front of the mountain in very smooth lift. This often occurs around sunset, so you should be aware that your landing may be at twilight.

Large Scale Convergence / Restitution Effect

Occasionally, a very long cloud will form from a few kilometres out front of the mountain to many kilometres behind and go from western to eastern horizons (from the Tornavacas pass to beyond Avila). This will sometimes happen with a level of higher stratus. It may also be that the wind smooths off, but does not drop, so we may have to take off at the lower launch points. During the 2007 nationals in Piedrahita a similar effect set up and some pilots were still flying 30 minutes after sunset to land near Avila after launching after 7pm. See the video of takeoff. This is a very large scale convergence / restitution effect, but unfortunately comes on too late in the day for us to benefit with long XCs. For our evening flight we normally confine ourselves to smaller tasks within the valley. This is primarily a relaxing flight before going for a beer and dinner.

Strong North Or North Easterly Wind

With these conditions the take off area can be turbulent and we sometimes use a take off below Peña Negra rock. It is easy to stay up on the NE face in front of Peña Negra, but very difficult to get very far along the ridge to the east without finding rotor turbulence from the Big Spine. Flying to the west is ok for two bowls, but difficult to return. Flying downwind towards El Barco is not recommended, as the compression winds at the end of the ridge (approximately 5km) can be quite strong.

Evening Flight Challenges

1. The Corrals And Back

There are various challenges that pilots can set themselves. Out and returns along the ridge are often easily achieved during the evening flight. The classic is the Corrals and back (Turnpoint 4) which is 16.8km. This can be very difficult earlier in the day, but in the evening if the restitution sets up or the wind is above 10km and between NW and N, it is a simple ridge soar. It the wind goes too far to the North it can be difficult to get around the Big Spine and there may be some rotor on the western face. If the lift is not abundant, and you need to use certain sections to gain height before moving on, then it maybe prudent to stop before the Corrals, normally at the Zig Zag Track, after which the mountain drops in height and the ridge lift less abundant.

2. Flight To The Long Bar (El Lavadero).

If the wind is very west and quite strong, then only the westerly facing parts of the bowls will work. You will be able to fly along the mountain towards the east with the tailwind, gaining height on each westerly spine, but will find it difficult to return. In this case we usually end our flight at the Long Bar which as a large landing field in front of its terrace. This is a good place to chill out with a beer at the end of the flying, with the setting sun often making the whole mountain to appear to glow red.

3. Cerro La Cruz.

The Cerro La Cruz ridge is the small chain of hills running parallel to the main mountain, starting just to the west of Piedrahita, the crest being some 6.5 kilometres out in front of take off. If you get onto the front of this ridge, it is generally ridge soarable along its face to Hoyoredondo in the late afternoon. This is often a favourite competition task after returning from Avila, since it can be achieved very late in the day climbing high on the ridge in the last thermals, or even in the restitution. There are various possible routes to get there. If you think you will get there low, it is best to approach from around the end of the hill as it rises up from Piedrahita. If you can be sure to get high, then you can cross its crest further to the west. A favourite way to cross is to run the main ridge until you are near Santiago de Collado, and to take the glide from there. It is common for there to be a good climb at the col, halfway across the glide to the Cerro La Cruz ridge, so you can top up and cross the spine back with ample height. When coming back to the landing field, you can normally make it in leaving at the height of the cross on top of the pinnacle of the hill nearest to Piedrahita.

4. Flights To The River And Back The Centre Of The Valley

The Corneja River is 8km directly out in front of take off. On strong restitution and convergence days this is an interesting flight do. When possible, it is also of course easy to do the ridge run towards Villafranca, so we often do that first, and then on the way back start moving out into the valley. There are days when they will be smooth lift right out into the valley to the river. At other times the restitution and ridge lift may have dropped of after a few kilometres out. In that case you may have to climb in some of the last thermals coming out of the flatlands to get to the river. The river area itself often triggers thermals. It is often a good line to take when flying across the middle of the valley.