Flying
We do our flying at The Ulster Gliding Club's airfield in Bellarena, Co. Londonderry. This hilly area is ideally suited for gliding and making the most of Northern Irish conditions. The prevailing wind is forced upwards (creating what is called "ridge lift") at Binevenagh, an impressive mountain near the airfield (pictured below). As I'm sure you are aware, Ireland is a rather windy place, and Binevenagh will give us good ridge lift with wind from the north, west, and south.
When air rises to go over a mountain, it is also sucked down again on the other side. When conditions are suitable however, it is then forced up again and continues to rise and fall in a wavelike manner. This wave can reach heights far in excess of the mountain that initially triggered it, and extend sometimes for a hundred miles downwind. Very unimaginatively, this is called a wave system, and by flying along the wave "bars" where they are moving upwards we can reach higher altitudes than any other lift type offers. Sometimes we can climb in wave so high we are legally required to use oxygen! At Bellarena the altitude record is over 23,000ft (7km). Since we have the Sperrin and Donegal mountains nearby, Bellarena gets more than its fair share of wave flying days.
In summer, and occasionally in winter, on sunny days rising thermals allow form. these occur when some area of ground warms up faster than its surroundings, and you get a correspondingly warmer pocket of air there. This pocket of air eventually detaches and streams upwards. By circling in these thermals we can climb. When the air is relatively humid, the water vapour is carried up with the air until it reaches the dew point, where the temperature causes it to condense into a fluffy cumulus cloud, and gives us a perfect visual marker of where lift can be found.
Unfortunately being next to the sea means that often cool wind from the water weakens or eliminated the thermals much of the time and consequently we do not have nearly so many good thermic days as the rest of the UK, let alone continental europe. Nevertheless our almost unparalleled access to ridge and wave flying means we can enjoy good flying all year, especially satisfying in deepest winter when the thermal dependant UK clubs in flat areas can only drink tea and grumble looking skywards as we contact wave in Northern Ireland.
