[TVHGC Members] Liddington Castle

For the benefit of those seeking some guidance as to what is flyable and what is less so, I have established, from the BHPA sites database that Liddington is registered as "usable" between 220 and 340 degrees.

This seems to conflict with our sites guide which indicates two distinct sectors of "usability", one facing NW the other SW +- about 15 degrees.

I believe the ideal direction for the NW side is indeed NW (315 deg) which is a bit off top the left and, if the "most northerly" as per the database is correct, plus or minus 25 degrees i.e. 290 to 340.

The ridge itself lies such that "square on" is around 325 deg. So usable from around 15 deg off to the right through to around 35 degrees off to the left.

But the hill goes on round the corner and has a face into the wind (albeit rounded) all the way to the SW side so why do I believe it is not usable in the sector 290 to 260?

This is because my assessment of the aerology. The ridge continues in a descending but marked spur all the way to the A 346 and there are huge areas of thermal generator to both sides. The warmed air migrates towards the spur on both the windward and leeward sides and, when the wind is "On" i.e. more northerly than 290, that air triggers at the base of the hill and flows around the back of the hill.

BUT when the wind goes south of 290 (I use this point as a limit but it will depend on many factors on the day) then the wind may blow the triggering thermal across the face of the hill and ridge-soaring will be disrupted by thermic action across the face of the hill. This can be very turbulent when the wind is strong enough to ridge soar the hill at that wind angle.

Obviously if there is no thermic action then this does not apply but in that case the hill is barely soarable anyway unless the wind is very strong.

All the above is only my own limited assessment of the hill with which I set my limits of "flyability" for direction and strength when doing my site assessment.

I set it out here in case it is of any value to anyone else puzzling over the same issues.

If I want to "push my limits" I might try in slightly stronger winds but probably not outside the direction limits set out above and the stronger the wind the squarer I prefer to try it in.

I have come to these conclusions from my reading of our sites guide. They give me some limits within which I determine my flying.

--
--
You received this message because you are subscribed to the Google Groups "TVHGC members list" group.
To post to this group, send email to TVHGC_Members@googlegroups.com
To unsubscribe from this group, send email to TVHGC_Members-unsubscribe@googlegroups.com
For more options, visit this group at http://groups.google.co.uk/group/TVHGC_Members?hl=en-GB
Please note that TVHGC may withdraw any posted messages deemed
unsuitable but does not generally endorse any posted content.
---
You received this message because you are subscribed to the Google Groups "TVHGC members list" group.
To unsubscribe from this group and stop receiving emails from it, send an email to tvhgc_members+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.