N-Jacko,
As far as I am aware, and I write this so as we can all learn:
CAP 738 (last update 2006) Safeguarding of Aerodromes, states:
(for a code 1 or 2 runway, ie the length of Strathaven or Insch)
*************
5.4.2 Where a main runway is less than 1800 m in length, the inner horizontal surface is
circular and is centred on the mid-point of the runway. The radius is 4000 m except in
the case of non-instrument runways where the code number is 1 or 2. For these
runways the radii are 2000 m and 2500 m respectively.
****************
So the traditional safeguarding zone for our airfields is 2km radius.
However, the later CAP 764 on wind energy (but not traditional obstacles such as blocks of flats, or mobile phone masts) states:
1.2 Aerodromes. Whilst not definitive, it should be anticipated that any wind turbine
development within the following criteria1 might have an impact upon civil
aerodrome- related operations:
........
e) Within 4 km of a non-radar equipped unlicensed aerodrome with a runway of
more than 800 m;
f) Within 3 km of a non-radar equipped unlicensed aerodrome with a runway of
less than 800 m.
1.3 The figures above are for initial guidance purposes only and do not represent
definitive ranges beyond which all wind turbine developments will be approved or
within which they will always be objected to. These ranges are intended as a prompt
for further discussion between developers and aviation stakeholders in the absence
of any other published criteria.
1.4 Many modern gliders have a glide ratio of at least 50:1 and the most modern gliders
can exceed that, with further progress expected in future. Developments of wind
turbines within 10 km of a gliding site will present additional considerations beyond
those associated with powered aircraft. Therefore, notwithstanding the CAA
recommended distances quoted above, the British Gliding Association (BGA)
requests that relevant gliding sites and the BGA are consulted where proposed
developments are within 10 km of any charted glider launch site.
**********************
So, unless on charts as a gliding site, we have a 3km radius for sub-800m runways.
But, this is only a starting point, and for wind turbines.
ps.
At Strathaven, we have an alternative wind measure, which has twice been proven at appeal.
We take the 2km zone, and then we take a 20 rotor diameter circle around a proposed turbine to allow for its turbulence. If the two zones overlap, we object. In other words, if the turbulence will infringe the basic 2km zone.
For turbines up to 50m rotor diameter, this gives the same as the 3km basic wind zone in CAP 764. 2km plus 20 x 50 = 3km.
But since we have turbines within five miles of us with 80m rotor diameters, you can our concerns over even a 3km zone!