Can't DND increase the pattern height for the Cat C 09 ILS approach from 2,200ft to 3000ft or greater in circumstances when extended finals are necessary? This would increase vertical separation with VFR traffic in the vicinity of Scone and reduce the risk of terrain degrading or masking the ILS.
Another potential solution would be a steeper glidepath. The Q400 and D328 are both able to use LCY which has a 5.5 degree glidepath although this requires additional crew training and wouldn't be suitable for many aircraft types and crews. Even a slight increase in glideslope angle would be helpful though.
In the 80s and 90s, MLS was being developed and had the advantage over ILS of allowing final approaches that were not straight. This might have been ideal for DND but the technology was abandoned in favour of GPS/WAAS/EGNOS/LPV which has yet to be approved for DND. According to Wikipedia, as of Sept 2014 it was only approved for 114 European airfields.
Last edited by Porrohman; 28th Dec 2016 at 11:59.
Reason: typo