ILS Lower Than Standard Category 1
The drawback with LTSC 1 ops, as I understand it, is the requirement for additional on board equipment in the form of HUD or EVS and associated crew training. The total costs would be considerable and an airline would question whether the expenditure was justifiable.
The range of RVRs in which the benefit could be gained will be roughly in the region of 400-700m.. In the UK RVRs of these values tend to be transient, in that they are most likely to be found when fog is in process of clearing or forming. The advantage period can be short. Mature fogs tend to stabilise at a much lower figure such that only Cat 3 is possible.
I can understand .that SEN management looked at LTSC 1 and I suspect I know why they did not proceed with it. To the airport it may have looked like an economical way to achieve lower operating minima in that there was presumably no requirement for extra ground equipment. There would still be the certification costs, and as we know CAA costs tend to be not insubstantial.
So they could spend the money only to find there was no operator ready or willing to use the facility.
Last edited by Tagron; 26th Apr 2017 at 23:06.
Reason: Full title