Hi again mates.
Well this time let's see how we can use the ARP Fix of the airports that have a diagram in order to we have an almost precise "non precision" approach.
This method can be used ONLY to airports that have a diagram and are a sigle RWY type with RWY length of 8,666 FT. Also the RWY should not have any displaced thresholds, like the new Kasteli airbase.
So the sigle RWY type airports have RWY of 8,666 FT. The ARP Fix is perfectly in the middle of the RWY and over the centerline. That means that the ARP is exactly at 8,666/2=4,333 FT from each one RWY threshold or 4,333/6,076=0.71 NM -> 0.7 NM.
Now for a 2.5 deg. descent for 4 NM we have 265FT/NM x 4NM= 1,060 FT.
Finally our FAF will be at 4.7 DME from the ARP of the airport and at 1,060 FT above the RWY elevation with a 2.5 deg. slope.
As an example i will use the Ifaistos airport in north Aegean sea.
The imaginary case is that i was had a missed TACAN approach to RWY 03 on Ifaistos airport (the published one), and now i'm low on fuel and the nearest airport is the Megas Alexandros at north at 65 NM... Weather is bad with low fog that gives visibility of 0.7 NM (set from 0 FT to 4,255 FT).
I have only fuel for one last approach and i'm already stressed in order to make it.
Ifaistos airport has no ILS at both RWY's, so my last chance will be the usage of the ARP:
FAF will be at 4.7 DME of ARP Fix, at 1,070 FT (1,060 FT + 10 FT RWY elevation) on ARP R-210 inbound with heading of 030 deg. for an approach to RWY 03.
Below i'm exactly at FAF (4.7 DME of ARP Fix at 1,070 FT on ARP R-210 inbound) ready to start my 2.5 deg. descent
Below i'm at ARP 1.3 DME (or at 1.3-0.7=0.6 NM from RWY threshold) and the RWY just be in sight (visibility set at 0.7 NM)
Since i'm keeping the CDI centered at HSI i'm very well aligned with RWY, see below at ARP 55/61=0.9 DME (or at 0.9-0.7=0.2 NM from RWY threshold)
Finally i had an easy and smooth touch down on RWY 03 of Ifaistos airport
So let's summarize this method:
- Use it ONLY at airports with single RWY that has length of 8,666 FT and NO displaced threshold! This airport must have a diagram to get the ARP GPS coordinates.
- Altitude of FAF 1,060 FT + RWY elevation.
- FAF at ARP 4.7 DME at calculated altitude on Radial of opposite RWY with an inbound course and a 2.5 deg. descent.
- Touch down will be at 0.7 DME (43/61).
- Be advised: DO NOT place the FPM over the STPT sign (diamond)! Place it over the 2.5 deg. pitch dive ladder!
If you have any questions feel free to ask. My pleasure to help you.
Nikos.