As peter says the without Form 1 concession doen’t exist in the UK
Peter have a look at the minima at Kemble or Sywell there basically 500 feet.
There is a similar reason (but I can’t quite remember why) that the Scilly Iises still have a timed NDB approach. If they got a GPS approach the minima would be higher.
Bathman wrote:
Sorry I don’t have the option of a 430W its a 400 or a 400W. I have edited my first post.So I can fit a 400 or a 400W.
The “W” is a bit moot here in the UK at the moment as 3D GPS approaches are no longer available. Also the CAA have put a 500 foot minima on all GPS approaches outside controlled airspace so the LNAV and LPV minima are basically the same anyway.
On 430W, for example, you will get +V on it, which is very convenient. Plus it is not going to be the 0.3nm TSE all the way down – it will be angular, improving closer to the threshold (despite SoL not longer used in the UK). Please also note that despite LPV not being available in the UK (still can used in Europe!), LNAV/VNAV is still OK (not to be confused with BaroVNAV). All the vertical features are available on W-device only.
Otherwise, what is the difference between 400W+installation cost (including paperwork and antennae) vs GTN650 + installation cost (including paperwork and antennae)?
It might be not that big…
Peter have a look at the minima at Kemble or Sywell there basically 500 feet.
Sure, nonprecision IAP design… nothing to do with 500ft min and everything to do with getting the CAA old farts to approve it, against their will. It’s like Planning; if you spend another 10k on a consultant, you get a better result, but you have to decide to cut your losses at some point, and these airports get minimal extra income due to the IAP. The exception disproves the “rule” – see EGKA which is below 500ft (on 02).
The Sywell IAP is near-useless anyway. The CAA really didn’t want Sywell getting an IAP – see here because they are doing it without an ATCO and one on the approach approved pay grade, which breaks “all the rules” on airspace management job demarcation.
There is a similar reason (but I can’t quite remember why) that the Scilly Iises still have a timed NDB approach.
The only customer of relevance being able to scud run all the way at 500ft (which they do frequently). Also those planes are old wrecks which probably can’t fly a GPS IAP. Otherwise, that route is worth millions a year (look at how much was spent on Lands End airport, and they try hard to keep GA out of there despite that.
If they got a GPS approach the minima would be higher.
No evidence for that, sorry 
for example, you will get +V on it, which is very convenient
Exactly – +V remains despite the Brussels block, but it would do anyway with latest firmware because that gives you +V without EGNOS. Worth noting that you get +V only where a GPS IAP is published. However I suspect +V is of no use to the OP since this is a school scenario and I doubt they train +V in the IMCR.
Please keep this thread on the topic. A better thread for minima is here so please post material on why we have “useless” minima in so many places, there. Nobody who actually knows (i.e. who paid the consultant and the CAA) is going to be posting details openly (it is their £££ business) but it is known that a lot of the time the overriding DH is due to low assumed climb performance on the missed approach.
Bathman wrote:
As peter says the without Form 1 concession doen’t exist in the UK
It’s one thing that UK avionics shops generally may not want to accept owner-approved parts, but AFAIU, all EASA regulations were incorporated into UK law with the Brexit act.
The problem is the Ops inspector that inspects the maintenance out fit. They disagree with the regulations and it doesn’t matter what you say if the maintenance outfit doesn’t do what their Ops inspector says they pull you approval.
arj1 wrote:
Otherwise, what is the difference between 400W+installation cost (including paperwork and antennae) vs GTN650 + installation cost (including paperwork and antennae)?
About 7K compared to the purchase and fitting costs of a 400 (no WAAS)
It’s not just the UK… but the usual pattern is that few non UK people want to badmouth their own country on EuroGA, whereas Brits are very happy to I hear privately that lots of shops on the mainland won’t touch this with a 20ft (7m) bargepole. And one can see why – reason above.
In most cases you have a choice of maybe 1 shop within easy driving range, and if you upset them (if you cite some law, they will tell you to never come back – I posted one email here) you have to go much further out. And as this chap found out, you should never use a shop which is really far away (same story with getting work done on a house when you aren’t around).
The problem is the Ops inspector that inspects the maintenance out fit. They disagree with the regulations and it doesn’t matter what you say if the maintenance outfit doesn’t do what their Ops inspector says they pull you approval.
Yes, the CAA have as much power here as the local police have over a gun shop.
But this applies to a school, much more than to a private owner who merely needs to find an installer.
