CAA Approve GPS approaches
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Wow, another bit of good news.
Except that the mandatory ATC requirement means they will appear only at airports with an existing instrument approach, which one could fly using a GPS for some years already....
But it's a good start.
Except that the mandatory ATC requirement means they will appear only at airports with an existing instrument approach, which one could fly using a GPS for some years already....
But it's a good start.
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Excellent news. All we need now is for them to drop the need for ADF. And modify the DME with "or other suitable measuring equipment" (GPS 
)
Mixed with the ELT news the CAA seem to be tracking in the right direction.
)Mixed with the ELT news the CAA seem to be tracking in the right direction.
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Wot no DME !
I dont think that dropping the DME is such a good idea, part of the checks when starting a GPS app is to check the GPS position, one of the best and most accurate ways of doing this is a VOR/DME fix.
I have flown the CAA trial and think that the GPS app is a real step forward BUT before getting that near the ground I want to know that the GPS kit is working as advertised.
I have flown the CAA trial and think that the GPS app is a real step forward BUT before getting that near the ground I want to know that the GPS kit is working as advertised.
And how do you check that the DME is working when you start an approach that needs it? I don't suppose it's much less vulnerable to obscure non-obvious failure modes than GPS. And there are some approaches round here where you'd look REALLY silly if you took a DME stepdown too soon...
n5296s
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And how do you check that the DME is working
You dont,
but if the DME and GPS agree then you are almost certainly where you think,
two totally independent systems telling you the same thing,
the problems start when they are telling you something different
.
You dont,
but if the DME and GPS agree then you are almost certainly where you think,
two totally independent systems telling you the same thing,
the problems start when they are telling you something different
.
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There is little chance of DME going away. It is firmly established on conventional approaches (e.g. ILS) and they will "never" go away. It's mandatory in many situations around the world.
Even in the USA, where an IFR GPS can susbstitute for a DME, you get problems with the choice of alternate if you don't have conventional navaid landing capability. And DME is mandatory above, can't remember, FL-something, as is Mode C.
I would never get rid of VOR/DME. It forms an essential backup for the GPS. Remember most pilots have only one GPS. I've had equipment failures and had to fall back on other stuff.
The real key to improving GA utility is doing away with mandatory ATC for instrument approaches. There is a lot of politics involved in this, including some ATC trade union issues (the unions are sure to object), and the "user pays" NATS charging practices (which would mean the airfield getting a bill from a nearby ATC unit for the "coordination") would need to be rethought. The simple solution (self announcement on a common approach frequency) is not likely to be accepted in the European anally retentive "safety" climate, even though it would clearly work perfectly well, and would be considerably safer than the currently perfectly legal practice of multiple arrivals carrying out DIY approaches non-radio in Class G.
Even in the USA, where an IFR GPS can susbstitute for a DME, you get problems with the choice of alternate if you don't have conventional navaid landing capability. And DME is mandatory above, can't remember, FL-something, as is Mode C.
I would never get rid of VOR/DME. It forms an essential backup for the GPS. Remember most pilots have only one GPS. I've had equipment failures and had to fall back on other stuff.
The real key to improving GA utility is doing away with mandatory ATC for instrument approaches. There is a lot of politics involved in this, including some ATC trade union issues (the unions are sure to object), and the "user pays" NATS charging practices (which would mean the airfield getting a bill from a nearby ATC unit for the "coordination") would need to be rethought. The simple solution (self announcement on a common approach frequency) is not likely to be accepted in the European anally retentive "safety" climate, even though it would clearly work perfectly well, and would be considerably safer than the currently perfectly legal practice of multiple arrivals carrying out DIY approaches non-radio in Class G.
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IO540, the NATS atco trade union (Prospect) would probably take no interest whatsoever in whether or not instrument approaches were allowed at non ATC airfields. They negotiate our terms and conditions of our employment. There are also other trade unions that represent non NATS ATC staff and I'm sure they wouldn't be that interested either.
The organisation that might take an interest is GATCO, the Guild of Air Traffic Control Officers (most definitely not a trade union), who like to represent all UK atcos (civil and mil) on professional matters. I am not a member so won't comment on what their position might be any further.
Stop banging on about the union on this subject, I doubt they'll take any notice.
The organisation that might take an interest is GATCO, the Guild of Air Traffic Control Officers (most definitely not a trade union), who like to represent all UK atcos (civil and mil) on professional matters. I am not a member so won't comment on what their position might be any further.
Stop banging on about the union on this subject, I doubt they'll take any notice.
but if the DME and GPS agree then you are almost certainly where you think,
But, since you are then almost certainly within a few feet of the ground, you should probably be looking out of the window, not at the instruments!
G
(Please excuse the flippancy - of-course this is a good thing, and no doubt as people start to use them, they'll become more widely available and may not mandate other instrument approaches also being available, which can only be good for GA, since it'll cut costs enormously, whilst expanding the usability of many airfields.)
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Come on you lot; the difference between GPS and DME is under 0.1nm in almost any flying context.
Work out the cos of 3 degrees! It's 0.9986. The difference is negligible, on a 3 degree ILS.
Work out the cos of 3 degrees! It's 0.9986. The difference is negligible, on a 3 degree ILS.
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My point was to remove the mandatory requirement for carriage. The French and USA have done this. However it would still be required for any approach that actually stated its use - same as an NDB. I can see that around Europe (in the not too distant future) that some airfields would be GPS only..
and some day maybe even a FISO could be allowed to handle it.
and some day maybe even a FISO could be allowed to handle it.
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DF
Interesting point.
Leaving aside the possibility of GPS failure (and I encompass in that either the aircraft born unit(s) or the external system (due to interference with the signal for example), and given in these circumstances you could (and would) fly an alternative approach using different instruments, would you ever be happy with completly relying on a GPS approach without any other positional cross check in circumstances where a gross error would place you in terrain before becoming visual?
If so why?
(and for the avoidance of doubt it is a genuine discussion point and not because I am expressing a particular view one way or the other or trying to say it would be irresponsible to do so).
Interesting point.
Leaving aside the possibility of GPS failure (and I encompass in that either the aircraft born unit(s) or the external system (due to interference with the signal for example), and given in these circumstances you could (and would) fly an alternative approach using different instruments, would you ever be happy with completly relying on a GPS approach without any other positional cross check in circumstances where a gross error would place you in terrain before becoming visual?
If so why?
(and for the avoidance of doubt it is a genuine discussion point and not because I am expressing a particular view one way or the other or trying to say it would be irresponsible to do so).
The real key to improving GA utility is doing away with mandatory ATC for instrument approaches. There is a lot of politics involved in this, including some ATC trade union issues (the unions are sure to object), and the "user pays" NATS charging practices (which would mean the airfield getting a bill from a nearby ATC unit for the "coordination") would need to be rethought. The simple solution (self announcement on a common approach frequency) is not likely to be accepted in the European anally retentive "safety" climate, even though it would clearly work perfectly well, and would be considerably safer than the currently perfectly legal practice of multiple arrivals carrying out DIY approaches non-radio in Class G.
The fact that some fly DIY approaches without ATC is not a reason for changing the current rules and the CAA approval of GPS (which I endorse) will no doubt mean that we will see more of this activity.
This has been covered on other threads before I know!
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Why a licensed ATCO, FFB?
I also wouldn't worry about too many pilots trying to do this in the same location at the same time. Get in the air on any BKN008 or worse day and the sky is like a cemetery - almost nobody up there. You can even get an RIS from Gatwick Director. 99% of UK GA is doing burger runs on nice days...
The # of UK pilots carrying TSOd GPS units is tiny. Most of them are N-reg; this was obvious from the poor participation in the CAA GPS trial. Very few UK PPLs flying a G-reg have an IR, and IMC Rated pilots don't need an IFR GPS with a current database costing a couple of hundred quid a year to keep updated. These people won't be able to fly the GPS approaches - well, no more than they can fly any DIY approach right now with their handheld unit. With the sort of decision heights we will be getting on GPS approaches, working out a DIY letdown (GPS, or VOR/DME) from the 1:50k O/S chart is very easy.
When non-ATC airfields get GPS approaches, the utility value in GA will improve significantly but I predict it will take a little while to filter down into more activity all around. For that, we will need a lot of avionics upgrades, and a lot more new aircraft. Still, it's very good news.
I also wouldn't worry about too many pilots trying to do this in the same location at the same time. Get in the air on any BKN008 or worse day and the sky is like a cemetery - almost nobody up there. You can even get an RIS from Gatwick Director. 99% of UK GA is doing burger runs on nice days...
The # of UK pilots carrying TSOd GPS units is tiny. Most of them are N-reg; this was obvious from the poor participation in the CAA GPS trial. Very few UK PPLs flying a G-reg have an IR, and IMC Rated pilots don't need an IFR GPS with a current database costing a couple of hundred quid a year to keep updated. These people won't be able to fly the GPS approaches - well, no more than they can fly any DIY approach right now with their handheld unit. With the sort of decision heights we will be getting on GPS approaches, working out a DIY letdown (GPS, or VOR/DME) from the 1:50k O/S chart is very easy.
When non-ATC airfields get GPS approaches, the utility value in GA will improve significantly but I predict it will take a little while to filter down into more activity all around. For that, we will need a lot of avionics upgrades, and a lot more new aircraft. Still, it's very good news.
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but if the DME and GPS agree then you are almost certainly where you think.
Come on you lot; the difference between GPS and DME is under 0.1nm in almost any flying context.
And how do you check that the DME is working when you start an approach that needs it?
would you ever be happy with completly relying on a GPS approach without any other positional cross check in circumstances where a gross error would place you in terrain before becoming visual?
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If not why not?
http://youtube.com/watch?v=GelRBhJ4gmI
One possible reason where relying on something as "reliable" as a localiser without a cross check proved fatal.
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Even the slant distance at the start of a typical base turn you see probably about a 0.5nm difference