OCA on Gloucester RNAV plate
Thread Starter
Joined: Feb 2003
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From: Oxford
OCA on Gloucester RNAV plate
On the Gloucester RNAV (GNSS) 09 plate here:
http://www.ead.eurocontrol.int/eadba...2013-05-30.pdf
there are two Procedure LNAV OCAs given, one 'At 3.2% MAP' and one 'At 2.5% MAP'. The latter is higher.
What do these mean? (Neither relates to the 'recommended profile' of 5.24%)
http://www.ead.eurocontrol.int/eadba...2013-05-30.pdf
there are two Procedure LNAV OCAs given, one 'At 3.2% MAP' and one 'At 2.5% MAP'. The latter is higher.
What do these mean? (Neither relates to the 'recommended profile' of 5.24%)

Joined: Aug 2004
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From: Home
Trouble is the CAA have made the ATC requirements and paperwork costs of setting up an RNAV app in the UK so outrageously expensive you will never see many here.
Considering the safety case and lack of infrastructure required by an airfield the cost should be minimal. All the required kit already in place, satellites up there and Avionics in the aircraft.
GPS overlay approaches on present NDB and VOR procedures could be published immediately and at minimal cost as was done in USA decades ago.
Small non ATC US airfield I visited had a GPS/LPV approach in place at each end of their runway in about 3 months at a cost of less than $20000.
And didn’t charge the usual UK £20/40 a go to use it.
Considering the safety case and lack of infrastructure required by an airfield the cost should be minimal. All the required kit already in place, satellites up there and Avionics in the aircraft.
GPS overlay approaches on present NDB and VOR procedures could be published immediately and at minimal cost as was done in USA decades ago.
Small non ATC US airfield I visited had a GPS/LPV approach in place at each end of their runway in about 3 months at a cost of less than $20000.
And didn’t charge the usual UK £20/40 a go to use it.
Thread Starter
Joined: Feb 2003
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From: Oxford
What’s the RT procedure for this outside controlled airspace? Do I just call with an estimate for the IAF and ask for a level? And what happens if they need to delay me - will they hold me at the IAF (no published hold) or the published hold at GST? (If the latter then I would need then to proceed to one of the arms of the T afterwards, presumably.)

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From: north of barlu
Cessnapete
Overlay and GPS substitution for DME have issues in Europe because some ground based radio aids that are closely located have the same ident. This could result in the wrong radio aid being substituted in the GPS and a plausible approach being carried out. In North America radio aids with identical idents have to be geographically separated by 500nm producing a gross error of a wrong substituted nav aid totaly implausible.
An example of this can be found at LCLK, the LCA VOR is at the eastern end of the airfield and the LCA NDB is about 4NM west of the airfield , selection of the wrong LCA in the GPS database could result in a plausible approach being made on the wrong location.
Only when Europe adopts the same identical IDENT policy as North America will overlay and DME substitution become viable.
This however does not prohibit using the GPS data and more user friendly presentation to fly any approach provided you also have the conventional aids selected in the aircraft and displayed as the master.
An example of this can be found at LCLK, the LCA VOR is at the eastern end of the airfield and the LCA NDB is about 4NM west of the airfield , selection of the wrong LCA in the GPS database could result in a plausible approach being made on the wrong location.
Only when Europe adopts the same identical IDENT policy as North America will overlay and DME substitution become viable.
This however does not prohibit using the GPS data and more user friendly presentation to fly any approach provided you also have the conventional aids selected in the aircraft and displayed as the master.
Last edited by A and C; 15th October 2017 at 08:00.
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From: Cambridge, England, EU
Joined: Jun 2012
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From: Cambridge
I guess also for airfields having all traffic using the same holding fix regardless of what approach they're wanting to do might make procedural separation easier etc?

Joined: Oct 2001
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From: Starring at an Airfield Near you
https://publicapps.caa.co.uk/docs/33...16%20amend.pdf





