Malibuflyer wrote:
Yes, because for the time being they can only regulate it for such aircraft – but one could see this regulation as move towards leaving EASA
The proposed changes to part-NCO concerning IFR will permit fix substitution by adding a new AMC — i.e. without changing the actual implementation rule (NCO.IDE.A.195).
What would prevent the UK CAA (or any other NAA) to simply publish an AltMOC permitting fix substitution?
johnh wrote:
As far as pre-ILS ILS-like approaches go, the town of Dovercourt, Essex, where I spent my childhood summer holidays, had two lighthouses which functioned as a kind of ILS for the harbour approach from 1863 to 1917 – amazingly, the lighthouses are still there and preserved. You had to keep them lined up, and there was a way to know which way you were off course if not (one was higher than the other)
This is still today a common arrangement at least in small harbours — both with lights and with unlighted markers.
Airborne_Again wrote:
What would prevent the UK CAA (or any other NAA) to simply publish an AltMOC permitting fix substitution?
Theoretically this might be an option – practically it would be extremely difficult and create much more uncertainties for pilots than it would help (starting with the question who would fall under these MOCs and who not – it would only be a solution for pilots with a UK-license in a UK-registered plane flying within the UK airspace). If they wanted to, it would be much easier to go “the FAA way” which is just publicly announce that they will not prosecute certain transgressions.
Even though I can’t quote a regulation that would be against it, I’m actually quite happy that not every CAA in Europe publishes their own AltMOC manual so that in the end we face 30 different regulations again.
Malibuflyer wrote:
(starting with the question who would fall under these MOCs and who not – it would only be a solution for pilots with a UK-license in a UK-registered plane flying within the UK airspace)
That’s not my understanding of how AltMOCs work. (At least not as long as the UK effectively remains in EASA.)
I think there are two separate issues:
(1) Aircraft operations: Is it safe/ok to substitute ADF with GPS?
(2) Airspace regulations: Minimum aircraft equipment for airspace use
(1) is an EASA/EC responsibility as per part-NCO or other applicable aircraft operations regulation (part-NCC etc).
(2) is a national airspace owner decision. For instance, Germany and the UK have different minimum aircraft equipment requirements for airspace use.
It might be a legally risky situation for (1) but the AMC are not binding but are an EASA-articulated acceptable means of compliance. Aircraft operators could come up with their own means of compliance if it can be justified. Presumably (although legally risky) there is leeway to justify GPS substitution for ADF.
What about (2) though? Presumably that is a hard fact as enshrined in regulation? So even if the aircraft operator deems ADF subsitution acceptable, if the airspace owner doesn’t allow it or requires ADF as minimum aircraft equipment, I would still need an ADF if I end up not using it.
wbardorf wrote:
(2) is a national airspace owner decision. For instance, Germany and the UK have different minimum aircraft equipment requirements for airspace use.
Actually, no. Neither Germany nor the UK can prescribe minimum aircraft equipment for airspace use except what they are explicitly allowed to require by EU regulations. So they are allowed to require e.g. mode S transponders, but not a DME.
@wbardorf, my understanding of national regulations regarding airspace use, as mentioned in 2) of your post, is related to required equipment for operating in the national airspace. For example, the regulations in this area apply to the need for 8.33Hz radio(s), S-transponders, etc. Required equipment to execute a given IAP does not seem to me to fall under regulations related to the use of airspace.
Applying the US regulation to flying an N-reg in Europe where the existence of traditional navaid IAPs (beyond ILS) is still fairly common, there are a couple of situations:
- as mentioned, any IAP with GPS in the title can be flown with reference only to WAAS GPS…. e.g. (GPS) VOR Rwy xx or (GPS) NDB Rwy xx.
- any IAP without GPS in the title requires that the indicated navaid and aircraft radios be operational and used for final segment course alignment, but an RNAV system can be used to navigate on the final course segment (i.e. identify waypoints … FAF, MAP, etc). For example, and aircraft with WAAS GPS, VOR/GS but no DME or NDB could fly the LDLO VOR Rwy 02 approach but not the LDLO NDB Rwy 02 approach.
Arne wrote:
The opinion for this reg was published recently, and the proposed GM essentially reverses the NPA, where RNAV is specifically not allowed as a replacement for DME on the final segment.
It’s actually in the AMC earlier on the same page which says,
RNAV substitution may be used in all the phases of flight except:
(1) to provide lateral guidance in the final approach segment of an instrument approach procedure;
and
(2) to substitute for DME, if a DME transceiver is either not installed on the aircraft or found to be unserviceable before flight
So you may not substitute for DME at all unless as a contingency measure if you have a DME which fails in flight.
There was a discussion about this in the PPL/IR forum and apparently what changed the mind of the EASA committee were the potential risks with substituting offset DMEs or using the incorrect waypoint when there is another facility with the same id which is not co-located with the DME. The Dundee crash was specifically mentioned. I still think that the reversal is surprising since these issues were well known and discussed both here on EuroGA and on the PPL/IR forum before the NPA was written.
But, as was pointed out in that discussion, you can make your own AltMOCs for part-NCO. I personally don’t see any issues with substituting a DME-based fix which is co-located with an RNAV waypoint, nor with flying a DME arc which is included in the navigator database.
Airborne_Again wrote:
RNAV substitution may be used in all the phases of flight except:
(1) to provide lateral guidance in the final approach segment of an instrument approach procedure
In what cases DME provides lateral guidance on final segment? DME arc? DME distance?
That wording seems to point GPS can’t be used to track VOR/NDB radials between FAF/FAP and MAPt
GPS to give DME distance on final segment should be ok?
